Larvae of the North American Caddisfly Genera (Trichoptera) 9781442623606

Citation preview

Larvae of the North American Caddisfly Genera (Trichoptera) Second edition Caddisflies are one o f the most diverse groups o f organisms living in freshwater habitats, and their larvae are involved in energy transfer at several levels within these communities. Caddisfly larvae are also remarkable because o f the exquisite food-catching nets and portable cases they construct with silk and selected pieces o f plant and rock materials. This book is the most comprehensive existing reference on the aquatic larval stages o f the 149 Nearctic genera o f Trichoptera, comprising more than 1400 species i n North America. The book is invaluable for freshwater biologists and ecologists i n identifying caddisflies i n the communities they study, for students o f aquatic biology as a guide to the diverse fauna of freshwater habitats, and for systematic entomologists as an atlas o f the larval morphology of Trichoptera. I n the General Section, the biology o f caddisfly larvae is considered from an evolutionary point o f view. Morphological terms are discussed and illustrated and a classification o f the Nearctic genera is given. Techniques are outlined for collecting and preserving larval specimens and for associating larval with adult stages. The Systematic Section begins w i t h a key to larvae of the 26 families of North American Trichoptera. Each chapter i n this section is devoted to a particular family, providing a summary of biological features and a key to genera, followed by a two-page outline for each genus w i t h illustrations facing text. This outline provides information on general distribution, number o f species, distinctive morphological features, and biological data including construction behaviour. A n important feature o f the book is the habitus illustrations of larvae and cases o f a selected species in each genus, along w i t h illustrations of details of significant morphological structures. Each generic type is thus presented as a recognizable whole organism adapted in elegant ways to particular niches o f freshwater communities. This revised edition includes advances i n knowledge on the classification and biology of Trichoptera up to 1993 - an interval o f 17 years since the first edition. A n additional eight families and thirteen genera are included for the first time. Through reorganization o f the families into three suborders, a biological context has been established for the systematic section. Glenn B . Wiggins is Curator Emeritus in the Department o f Entomology, Royal Ontario Museum, and Professor Emeritus i n the Department o f Zoology, University o f Toronto. The first edition was selected by Choice, a publication o f the Association o f College and Research Libraries, as one of the outstanding academic books of 1978.

This page intentionally left blank

GLENN B. WIGGINS

Larvae of the North American Caddisfly Genera (Trichoptera) 2nd edition

U N I V E R S I T Y OF T O R O N T O Toronto Buffalo London

PRESS

© University o f Toronto Press Incorporated 1996 Toronto Buffalo London Printed in Canada Reprinted 1998, 2000, 2009 I S B N 0-8020-2723-7 (cloth)

Printed on acid-free paper

Canadian Cataloguing in Publication Data Wiggins, Glenn B . Larvae o f the North American caddisfly genera (Trichoptera) 2nd ed. Includes index. I S B N 0-8020-2723-7 1. Caddisflies - Canada. 2. Caddisflies United States. 3. Insects - Larvae. 4. Caddisflies - Identification. 5. Caddisflies Canada - Identification. 6. Caddisflies United States - Identification. I . Title QL517.1.A1W53 1996

595.7'45'0971

C95-932174-8

University o f Toronto Press acknowledges the financial assistance to its publishing program o f the Canada Council and the Ontario Arts Council. University o f Toronto Press acknowledges the financial support for its publishing activities o f the Government o f Canada through the B o o k Publishing Industry Development Program (BPIDP).

This book is dedicated to Professor Herbert H . Ross

I consider i t as o f the utmost importance fully to recognise that the amount of life i n any country, & still more that the number of modified descendants from a common parent, w i l l in chief part depend on the amount of diversification which they have undergone, so as best to f i l l as many & as widely different places as possible i n the great scheme of nature. Charles D a r w i n Charles Darwin's

Natural Selection

(p. 234) ed. R.C. Stauffer 1975

Contents

Preface to the First Edition ix Preface to the Second Edition x i i G E N E R A L

S E C T I O N

Introduction 3 Objectives 4 Geographic limits 5 Organization and methods 5 Use o f keys 7 Classification

Associating larval stages 37 Preserving, storing, and shipping specimens 38 Studying specimens 40

8

Biological considerations 14 Ancestral habitat 14 Habitat diversity 14 Respiration 15 Feeding 19 Construction behaviour 21 Life cycles 22 Morphology 26 Head 26 Thorax 28 Abdomen 30 Techniques 35 Collecting 35

S Y S T E M A T I C

S E C T I O N

Key to larvae of North American families of Trichoptera 43 Suborder Spicipalpia 49 1 Family Glossosomatidae 50 2 Family Hydrobiosidae 67 3 Family Hydroptilidae 71 4 Family Rhyacophilidae 110

5 6 7 8 9 10 11

Suborder Annulipalpia 117 Family Dipseudopsidae 118 Family Ecnomidae 123 Family Hydropsychidae 126 Family Philopotamidae 150 Family Polycentropodidae 159 Family Psychomyiidae 174 Family Xiphocentronidae 185

Suborder Integripalpia 189 12 Family Apataniidae 190 13 Family Beraeidae 203 vii

Contents 14 Family Brachycentridae

206

23 Family Phryganeidae 374

15 Family Calamoceratidae 218

24 Family Rossianidae 399

16 Family Goeridae 226

25 Family Sericostomatidae 404

17 Family Helicopsychidae

237

18 Family Lepidostomatidae 19 Family Leptoceridae

26 Family Uenoidae 413

241

249

Literature cited 427

20 Family Limnephilidae 268 21 Family Molannidae

352

22 F a m i l y Odontoceridae

Taxonomic index 453

359

Addendum for this 2009 reprint edition 1. Several references provided under Literature Cited i n the 1996 and 1998 printings o f this book were listed as I n Press. Final publication citations for these references are provided here: Bowles, D . E . 1995. A new species o f Austrotinodes

(Trichoptera: Ecnomidae) from Texas.

Journal o f the N e w York Entomological Society 103: 155-61 Frania, H.E., and Wiggins, G.B. 1997. Analysis o f morphological and behavioural evidence for the phylogeny and higher classification o f Trichoptera. Royal Ontario Museum, Life Sciences Contributions 160 Gall, W . K . 1994. Phylogenetic studies i n the Limnephiloidea, w i t h a revision o f the w o r l d genera o f Goeridae (Trichoptera). Ph.D. thesis, Department o f Zoology, University o f Toronto [Replacement for Gall, W . K . and Wiggins, G.B.: i n press and i n preparation] Vineyard, R . N . , Wiggins, G.B., Frania, H.E., and Schefter, P.W. 2005. The caddisfly genus Neophylax (Trichoptera: Uenoidae). Royal Ontario Museum, Contributions i n Science 2 Wiggins, G.B. 1998. The caddisfly family Phryganeidae (Trichoptera). University o f Toronto Press W i g g i n g GJB^ d P k r 1997 C d d i f l i (Trichoptera) o f t h Y i i k o n w i t h ly i o f the Holarctic and Beringian species o f N o r t h America. In Insects o f the Yukon, H.V. Danks and J.A. Downes (eds.), pp.787-866. B i o l o g i c a l Survey o f Canada (Terrestrial Arthropods), Ottawa a n

a r

e

.

a

s

e s

e

a n a

s

s

2. Family Hydroptilidae. The larva illustrated and tentatively assigned here to Alisotrichia (3^; p p ^ 0 ^ 1 ) h b q t l y to b d o n g to ly g i d g M ji otrichia Harris and Holzenthal. Formerly considered a species group o f Alisotrichia, this genus is k n o w n from M e x i c o and Guatemala but has not been recorded north o f M e x i c o . w

a

s

s

o

w

n

s u

s e

u e n

a

n

e

w

r e c o

n

z e

e n u s

e

c a n

3. Larvae are u n k n o w n for t w o additional N o r t h American genera not included i n this book: Nothotrichia (Hydroptilidae) and Sisko (Philopotamidae).

viii

Preface to the First Edition

This is a reference w o r k to the identity, structure, and biology of larvae of the North American caddisfly genera. M o r e precisely perhaps, i t is a stage in the evolution of such a reference, for a definitive work even at the generic level is still w e l l beyond the information now available. The book is the result of a project I began some years ago to increase knowledge about larval Trichoptera in N o r t h America. Systematic collections on which it is based were brought together i n the course of more than 150,000 miles o f travel in field expeditions through many parts of Canada and the United States, especially i n the western mountains where the fauna is highly diverse yet little explored. Associations between larval and adult stages were established for some 350 species, approximately 30% of the 1200 or so species o f Trichoptera now k n o w n in the two countries; over 200 o f these were established for the first time. Although the information made available is still far short of enabling one to produce keys for the identification o f North American caddisfly larvae to the species level, it represents a substantial advance at the generic level. Since the genus i n the Trichoptera, as i n most groups, represents an ecological as w e l l as a morphological type, i t provides a useful and an incisive base for generalization. To date, 142 Nearctic genera are recognized and larvae have been identified for all but 6 (4%); diagnostic characters for larvae of 14 genera are given here for the first time, and from this general project characters for an additional 16 genera were originally published elsewhere. Having gained a better understanding o f the range of larval characters covered by most genera, I have been able to establish more precise diagnoses for them and consequently have introduced many new characters into the generic keys. Ultimately, of course, keys for identification o f larval Trichoptera to the species level w i l l provide the most effective aid to workers in freshwater biology, but, i n general, this level o f precision is not possible in North America because sufficient basic data have not yet been assembled. I am conscious o f m y good fortune i n having the support of several institutions and agencies in this project. The Royal Ontario Museum has provided the working facilities for m y studies, and the documented collections on which they are based are part of the research materials of the Department of Entomology. I n the early years of m y field work, IX

Preface to the F i r s t E d i t i o n 1962-68, when intensive surveys were made in the western United States, financial support was received from the National Science Foundation. Operating grants from the National Research Council of Canada have supported the project in recent years. Funds from the Fisheries Research Board of Canada and from the Canadian National Sportsmen's Show have also been received. Substantial grants toward the cost of publishing this book were received from the National Research Council of Canada and the Publications Fund o f the University of Toronto Press. For all of this support I am profoundly grateful. Figures for the book were prepared by M r Anker Odum, until recently the scientific illustrator i n our department. They are sufficient evidence o f M r Odum's

considerable

ability in this field and of his own fascination w i t h insects; I shall add only that I have worked closely w i t h h i m in an attempt to ensure that every drawing conveyed as much accurate morphological information as possible. Individual acknowledgment to all of the persons who have contributed i n some way to this project is not possible here, but I am most grateful for the cooperation, generosity, and encouragement that I have everywhere received. To M r Toshio Yamamoto of our department I owe special gratitude for his knowledgeable and enthusiastic assistance in field work and innumerable other aspects of the project. Several others who were members o f our field expeditions have contributed substantially to the growth of the collections on which the w o r k is based: D . Barr, H.E. Frania, L . H . Kohalmi, B.P. Smith, I . M . Smith, and the late R.S. Scott. Professor Rosemary Mackay of the University of Toronto has been helpful i n resolving ecological matters and problems o f many kinds. It is this sense of community in acquisition and analysis of the collections which underlies use of the pronoun we throughout. M y professional colleagues have responded generously to requests for specimens, information, and comment. It is a pleasure to acknowledge this cooperation from N . H . Anderson, D . G . Denning, O.S. Flint, J.C. Morse, V . H . Resh, H . H . Ross, F. Schmid, S.D. Smith, J.D. Unzicker, and J.B. Wallace. Students i n Aquatic Entomology at the University of Toronto and at the Lake Itasca Biology Sessions o f the University o f Minnesota (1970, 1972, and 1974) helped me to appreciate that keys for identification of insects are too often inconclusive and inadequately illustrated. In affording me opportunities to test earlier versions of the present keys, they also helped to confirm m y suspicion that when effort is invested in producing extensively illustrated keys, learning can be at least easier and is more often exciting. Services made available through the Royal Ontario Museum are invaluable in a w o r k of this kind, and this book represents supporting contributions o f many persons: those involved in the entire museum process leading to deposition of adequately documented specimens in the research collection, secretaries and photographers i n hours of careful w o r k during preparation of the manuscript, and librarians for their efforts to maintain the reference base essential for research in systematics. I wish also to acknowledge the assistance o f J . C E . Riotte for translation of important reference works, Sharon H i c k for compiling the literature citations, Z i l e Zichmanis for art work, and Felix Barlocher for analysis o f larval food. I n acknowledging these contributions, I extend my appreciation to those directors and trustees o f the Royal Ontario Museum whose support my work has had over the years of my curatorial appointment. I hope that they w i l l see in this book another example of the ROM's 'record o f nature through countless ages.' x

Preface to the F i r s t E d i t i o n In matters relating to publication, Lorraine Ourom and Ian Montagnes of the University of Toronto Press have given me advice and encouragement. Facilities for some o f the field work were made available by several institutions: American Museum of Natural History, Southwestern Research Station, Portal, Arizona; University of Minnesota, Lake Itasca Forestry and Biological Station; Oregon State University, Corvallis; Queen's University Biological Station, Chaffeys Locks, Ontario; University o f California Sagehen Creek Research Project, Truckee; University o f Montana Biological Station, Yellow Bay, Flathead Lake; Harkness Research Laboratory, Ontario Ministry o f Natural Resources, Algonquin Provincial Park. M y wife and children shared many o f the longer field expeditions, and more recently contended w i t h my long preoccupation during preparation of the manuscript. I have appreciated their companionship and assistance as well as their forbearance. Finally, I acknowledge a debt to those who have gone before me. Identification of the North American caddisfly larvae was at best uncertain before appearance o f H . H . Ross's Caddis Flies or Trichoptera of Illinois i n 1944, and was again improved at the generic level by his contribution to the revised edition of Ward and Whipple (ed. Edmundson 1959). Taxonomic refinement by Ross, D . G . Denning, F. Schmid, O.S. Flint, and others has continued to develop the classification of the Nearctic Trichoptera into a most useful scientific asset. I n offering the present work as a further step in the evolution of a fundamental faunal reference for larval Trichoptera on this continent, I am mindful that it builds upon the work of others. It is my hope that this book w i l l have some part i n the development o f freshwater biology, bringing nearer the time when the diversity of freshwater communities can be adequately understood, and ultimately preserved. It has been my privilege to explore freshwater habitats over much of North America; i n studying creatures seldom seen by others, I have delighted in sensing the timeless grandeur of natural processes that shaped them as they are. Perhaps this book w i l l also bring to others more of those uniquely human insights that come from seeing and comprehending the life with which we share this planet. G.B.W. March 1976

XI

Preface to the Second Edition

This second edition is an extensive revision of the 1977 book, advancing the information base up to the end of 1993. D u r i n g the interval of 17 years since the manuscript for the 1977 edition was completed, a substantial amount o f new knowledge on North American larval Trichoptera has been published, and advances have been made in classification to reflect new understanding of the phyletic relationships of families and genera. Eight families and 13 genera are added in this revised edition, with a net increase of seven in the number o f North American genera recognized to bring the total to 149; larvae remain unidentifiable for four o f those genera. The number of species recognized i n the North American fauna o f Trichoptera rose to 1340 by the end of 1987 (Wiggins 1990); and i f the rate of increase has averaged about the same at 10 species per year, the total is estimated to have reached approximately 1400 species by the end of 1993. Organization of the families in the systematic section in this revised edition is based on three suborders (Wiggins and Wichard 1989; Frania and Wiggins, inpress),establishing an underlying biological context. Larvae of proven identity continue to be the building blocks for a w o r k of this kind. A number o f these associations have come from our field work since 1977; some have been made available through the work o f others, and are acknowledged at appropriate points i n the book. In organizing new materials and information for the book, I have been aided in many ways by members o f the ROM Department of Entomology. Patricia Schefter has processed large numbers of new accessions for the research collection; and i n her reviews of series o f specimens to test putative diagnostic characters, she has discovered several new character systems. For genera not previously included in the book, new illustrations have been prepared by P.L. Stephens-Bourgeault. Most of the illustrations are those prepared for the first edition by A n k e r Odum, w i t h some others by Clare Storwick and Karl Pogany. The book has been enriched by the contributions of these talented artists, and I am grateful to the Royal Ontario Museum for making possible this assistance. Catherine Rutland has done much to bring about the transformation o f the manuscript for this second edition from the first; Roslyn Darling assisted with word-processing. Throughout the period between the two editions, my w o r k has been supported by an xu

Preface to the S e c o n d E d i t i o n operating grant (A5707) from the Natural Sciences and Engineering Research Council o f Canada. A good deal of new information has been contributed to this revision through research by graduate students supported from the grant: B . D . Beam, H.E. Frania, E.R. Fuller, W . K . Gall, J.D. Kerr, P.W. Schefter, R . N . Vineyard, and N E . Williams. A s i n the first edition, a number of colleagues have provided specimens and information. I t is a pleasure to acknowledge this assistance from N . H . Anderson, L . Boto§aneanu, D . E . Bowles, D . G . Cobb, N . E . Erman, W . L . Fairchild, O.S. Flint, T . M . Green, S.C. Harris, J.G. Irons, D.J. Larson, M . L . Mathis, S.R. M o u l t o n , M . W . Oswood, C.R. Parker, J.S. Richardson, G. Roemhild, D . E . Ruiter, M . W . Sanderson, G.G.E. Scudder, D . H . Smith, K . W . Stewart, J.R. Voshell, W. Wichard, and R.W. Wisseman. I thank editor John St James and staff members o f University o f Toronto Press for their careful work in producing the book. Finally, for much o f the field w o r k related to this second edition, my wife Carol has been both assistant and companion; for that, and for her patience and support during the preparation o f this and other manuscripts, I am grateful. G.B.W. M a r c h 1994

xiii

This page intentionally left blank

GENERAL

SECTION

This page intentionally left blank

Introduction

I n no small way, aquatic insects help to sustain streams, rivers, marshes, and lakes as functional, productive ecosystems; and caddisflies are major components of all of these communities. Caddisflies, or Trichoptera,* are a relatively small order o f insects widely distributed on almost every habitable land mass. Between 9000 and 10,000 species are now k n o w n in the world, but the rate at which species new to science continue to be discovered indicates that the actual world fauna is very much larger ( M a l i c k y 1973, 1993; Schmid 1984). These insects have made little impact on popular attention, probably because most adult caddisflies are small greyish brown, moth-like insects active mainly at night; and also because larval caddisflies live in water, where they are w e l l enough concealed to escape notice by casual observers. Caddisflies, however, are common; and their larvae are usually abundant i n freshwater habitats, which means that these insects are important components of aquatic systems (Wiggins and Mackay 1978). Because caddisflies have evolved by exploiting resources of the full range of freshwater habitats from cold springs, through streams, rivers, ponds, and marshes, to the shorelines and depths o f lakes, and to temporary pools, they contribute to the transfer o f energy and nutrients through the trophic levels of all freshwater systems. This broad diversification underlies both the abundance and the importance of caddisflies i n freshwater biology. Apart from their ecological roles in aquatic communities, caddisflies are themselves remarkable animals. Most biologists are aware that the larvae of these insects build shelters, but few have seen the exquisite seine-like caddis nets fastened in thousands to the rocks o f rivers and streams everywhere; and not many appreciate that the protective tubuThe name Trichoptera is derived from the Greek trichos ('hair') andpteron ('wing'), in reference to the hair covering on the wings of the adults. The origin of caddisfly is obscure, but according to Hickin (1967) it dates in reference to these insects at least to Izaak Walton's Compleat Angler (1653; 'cod-worm or caddis'). In reference to cotton or silk materials, various versions of the word date to 1400; and cadysses appeared in Shakespeare's The Winter's Tale (1611) in this sense. Although connection between the two usages has not been firmly established, Hickin states that itinerant vendors of pieces of cloth fastened bits to their clothing as an advertisement and were called cadice men, suggesting a parallel with the case-making larvae. 3

Introduction lar cases constructed by caddis larvae lead to the use of silk to increase respirational efficiency, enabling caddisflies to exploit the resources of lentic habitats. The variety of structures built by caddis larvae ought to have established them among the most fascinating of all insects; but the diversity i n caddisfly larval behaviour is largely unappreciated. The production o f silk by caddis larvae, and the varied behaviours through which silk is utilized i n constructing different types of cases and retreats, are significant factors broadening the biological diversity of Trichoptera (Mackay and Wiggins 1979). Silk has enhanced the partitioning of habitats and trophic resources by Trichoptera. Consequently, caddisflies are particularly finely tuned as indicators o f perturbations in freshwater ecosystems; and identification of larvae at the species level is a valuable aid in monitoring the health o f those systems (Resh and Unzicker 1975). Aquatic insect larvae are widely used in several aspects of water-quality assessment, and Trichoptera are essential components of those investigations (Resh 1993). Data on pollution tolerance of larval Trichoptera have been compiled by Harris and Lawrence (1978). Since fresh waters are one of the most basic of all natural resources, the communities o f organisms that live w i t h i n them and underlie their productivity and ecological harmony have to be subjects of high priority for scientific study. Even so, freshwater biologists have always had problems i n elucidating the precise ecological roles of insect species i n a community, largely because their larval stages are difficult to identify. Insufficient taxonomic work on the larvae o f caddisflies, and indeed of all aquatic insects, remains a severe barrier to the progress of freshwater biology (Wiggins 1966; Hynes 1970). OBJECTIVES

There is, then, a place for a reference work on North American caddisfly larvae. This book could have taken several forms, but I have organized the information with the needs o f three groups of users in m i n d . For freshwater biologists and ecologists, I have attempted to provide the means for precise identification of families and genera of caddisfly larvae in aquatic communities throughout North America, augmented by some biological information and references to the scientific literature. Identification of larvae to the species level is the ultimate goal, but except for a few o f the smaller families, that goal lies far beyond our present knowledge. For university students concerned w i t h various aspects of aquatic biology, the book is intended to introduce Trichoptera as important components of freshwater communities. Taxonomic diversity in these communities may be itself an object in teaching, or a means to demonstrate ecological principles. I n either case, discovering how many different types of organisms there are i n a freshwater community can be a revealing experience for students; and identification o f the organisms is the key to understanding their role i n the community. I hope that the book w i l l also encourage the use o f caddisfly larvae i n experimental studies of construction behaviour. Thus, for students I have attempted to make generic groups more than disconnected sets of morphological characters, and to make them come alive as whole organisms adapted i n elegant ways to particular niches of the freshwater community. Finally, for systematists, I have tried to produce a reference that would serve as an atlas of gross morphology of the trichopteran larval types in North America. It is well estab4

Introduction lished that data from larval morphology can be critical in assessing systematic relationships of Trichoptera (and other insects), and for advancing hypotheses concerning their phylogeny (Wiggins 1981), but much o f this morphological information is widely dispersed or is not available i n the literature. W i t h i n the constraints of design and space established by the first t w o objectives, compromise is often made in this third one, w i t h the result that illustrations of smaller structures i n many groups have not been included. GEOGRAPHIC

LIMITS

The genera covered are all those currently recognized w i t h i n the Nearctic region, excluding the islands o f the Caribbean. The species totals given for each genus are those k n o w n to occur i n Canada and the United States up to the end o f 1993. I n summaries of global distribution for families and genera, i t w i l l be understood that no Trichoptera are extant i n Antarctica. ORGANIZATION

AND

METHODS

This book is primarily a reference work. Families are grouped i n three suborders, arranged in alphabetical sequence within each one, and numbered consecutively from 1 to 26. W i t h i n each family the genera are arranged alphabetically and numbered consecutively such that the reference number 20.12 specifies Limnephilidae (family no. 20): Dicosmoecus (limnephilid genus no. 12); individual illustrations on each plate are lettered consecutively A, B , etc. A classification o f the North American families, subfamilies, and genera is provided on pp. 8-13. A rather large part of the book is devoted to illustrations because this is the most effective way o f communicating morphological information. Fine distinctions i n form and proportions o f body parts are useful i n identification, and can be best conveyed by illustration. The stylized arrangement of the legs i n the habit figures is made to permit a clear view of the relative lengths of segments and o f setal arrangement. Abdominal gills are drawn to reveal their segmental position. I n the figures of head and thorax, all parts are shown usually i n full dorsal view, although they w o u l d not be seen simultaneously in that relationship in life. Illustrations of cases and retreats are provided i n some number because these structures provide excellent field characters for generic recognition, and also because they rank among the extraordinary constructions o f any animal. The General Section is concerned w i t h various aspects of existing knowledge of the Trichoptera. Biological Considerations is an attempt to place aspects of habitat, respiration, feeding, construction behaviour, and life cycles i n an ecological and evolutionary context. The structure of caddisfly larvae is considered in the chapter on Morphology. Under Techniques are discussed methods of collecting, rearing, preserving, and studying larval specimens. Illustrations in the General Section are designated by Roman numerals. I n the Systematic Section, the key to families includes all those now recognized in the Nearctic region. General features of each family are outlined under the family heading; the genera in each family are arranged alphabetically, but an indication o f the broad relationships among genera can be obtained from the groupings i n subfamilies or tribes. For each genus a summary o f essential features is provided. Under Distribution and Species is given 5

Introduction the general world distribution of the genus; distribution i n North America is based on literature records compiled for an Annotated Catalogue of the Trichoptera of North America North of Mexico (Wiggins and Flint, in prep.), which includes some records from the ROM collection not published previously. The number o f species known i n Canada and the United States is provided, but in many genera these totals w i l l be increased as more faunal exploration is done. Literature references are given for larval diagnoses and descriptions at the species level. B y indicating for each genus the number of species known as larvae, both in the literature and i n our collections, I have shown the base on which the present generic diagnoses rest. In many genera this base represents only a small part of the total number of species known, and users o f this book should be aware that larvae yet to be discovered may render some o f the diagnoses inadequate for particular genera. Information summarized for each genus under Morphology pertains largely to features diagnostic for the genus, or to general features that would help to confirm an identification made by using the keys. The length given for the larva is usually that of the largest specimen examined, or occasionally o f one recorded i n the literature; the measurement is a straight line on the long axis o f the body from the anterior margin of the head, usually as positioned in the habit figures of larvae, to the posterior edge of the anal proleg but does not include protruding setae. The larva illustrated is not necessarily the largest one examined, but i n almost all genera, the larva illustrated is a final instar. Magnifications given i n the figure captions for habit drawings o f larvae i n most families are based on a straightline measurement of the entire larva, as indicated above; but in the families of the A n n u l i palpia, where preserved larvae are usually strongly curved and difficult to measure, the magnification is based on length of the head capsule from the posterior margin to the anterior border of the frontoclypeal apotome, excluding labrum and mandibles. Under Case, or Retreat for those groups in which the larval structure is fixed in one place, are outlined essential features o f these larval constructions. Illustrations of portable cases include an end-on view o f the posterior end of the case, an important functional and diagnostic feature of case-making behaviour. The case length given is the m a x i m u m i n material I have studied or for specimens recorded in the literature. Generic data summarized under Biology are drawn from our collections and field observations, supplemented wherever possible by pertinent literature references; these and other references should always be consulted for additional information because I have made only summary statements. Food studies by others have been cited whenever available, but for many genera there is no information on food i n the literature. For some o f these, temporary slide mounts o f the entire gut content were prepared, and examined under magnifications up to 400x. Visual estimates were made of proportions o f components on the slide; usually the guts of three larvae were examined, the number of specimens expressed i n parentheses i n the text. It is m y intention only to provide the basis for some statement o f items ingested where none was available previously; no illusion is held concerning the quantitative and seasonal basis o f the samples. Comments under Remarks often include references to important taxonomic reviews o f adult stages of North American species in the genus under consideration because these sources might not be known to many users o f this book, but could be useful i f adults were associated w i t h larvae. Where no reference is given to works dealing w i t h taxonomy of the adults, either under this heading or elsewhere, it can be assumed that the most useful 6

Introduction general review for that genus is still to be found i n the classic Caddis Flies, or Trichoptera, of Illinois by H . H . Ross (1944). Taxonomic and nomenclatorial designations are not cited in this work; most w i l l be found i n the Triehopterorum Catalogus, o f which 15 volumes have been published (Fischer 1960-73). The taxonomic index to the present work lists all genera and higher taxa mentioned, and includes synonyms established since 1944. USE OF K E Y S The keys and diagnostic characters in this book are based on final instars; some diagnostic characters may be effective for later subterminal instars but others are not, especially those relating to setae and gills, which can change at each instar. As a general principle, diagnosis of subterminal instars is not possible for larval Trichoptera. Recognition o f final instars improves with experience. Subterminal instars tend to have cases or retreats of flimsy construction; pieces of plant or mineral material are easily separated, probably because of economy in the amount of silk protein invested i n structures that have relatively short-term use. Early instar larvae have a juvenile appearance; gills and setae are often short and sparse, and sclerotized areas are more pliable than in larvae that are fully developed. I f in a series o f larvae collected at one site, the specimens appear to be generally similar to one another but differ in size, the largest larvae should be identified first; and i f the smaller specimens give difficulty w i t h the keys, the possibility can be considered that they are early stages of the larger larvae and therefore inappropriate for any keys. I n general, users are encouraged to cultivate an approach to identification w i t h keys that avoids investing time in young larvae for which no diagnoses exist. I f their identity is important, i t is more effective to return to the site at a later date and obtain fully developed larvae. Larval stages are k n o w n for a fraction of the species i n many genera, and larvae not yet known, when identified, w i l l undoubtedly reveal some of the generic diagnoses to be imprecise. Larvae i n four genera have yet to be discovered; these deficiencies are specified i n the general sections treating the families concerned and may, when known, affect the accuracy o f diagnoses for related genera. Larval associations for a few genera are proposed tentatively on the basis of circumstantial evidence, but the qualifications are stated in the generic section. I n making generic identifications w i t h this book, users who do not recognize the families of Trichoptera at sight should first identify specimens w i t h the key to families; the general outline for a family should be used to corroborate placement made through the key, and the appropriate key to genera can then be entered with assurance. A t the level o f both family and genus, reliance on the illustrations alone w i l l lead to misidentification because the plates do not necessarily include every condition of a character represented w i t h i n a group. The keys are designed to eliminate sequentially taxa that share certain distinctive characters; the text summary for each genus deals with supporting characters and should be consulted. Corroboration o f determinations from distributional information should always be sought. A key to pupae o f North American families o f Trichoptera is available elsewhere ( W i g gins 1984a). Generic keys are available to pupae i n a few families (Ross 1944). 7

Classification

Three suborders and six superfamilies are recognized here in the Trichoptera, in accordance w i t h phylogenetic evidence and proposals outlined at length by Frania and Wiggins (in press).A higher classification o f three superfamilies - Rhyacophiloidea, Hydropsychoidea, and Limnephiloidea - was employed by Ross (1956, 1967) and is widely used elsewhere, including the first edition of this book. The three suborders employed here Spicipalpia, Annulipalpia, and Integripalpia - are equivalent to the three superfamilies of Ross (1956), but are based on independent phylogenetic analysis of much new evidence (Frania and Wiggins,inpress).The superfamilies used here are in accordance with the groups of Frania and Wiggins Cm press) and Gall and Wiggins (in press). Grouping by tribe is outlined under the family heading as appropriate. The classification for North American genera employed in this book is outlined below. Genera for which larval stages are unknown are marked w i t h an asterisk.*

S P I C I P A L P I A (Closed-cocoon makers) Rhyacophilidae Himalopsyche Banks Rhyacophila Pictet

8

Principal reference p. 49 p. 110 4.1 4.2

Hydrobiosidae Atopsyche Banks

p. 67 2.1

Hydroptilidae Subfamily Ptilocolepinae Palaeagapetus Ulmer

p. 71 p. 73 3.13

Subfamily Hydroptilinae Agraylea Curtis Alisotrichia Flint Dibusa Ross

p. 73 3.1 3.2 3.3

Classification Hydroptila Daim an Ithytrichia Eaton Leucotrichia Mosely May atrichia Mosely Metrichia Ross Neotrichia M o r t o n Ochrotrichia Mosely Orthotrichia Eaton Oxyethira Eaton Paucicalcaria Mathis & Bowles Stactobiella Marty no v Zumatrichia Mosely Glossosomatidae Subfamily Glossosomatinae Anagapetus

Ross

Glossosoma

Curtis

Subfamily Agapetinae Agapetus

Curtis

Subfamily Protoptilinae Culoptila Mosely Matrioptila Ross Protoptila Banks

3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.14 3.15 3.16 p. 50 p. 51 1.2 1.4 p. 51 1.1 p. 52 1.3 1.5 1.6

A N N U L I P A L P I A (Fixed-retreat makers) Philopotamoidea Philopotamidae Subfamily Philopotaminae Dolophilodes Ulmer Wormaldia McLachlan

p. 117

Subfamily Chimarrinae

p. 151

Chimarra

Stephens

Hydropsychoidea Psychomyiidae Subfamily Psychomyiinae hype McLachlan Psychomyia Latreille Tinodes Curtis Subfamily Paduniellinae Paduniella Ulmer Xiphocentronidae Xiphocentron

Brauer

p. 150 p. 151 8.2 8.3

8.1

p. 174 p. 174 10.1 10.3 10.4 p. 174 10.2 p. 185 11.1

9

Classification Cnodocentron Dipseudopsidae Phylocentropus Ecnomidae Austrotinodes

Schmid*

p. 185

Banks

p. 118 5.1

Schmid

Polycentropodidae Subfamily Polycentropodinae Cernotina Ross Cymelius Banks Neureclipsis McLachlan Nyctiophylax Brauer Polycentropus Curtis Polyplectropus Ulmer

p. 159 p. 160

Hydropsychidae Subfamily Arctopsychinae Arctopsyche McLachlan Parapsyche Bette n

p. 126 p. 127 7.1

Subfamily Diplectroninae Diplectrona Westwood Homoplectra Ross Owpsyche Ross* Subfamily

Hydropsychinae

Cheumatopsyche Wallengren Hydropsyche Pictet Pot amy ia Banks Smicridea McLachlan Subfamily Macronematinae Leptonema Guerin-Meneville Macro sternum Kolenati I N T E G R I P A L P I A (Portable-case makers) Phryganeoidea Phryganeidae Subfamily Yphriinae YphriaMilm Subfamily Phryganeinae Agrypnia Curtis Banksiola Martynov Beothukus Wiggins Fabria M i l n e Hagenella Martynov 10

p. 123 6.1

9.1 9.2 9.3 9.4 9.5 9.6

7.8 p. 127 7.3 7.4 p. 128 p. 128 7.2 7.5 7.9 7.10 p. 128 7.6 7.7 p. 189 p. 374 p. 375 23.10 p. 375 23.1 23.2 23.3 23.4 23.5

Classification Oligostomis Kolenati Oligotricha Rambur Phryganea Linnaeus Ptilostomis Kolenati Limnephiloidea Braehycentridae Adicrophleps Flint Amiocentrus Ross Brachycentrus Curtis Eobrachycentrus Wiggins M ic ras etna McLachlan Lepidostomatidae Subfamily Lepidostomatinae Lepidosioma Rambur Subfamily Theliopsychinae Theliopsyche Rossianidae Goereilla Rossiana

Banks

Denning Denning

Limnephilidae Subfamily Dicosmoecinae Allocosmoecus Banks Amphicosmoecus Schmid Cryptochia Ross Dicosmoecus McLachlan Ecdisocosmoecus Schmid Ecclisomyia Banks Eocosmoecus Wiggins & Richardson Ironoquia Banks Onocosmoecus Banks

23.6 23.7 23.8 23.9

p. 206 14.1 14.2 14.3 14.4 14.5 p. 241 p. 242 18.1 p. 242 18.2 p. 399 24.1 24.2 p. 268 p. 269 20.1 20.2 20.10 20.12 20.13 20.14 20.15 20.24 20.28

Subfamily Pseudostenophylacinae Pseudostenophylax Martynov

p. 270 20.33

Subfamily Limnephilinae Anabolia Stephens Arctopora Thomson Asynarchus McLachlan Chilostigma McLachlan Chilostigmodes Martynov* Chyranda Ross Clistoronia Banks Clostoeca Banks Desmona Denning

p. 270 20.3 20.4 20.5 20.6 p. 271 20.7 20.8 20.9 20.11 11

Classification F renés ia Betten & Mosely

Glyphopsyche B anks Grammotaulius Kolenati Grensia Ross Halesochila Banks Hesperophylax Banks Homophy lax Banks Hydatophylax Wallengren Lenarchus M a r t y n o v Leptophylax Banks* Limnephilus Leach Nemotaulius Banks Phanocelia Banks Philarctus McLachlan Philocasca Ross

Platycentropus Ulmer Psychoglypha Ross Psychoronia Banks Pycnopsyche Banks Sphagnophylax Wiggins & Winchester

Apataniidae Allomyia Banks Apatania Kolenati Manophylax Wiggins Moselyana Denning Pedomoecus

Ross

Uenoidae Subfamily Uenoinae Farula M i l n e Neothremma Dodds & H i saw Sericostriata Wiggins, Weaver & Unzicker Subfamily Thremmatinae Neophylax McLachlan Oligophlebodes Ulmer Goeridae Subfamily Goerinae Goera Stephens Goeracea Denning Goerita Ross Subfamily Lepaniinae Lepania

12

Ross

20.16 20.17 20.18 20.19 20.20 20.21 20.22 20.23 20.25 p. 271 20.26 20.27 20.29 20.30 20.31 20.32 20.34 20.35 20.36 20.37 p. 190 12.1 12.2 12.3 12.4 12.5 p. 413 p. 413 26.1 26.3 26.5 p. 414 26.2 26.4 p. 226 p. 226 16.1 16.2 16.3 p. 226 16.4

Classification Leptoceroidea Leptoceridae Subfamily Leptocerinae Ceraclea Stephens Leptocerus Leach

Mystacides Berthold Nectopsyche M u l l e r Oecetis McLachlan Setodes Rambur Triaenodes McLachlan Ylodes M i l n e

p. 249 p. 250 19.1 19.2 19.3 19.4 19.5 19.6 19.7 19.8

Molannidae Molanna Curtis Molannodes McLachlan

p. 352 21.1 21.2

Calamoceratidae Anisocentropus McLachlan Heteroplectron McLachlan Phylloicus M u l l e r

p. 218 15.1 15.2 15.3

Odontoceridae Subfamily Odontocerinae Marilia M u l l e r Namamyia Banks

p. 359 p. 360 22.1 22.2

Nerophilus Banks Parthina Denning Psilotreta Banks

Subfamily Pseudogoerinae Pseudogoera Carpenter Sericostomatoidea Sericostomatidae

22.3 22.4 22.6 p. 360 22.5

p. 404

Agarodes B anks Fattigia Ross & Wallace Gumaga Tsuda

25.1 25.2 25.3

Beraeidae Beraea Stephens

p. 203 13.1

Helicopsychidae Helicopsyche

p. 237 17.1

von Siebold

13

Biological Considerations

ANCESTRAL

HABITAT

A l l three subordinal groups o f Trichoptera are represented in cool, running waters (Fig. I ) . I n families represented i n both lotie and lentic waters, the genera w i t h more primitive morphological character states occur i n cool, lotie habitats, and those w i t h derived states occur in wanner lentic sites (Ross 1956). The closed cocoons of spicipalpian families represent ancestral construction behaviour shared w i t h primitive Lepidoptera (Wiggins and Wichard 1989). From the preponderance of Spicipalpia in running waters, it is inferred that these families are physiologically constrained to cool, lotie waters, where respiration of the pupae is sustained solely by the diffusion of oxygen across the osmotically semipermeable wall of the cocoon. O f the four families in the Spicipalpia, the Rhyacophilidae, Hydrobiosidae, and Glossosomatidae occur in flowing water; a few genera of the Hydroptilidae occur in lentic sites of lakes, but most genera, including the primitive members o f that family, are confined to running waters. Accordingly, cool, lotie waters are inferred to be the ancestral habitat in which progenitors of the Trichoptera first became aquatic, and the habitat in which differentiation into the subordinal groups probably occurred. These groups represent essentially different methods o f l i v i n g and feeding by larvae, and it is likely that their differences evolved as innovations for exploiting available niches in lotie habitats. A common observation is that apart from Diptera, the Trichoptera are usually more numerous i n species and more diverse biologically in a given lotie habitat than are other aquatic insect orders; this is an indication o f the effectiveness of basic ecological diversification i n the Trichoptera ( W i g gins and Mackay 1978). Utilization o f silk by caddisfly larvae for construction was undoubtedly an asset i n their ecological diversification because silk adds, i n effect, a whole new dimension to behavioural evolution; the situation is analogous to the role o f silk i n the ecological diversification o f spiders. HABITAT

DIVERSITY

It w i l l be seen from Figure l that North American families of Trichoptera differ markedly 14

B i o l o g i c a l Considerations in the ability of their members to exploit warm, lentic habitats: thus, all 26 North A m e r i can caddisfly families (100%) are represented in cool, running waters; 21 (81%) i n warm, lotie sites; 8 (31%) in standing waters of lakes and marshes, excluding those lotic-dwelling families whose larvae also live along wave-washed shores of lakes (i.e. Glossosomatidae, Hydropsychidae, Sericostomatidae, and Helicopsychidae); and only 3 families (11%) in temporary pools, a habitat that for caddisfly larvae is a more constraining extension o f permanent, lentic waters. We see then that representatives from all three subordinal groups o f Trichoptera have invaded lentic waters independently, and that certain of the Integripalpia and Annulipalpia have further succeeded i n colonizing temporary pools. I n Figure I the gaps between habitat categories represent zones o f intergrading conditions. Therefore, this series of habitat types grades through decreasing water currents and increasing water temperatures; current is critical in shortening the diffusion path by which oxygen becomes available for respiration by caddis larvae (Jaag and A m b u h l 1964). Consequently, the general trend of the series of habitat types i n Figure I indicates increasing selection for greater respirational efficiency. I f enhanced respirational efficiency is one of the requirements for caddisfly larvae l i v i n g in lentic waters, i t can hardly be coincidence that in five of the eight families represented i n lentic waters, the larvae are portable-case makers: Leptoceridae, Molannidae, Phryganeidae, Limnephilidae, and Lepidostomatidae. The exceptions are the Dipseudopsidae, Polycentropodidae, and Hydroptilidae; and larvae of lentic-dwelling genera i n each of these families construct tubular retreats or cases which the larva ventilates (see below). RESPIRATION

The idea that the portable tube-case of Trichoptera enhances respiratory efficiency has been shared by students of these insects at least since Dodds and Hisaw (1924) and M i l n e (1938), and possibly others before them. The principle is that dorsoventral abdominal undulation or ventilation by the larva brings a current of water through the anterior opening and out the posterior opening, a flow that can be detected readily by an observer (Fig. I I ) ; thus abdomen and gills are bathed i n a current o f continually renewed water. The tubular case serves then as a conduit for a channelled flow of water, enabling the larva to control its o w n current. I n accordance w i t h this hypothesis, the three humps o f abdominal segment I are believed to maintain a space between the larva and the sides of the case, allowing the respiratory current access to all sides o f the abdomen. It should be added here that at least some larvae can reverse the direction of water flow (Tindall 1963; M e r r i l l and Wiggins 1971). Supporting evidence for the respiratory advantage of the tube-case has come from several sources. Jaag and A m b u h l (1964) found that larvae of the limnephilid genus Anabolia, when inside their cases, were able to survive at lower oxygen concentrations than those without cases because they were able to remove more oxygen from the water. Several workers have shown that a rise i n temperature or a decrease in dissolved oxygen results in an increased rate and amplitude of ventilatory movement by case-bearing caddisfly larvae (Van D a m 1938; Fox and Sidney 1953); Feldmeth (1970) found that in t w o species o f Pycnopsyche the rate of ventilation increased as current speed decreased, indicating that abdominal ventilation compensates for l o w current velocity. Philipson (1954) 15

B i o l o g i c a l Considerations Cool lotie

Warm lotie 1

Lentic

Temporary pools I i i i i

SPICIPALPIA (closed-cocoon makers)

i i i i

I i I i i

Glossosomatidae Hydrobiosidae Hydroptilidae Rhyacophilidae

i

i

I

i i i i

i i i i

i

i i i i i

ANNULIPALPIA (fixed-retreat makers)

i

Dipseudopsidae Ecnomidae Hydropsychidae

i

Philopotamidae Polycentropodidae Psychomyiidae Xiphocentronidae

i

(portable-case makers) Apataniidae Beraeidae Brachycentridae Calamoceratidae Goeridae Helicopsychidae Lepidostomatidae Leptoceridae Limnephilidae Molannidae Odontoceridae Phryganeidae Rossianidae Sericostomatidae Uenoidae Decreasing current and 0

I 16

i i

i

i

i

i

i

i i

i i i i i

i i i i i

i

i

i

i

i

I

i i

INTEGRIPALPIA

i i

••••••

' i

2

1

1

!

'

i

i

i

i

i

i

i

i

i

i

availability, increasing temperature

Habitat diversity in families of North American Trichoptera

— ~

B i o l o g i c a l Considerations

I I Circulation of water generated by abdominal ventilation through case of typical case-making caddis larva demonstrated that the frequency of ventilation movements i n Hydropsyche instabilis and Polycentropus flavomaculatus decreased w i t h increasing current. Larvae o f rheophilic genera such as Rhyacophila and Wormaldia do not normally ventilate by abdominal movements (Philipson 1954), although under respiratory duress larvae of these two families and of the Glossosomatidae are said to ventilate (Tomaszewski 1973). Measurement of oxygen uptake by larvae w i t h cases and deprived of their cases by Williams et al. (1987) showed that the case seemed to aid respiration i n species o f seven families because the rate of respiration was lower and less variable when the larva was i n its case, or the case enabled the larva to tolerate lower levels of oxygen before dying. Larvae o f two species, Helicopsyche borealis (Helicopsychidae) and Phryganea cinerea (Phryganeidae), consumed more oxygen in the case than they did without a case. For larvae of a third group, all belonging to the Limnephilidae, the case seemed to make little difference because oxygen consumption was the same w i t h or without the case. Other species of both the Limnephilidae and Phryganeidae were represented in the first group of seven families where the case was an asset i n respiration. Taken all together, these lines of evidence indicate that the most rheophilic caddis larvae are dependent upon stream current for renewal of freshly oxygenated water, and less rheophilic larvae, primarily Integripalpia, can create or control their o w n current by 17

Biological Considerations abdominal ventilation w i t h i n their portable cases at rates geared to acquire the necessary oxygen with the lowest energy expenditure. Whether all larvae conform to this pattern remains conjectural. Under experimental conditions larvae o f Oligotricha (Phryganeidae), Anabolia and Halesus (Limnephilidae) can survive and develop without cases for several weeks (Majecki and Tomaszewski 1991). Some lentic limnephilid species have been observed to abandon their case at l o w oxygen concentrations (Otto 1976, 1983). Interpretation of observations on the respirational efficiency o f caddis larvae must take account also o f the role o f cases i n protection against predators; efficiency o f respiration within the case may be compromised by the need for the protection of portable cases, w i t h the balance measured by survival i n nature. Moreover, little is known about the respiratory requirements of pupae. Although the Annulipalpia are mainly rheophilic, some members o f the Polycentropodidae are tolerant o f lentic waters (Fig. I ) . Some species o f Polycentropus, for example, live on lake bottoms where there are chironomid larvae that possess haemoglobin as a respiratory asset; and some Polycentropus live in temporary pools, where larvae make a fixed tubular retreat o f silk (Fig. 9.5G) which they ventilate by abdominal undulation (Wiggins 1973a). Larvae o f Dipseudopsidae (Phylocentropus) construct extensive systems of tubes (Fig. 5 . I D ) i n sandy substrates o f streams and lakes, and generate a current through the tube. Since larvae o f a few Hydroptilidae (Spicipalpia) occur in lentic waters and ventilate i n the normal way, it is clear that the hydroptilid purse-case w i t h its apical slits can serve also as an effective tubular conduit for a respiratory current. A m o n g Nearctic hydroptilids, species o f Oxyethira probably occupy the most lentic habitats; their cases are not the typical purse w i t h slits, but a derivative flattened flask o f silk w i t h openings confined to front and rear (Fig. 3.12F). One may wonder to what extent the ability o f these larvae to exploit lentic waters is correlated w i t h more tube-like constructions. Even though these families differ biologically i n many ways, the means by which their members have adapted to lentic waters are similar i n principle; thus, the basic caddisfly larval tube, either portable or fixed, can be regarded as a device that for some and perhaps most families has increased respirational efficiency, thereby helping to open lentic habitats to exploitation by these insects. I t is altogether remarkable that an increase i n respirational efficiency has been achieved as a consequence o f silk production. Notwithstanding a role i n respiration, the portable cases constructed by larval T r i choptera probably served initially to protect and conceal larvae from predators. This seems self-evident because most caddis larvae that graze on diatoms and fine particulate matter on the upper exposed surfaces of rocks i n flowing waters construct portable cases or fixed tubes. Larvae feeding on coarse detritus such as leaves w o u l d be exposed to predators as they moved to areas o f slower current where these materials are usually deposited, and w o u l d benefit from the protection of a portable case. One w o u l d expect that some selective advantage for l i v i n g i n depositional areas would accrue to lotie larvae with more efficient respiration; thus, the portable case that initially afforded protection could have served a second role i n enhancing respiration. W i t h the means to enhance respiration independently o f stream current, case-making Integripalpia could have exploited standingwater systems. Consequently, the t w o competing hypotheses proposed to explain the function and evolution o f portable cases i n Trichoptera (e.g. Williams et al. 1987) need not be 18

B i o l o g i c a l Considerations contradictory. Protection of larvae from predators can be granted a primary role for portable cases; enhancement of respiratory efficiency would have followed as a further evolutionary dividend from the case, and seems to have been an asset in exploiting standing waters. FEEDING

A m o n g the Spicipalpia, most larvae o f the free-living Rhyacophilidae and Hydrobiosidae are predators, but not entirely so for some Rhyacophila are herbivorous (Thut 1969). The flat-bottomed, tortoise-like, portable cases o f the highly rheophilic Glossosomatidae cover the larvae entirely as they graze diatoms and fine organic particles on the exposed upper surfaces o f rocks. A l l three thoracic legs i n glossosomatid larvae are approximately the same size (Fig. 1 .4A), as they are i n the Rhyacophilidae and i n the Annulipalpia, a condition that can be considered part of the trichopteran ground-plan. But i n some of the Hydroptilidae and i n all of the Integripalpia, the legs are progressively longer from front to rear; and except for highly specialized swimmers such as Leptocerus, these larvae are generally adept at walking w i t h the last t w o pairs o f legs (Tomaszewski 1973). Therefore, for feeding, the significance of portable cases - of tortoise, purse, or tube design - is that larvae are able to move actively i n search of energy resources. M a n y of the Hydroptilidae became specialized for feeding on filamentous algae, although a few groups feed on periphyton and fine organic particles. In the Integripalpia, development o f respirational independence probably has allowed the exploitation o f food unrelated to current. M a n y genera, particularly i n the L i m n e p h i l idae and Lepidostomatidae, became largely dependent on dead plant materials such as leaves and wood fragments which support growths o f fungi and bacteria; the micro-organisms have much to do w i t h the palatability and nutrient value of these materials (e.g. Barlocher and Kendrick 1973, 1975). Larvae feeding i n this way are shredders (Cummins 1973), fulfilling one o f the most important ecological roles i n fresh waters, for i n this manner leaves and other large pieces of plant materials are reduced to the fine organic particles utilized by collectors. A few of the Integripalpia - some Phryganeidae, Oecetis, and Ceraclea - became predators; some became diatom feeders as i n the Apataniidae, Uenoidae, and Goeridae. Information available to date suggests that omnivorous feeding is the general condition for larvae i n most families of the Integripalpia. Larvae of the net-spinning Annulipalpia (Philopotamidae, Hydropsychidae, and some Polycentropodidae) build a fixed retreat in which the larva lies while food particles of appropriate size are collected from the current by its silken capture net. I n a functional sense, these retreat-makers are filter feeders (Cummins 1973), and their food includes small fragments of plant and animal materials, faeces of other invertebrates w i t h associated fungi and bacteria, algae, and in some instances other invertebrates. Food of the Philopotamidae is very fine particulate materials; larvae of some genera of the Polycentropodidae are highly predacious. I n the Psychomyiidae, Xiphocentronidae, and Ecnomidae, detrital particles, associated microflora, and algae are also collected, but largely from the substrate surface. These aspects of feeding are summarized in Table 1, based on, but amplifying for T r i choptera, the classification o f trophic categories for aquatic insects developed by C u m 19

B i o l o g i c a l Considerations TABLE 1 Classification of trophic categories for North American Trichoptera (based on Cummins 1973) Method of feeding

Dominant food

North American Trichoptera

Shredders

Herbivores feeding on living vascular hydrophytes and filamentous algae

Brachycentridae (Eobrachycentrus, Micrasema) Hydroptilidae (Hydroptilinae) Leptoceridae (Triaenodes) Phryganeidae

Detritivores feeding on pieces of decomposing vascular plant tissue and associated microflora

Beraeidae Calamoceratidae Lepidostomatidae Limnephilidae Odontoceridae Phryganeidae Sericostomatidae

Filter or suspension feeders

Detritivoreherbivores feeding on fine organic particles and living algal cells

Brachycentridae (Brachycentrus) Dipseudopsidae Hydropsychidae Philopotamidae Polycentropodidae (Neureclipsis)

Substrate surface feeders

As above

Brachycentridae Leptoceridae Psychomyiidae

Scrapers

Herbivoredetritivores feeding on periphyton and fine organic particles

Glossosomatidae Helicopsychidae Hydroptilidae (Leucotrichia) Leptoceridae Apataniidae Goeridae Molannidae Limnephilidae (Dicosmoecinae)

Predators

Carnivores feeding on whole animals or large parts

Hydropsychidae Leptoceridae (Ceraclea, Oecetis) Molannidae Phryganeidae Polycentropodidae {Nyctiophylax, Polycentropus) Rhyacophilidae

Collectors

20

B i o l o g i c a l Considerations mins (1973). This must be seen only as an overview; several families appear in more than one category on the basis o f different genera, although the generic examples listed are not complete for a given family. The food of some species changes seasonally or as the larvae grow larger; Banksiola crotchi became almost totally predacious in the final instar after feeding on detrital materials up to that point (Winterbourn 1971b). Probably because they are limited by small physical size, early instars in all trophic groups feed on fine particulate organic matter. Analyses of food ingested by larval Trichoptera reveal a strong tendency for opportunistic feeding w i t h i n single species; one example is the finding by Cummins (1973) that larvae o f Glossosoma nigrior fed largely on periphyton in a Pennsylvania stream but on detritus in a Michigan stream. Trophic generalism is, in fact, the pattern of feeding by aquatic insect larvae over all (Cummins 1973). For Trichoptera, the central point emerges that, in evolution leading to marked divergence in ways o f obtaining food, there has been little restrictive specialization in the kind of food that can be utilized. CONSTRUCTION

BEHAVIOUR

Retreats and cases are constructed by larvae in some groups of beetles and moths, but the diversity of these structures is much greater in the Trichoptera than i n any other order o f insects. Trichoptera are favourable subjects for studying behaviour because they provide a tangible record o f what they do; analysis of construction behaviour i n the Trichoptera on a detailed level has been undertaken by several workers, such as Hanna (1960) and Hansell (1972, 1974). Although the cases and retreats built by larval caddisflies are extremely important i n respiration and feeding, consideration of their structural details in relation to micro-habitat is illuminating i n other respects. For the most part these structures are lined with silk, and plant and rock pieces are incorporated on the outside. But one can find examples of ways i n which this basic behaviour has evolved to solve many engineering problems: streamlining, ballast, buoyancy, structural rigidity, camouflage, internal water circulation, external water resistance, regulation o f mesh size in nets to obtain an effective compromise between current speed and fine-particle filtering, protection from predators that w o u l d swallow the case and from those that w o u l d intrude, and so on. Solutions to some of these problems in relation to rapid currents were explored by Dodds and Hisaw (1925); comments on others are offered i n appropriate places i n the systematic part of the present work. A g a i n , the significance of silk production in increasing the diversity of solutions, and hence o f niches exploited, is clear. Construction o f retreats, often integrated w i t h silken filter nets, has contributed to the ecological, and hence taxonomic, diversification o f the Annulipalpia (see, e.g., Wallace 1975a, b; Wallace and Malas 1976b). Although the Integripalpia reveal considerably more taxonomic diversity than do the Annulipalpia, the contribution of different sorts of portable cases as factors underlying ecological and taxonomic diversity i n this group is scarcely understood (e.g. Wiggins 1984b). The ability o f caddisfly larvae to recognize and re-enter their own cases was found by M e r r i l l (1969) to differ considerably in several families of Integripalpia; she also found that sensors on the anal claws are important in regulating the m a x i m u m length to which a case is built ( M e r r i l l 1965). The idea, often repeated, that caddisfly species can be distinguished by the cases they 21

B i o l o g i c a l Considerations build has only slight support. By and large, case architecture is characteristic at the generic level. I f in a particular area a genus is represented by only one species, the case is likely to be o f diagnostic value; but where several congeneric species are sympatric, case types are generally not diagnostic for the species. Pupation, the final phase o f aquatic existence in the life cycle, introduces a new set of environmental problems. For the most part, these problems represent compromises between protection of the resting pupa from predators, and sufficient exposure o f the pupa to oxygenating currents of water for respiration. Again, the problems have been met by different ways of using silk to construct pupal enclosures and cocoons (Wiggins and Wichard 1989; Wichard 1991 ; Frania and Wiggins, in press). LIFE

C Y C L E S

Most caddisflies i n temperate latitudes complete one generation each year, passing through the egg, five larval instars, a pupal stage, and a winged adult stage; the time required for completion o f the actual metamorphosis - that is, from separation of the larval cuticle to eclosion or emergence of the adult from the pupal integument - is approximately three weeks. This is the generalized condition, characterized by uninterrupted development. In distinction from many other biological characteristics o f Trichoptera, most of the modifications imposed on this generalized condition are a feature of the species rather than the genus. A life cycle o f six larval instars was recorded for a European species of Sericostoma (Elliott 1969) and o f seven for a European Agapetus (Nielsen 1942); larvae of Gumaga nigricula studied in California moulted up to 14 times during their development (Resh e t a l . 1981). Some modifications to the generalized condition arise through intervention of diapause - a suspension of normal development at some stage in the life cycle until initiated again in response to an external environmental stimulus. Diapause is distinguished from simple quiescence, in which development merely slows during adverse, usually cold, periods to be resumed when conditions again become favourable. For Trichoptera, diapause functions as for other insects by suspending development until conditions in a habitat are more favourable, and also by synchronizing adult emergence after dissimilar periods of larval development. In the family Limnephilidae diapause occurs i n both larval and adult stages (e.g. Denis 1978). Diapause was demonstrated i n the last larval instar of the European limnephilid species Anabolla furcata (Novak 1960): larvae were fully grown in June, fastened their cases to the substrate, and ceased feeding. Experiments revealed that diapause was terminated by short daily photoperiods, similar to those occurring naturally in late summer. Pupation occurred i n nature i n September, adult emergence commencing toward the end of that month. Some influence was also attributed to temperature in termination of the diapause, w i t h temperatures lower than 2 0 ° C hastening termination; adults were found to emerge earlier at higher elevations than those o f the same species at lower elevations. Novak suggested that diapause i n the last larval instar was a general condition for univoltine autumnal Trichoptera. One, and perhaps the principal, advantage o f autumnal reproduction is that larvae feeding on fallen leaves of deciduous trees have a particularly rich food resource in autumn and early winter; larval development completed i n winter or early 22

B i o l o g i c a l Considerations spring must then be suspended until autumn approaches again. The same principle probably holds for the Nearctic limnephilid genus Pycnopsyche; although diapause has not been demonstrated, inactivity of final-instar larvae for periods up to six months, followed by initiation o f metamorphosis during the decreasing daily photoperiods o f late summer (Cummins 1964; Mackay 1972), suggests that diapause is operating as i n Anabolia furcat a.

Similarly, larval feeding and growth in most species o f Neophylax are completed i n spring or early summer, when larvae fasten their cases firmly to the substrate and seal off the entrance. Larvae remain within the case for several weeks, and metamorphosis occurs in late summer followed shortly after by adult emergence (Beam and Wiggins 1987). Most species of the limnephilid genus Dicosmoecus show a similar pattern (Wiggins and Richardson 1982). Synchronization of adult emergence may also be an advantage in these instances; species of both genera are autumnal for the most part and, perhaps as a consequence of lower temperatures at night, the adults are largely diurnal in activity. Daytime activity of caddisfly adults is found i n relatively few species of Trichoptera over all, and there seems a reasonable possibility that when i t does occur, synchronized emergence o f adults might help to compensate for the greater hazards o f diurnal reproductive activity. For some Neophylax that live i n streams of temporary flow, larval diapause serves to postpone oviposition until after summer drought (Wiggins 1973a). Diapause i n the adult stage is advantageous for species of the Limnephilidae and Phryganeidae inhabiting temporary pools (Novak and Sehnal 1963, 1965; Wiggins 1973a); sexual maturity of adults emerging in spring is delayed until late summer, when development is resumed, largely through the stimulus of shorter daily photoperiods. This postponement of oviposition places eggs in the pool basins in autumn when the moisture level of surface soil is being replenished, thereby avoiding the summer drought. Embryonic development proceeds and larvae break out of the egg chorions but can remain in the gelatinous egg-matrix for several months, even until spring, when flooded by surface water i n the pool basin (Wiggins 1973a). I n this way, diapause i n the adult brings about the initial delay in the life cycle, and larval development can coincide w i t h the occurrence o f temporary autumnal pools. However, the additional delay required for larvae to exploit temporary vernal pools appears to be facilitated by the more stable nature of the gelatinous egg-matrix and by the tendency of the larvae to remain w i t h i n the matrix until the stimulus of sutface water is received in spring. There is some evidence that small amounts of surface water can provide sufficient stimulus for larvae to leave the matrix and build cases i n the autumn. Final-instar larvae i n some species of the limnephilid genus Ironoquia aestivate i n unsealed cases around the edge o f temporary pools and streams during summer periods o f declining water levels, w i t h metamorphosis taking place in late summer (Flint 1958; W i l l iams and Williams 1975). Although photoperiod control has not been demonstrated, it seems likely that this situation differs from the preceding one only i n the imposition o f diapause on the last larval instar rather than the adult; the advantage in avoiding the summer drought period of temporary waters is the same. Diapause of eight to nine months was reported i n the eggs of Agapetus bifidus i n Oregon (Anderson and Bourne 1974). This may be the mechanism by which other species o f Agapetus are able to populate temporary streams, as reported i n Illinois by Ross (1944). 23

B i o l o g i c a l Considerations Life-cycle modification leading to accommodation of congeneric species i n the same habitat appears to be operating in Neophylax. Most species of this genus have autumnal emergence, but adults of the eastern N. ornatus emerge in spring. Life-history data compiled by Mackay (1969) reveal that larval feeding of this species occurs from summer through to December; larvae o f N. nacatus, an autumnal species i n the same habitat, feed during winter and spring. Coexistence o f species of Pycnopsyche i n the same general habitat is accommodated through differences i n their life history, behaviour, and feeding (Cummins 1964; Mackay 1972). Although the univoltine life cycles described above are the usual condition in T r i choptera, some species are known to be bivoltine or even trivoltine. Some species of Hydropsyche i n Ontario, for example, have a fast-growing summer generation of larvae maturing i n July or August and a slow-growing winter generation o f larvae maturing in A p r i l or M a y (Mackay 1979). Growth rates increased by high summer water temperatures and food quality raised the probability that a summer generation could mature before fall. Then there could be two overlapping generations per year as reported for Glossosoma penitum in Oregon (Anderson and Bourne 1974). Larval populations of Ceraclea transversa were found i n two cohorts in Kentucky (Resh 1976); one overwinters i n the last larval instar w i t h cases sealed in preparation for metamorphosis and emerges i n spring, and the other overwinters in the third or fourth instar and emerges i n summer. B y contrast, larvae o f some species in the Odontoceridae, Calamoceratidae, Beraeidae, and L i m n e p h i l idae evidently require more than one year to complete a cycle; this is a difficult point to interpret, for i n addition to collection o f specimens representing a broad span o f developmental stages at the same time, one also needs to have some information about the length of the adult emergence period. These are some examples o f deviations from the generalized life cycle. A l l of them have come to light in recent years, and it is likely that we have much to learn about how very diverse the life cycles of caddisflies really are. The final point to be discussed under life cycles concerns the term prepupa. This term has been widely used by workers on Trichoptera for the interval from the time when the pupal case is fastened to the substrate and the anterior and posterior openings are sealed off, to the time when larval-pupal ecdysis occurs, that is, the point at which the external form of the insect changes from larva to pupa. But used i n this sense, as Hinton (1971) has pointed out, the term prepupa covers several biological stages and events: (a) the larva sealed w i t h i n the pupal case in a resting condition for intervals from several days to several months i n genera such as Neophylax, Pycnopsyche, and Dicosmoecus; (b) larvalpupal apolysis in which the larval cuticle is separated from the pupal epidermis; and (c) the pupa when histological reorganization of metamorphosis is taking place within but not connected to the larval cuticle. These events are terminated by larval-pupal ecdysis, when the larval exuviae are cast off and the newly formed cuticle beneath gives the insect the typical pupal form. As knowledge o f the biology of Trichoptera increases, especially such aspects as the operation o f diapause, it becomes necessary to identify more precisely the stages at which certain events occur. Thus, i n the present work, the term prepupa is restricted to the period (a) above, when the larva is i n a resting condition, because i t establishes that the functional larva is closed off w i t h i n the pupal case, and that feeding has terminated. 24

B i o l o g i c a l Considerations Larval-pupal apolysis, (b) above, terminates the prepupal stage and marks a significant change because functionally the insect is no longer a larva but a pupa. Larval-pupal apolysis in Trichoptera can probably be detected well enough for practical purposes from certain external changes: in the majority o f families the middle and hind legs change from the normal active position i n which they are partially bent and directed anteriorly to a more or less distorted position i n which they become straightened and directed toward the posterior end of the insect; and i n all families the eyes and the muscles o f the legs and other parts no longer coincide w i t h their position i n the overlying larval cuticle. The term pharate pupa (Gr. pharos, a garment) is used to designate the period, (c) above, when the developing pupa is enclosed w i t h i n the detached larval cuticle (Hinton 1971). This phase of development is terminated by larval-pupal ecdysis. When a caddisfly leaves the pupal case to come to the surface for eclosion or emergence from the pupal cuticle, it is functionally an adult, and from the time o f pupal-adult apolysis i t is termed a pharate adult (Hinton 1971). The mandibles of caddisfly pupae are, in fact, moved by muscles of the adult, and the oar-shaped legs of the pupal cuticle are powered by the slender legs of the adult which lie beneath (Hinton 1949).

25

Morphology

Morphological terms o f a general nature can be found i n an entomological text or glossary. Those that have particular application to the Trichoptera are explained here and illustrated in Figures ni—vi. Morphological structures o f larvae i n many o f the same genera occurring in Russia were illustrated by Lepneva (1964, 1966). A distinction between spines and setae should be made at the outset. Spines are extensions or processes o f the cuticle; they may be short and pointed, longer and blade-like, comb-shaped, or o f some other form. Spines are one type o f surface sculpturing, and as an integral part o f the cuticle, they are retained on the exuvial sclerites after ecdysis; i t is likely that spines are largely protective i n function. Setae are innervated sense receptors; they arise i n alveoli or pits i n the cuticle and range widely i n size to include stout bristles, flattened scale-setae, and spurs. Setae are articulated cuticular appendages, and usually become separated from the exuviae at ecdysis, leaving the pit to mark their position, although some pits hold sensory receptors w h i c h lack setae. Varying distribution o f setae and pits provides important taxonomic information for larvae i n the sister order L e p i doptera; a comprehensive system o f chaetotaxy i n Trichoptera has been proposed ( W i l l iams and Wiggins 1981). HEAD

Sclerites o f the head capsule include a parietal on each side o f the head (Fig. H I E ) , and the two parietals are i n contact dorsally along a median coronal suture (Fig. I I I A ) ; between the parietals dorsally is the frontoclypeal apotome, separated from them by the frontoclypeal

I I I Morphology o f caddisfly larvae. A , head and thorax o f a limnephilid, dorsal, sal - setal area 1, etc.; B , labrum o f a limnephilid, dorsal, primary setae numbered; C, head o f a l i m nephilid, dorsal, primary setae numbered; D , head o f a limnephilid, ventral, primary setae numbered; E , head o f a limnephilid, lateral; F, gular area o f head o f a diplectronine hydropsychid, ventral 26

Morphology

27

Morphology sutures (Fig. ILIA). The coronal and frontoclypeal sutures together form the Y-shaped dorsal

ecdysial

lines along w h i c h the head sclerites separate at ecdysis (Fig. I I I A ) . Ventrally

the genal areas or genae o f the parietals are separated along the median line by the ventral

apotome (gular sclerite) w h i c h may separate the genae completely (Fig. lHD)or only partially, either as a single sclerite or as t w o - the anterior and posterior (Fig.

ventral

I I I F ) . A t ecdysis the parietals separate ventrally along the ventral ecydsial

apotomes

line (Fig.

I I I F ) . The exterior surface o f the head capsule is often roughened by spines, ridges, or various types o f sculpturing; on the interior, but often visible from the exterior, are round spots or muscle scars at attachment points for muscles o f the head. The labrum is hinged to the anterior edge o f the frontoclypeal apotome, and frequently bears a membranous anterolateral fringe (Fig. 12.2B, E). The eyes, strictly speaking, are clusters o f stemmata (Fig.

H I E ) , but the terms are used interchangeably here. Antennae i n most Integripalpia,

Glossosomatidae, and Hydroptilidae are rod-like and usually short (Fig. H I E ) , but much longer i n most Leptoceridae and some Hydroptilidae; i n the Annulipalpia, Rhyacophilidae, and Hydrobiosidae antennae are small and not clearly differentiated (e.g. Fig. 8.3B). Primary setae o f the head and labrum are usually stable i n position and are numbered (Fig. I I I B , C ) i n accordance w i t h the system proposed by Nielsen (1942); setae 8 and 18 arise on the ventral surface of the head (Fig. H I D ) . Secondary setae sometimes occur on the dorsum of the head as i n Figure 12.2E Mouthparts ( F i g . V I B ) are identified by standard terms. The silk produced by caddisfly larvae is emitted through a small orifice at the tip o f the labium; labial palpi are absent i n some families, submental

sclerites

differ widely i n shape and sometimes are fused. On the

maxilla adjacent to the labium is a rounded lobe (Fig. V I B ) , or a slender finger-like process (Fig.

4 . 2 B ) , bearing sensilla; differing views as to whether this structure is correctly inter-

preted as galea or lacinia have been summarized by Matsuda (1965), who concluded that in Trichoptera it is mainly a fusion product o f the two, which can be termed the maxillary lobe. Structures identified i n Figure V I B as cardo, stipes, palpifer, palpiger,

and mentum

are identified primarily by the sclerites borne on these parts. Mandibles have cutting edges of two basic types, evidently correlated w i t h feeding behaviour - a series o f separate points or teeth (Fig. 12.4D), or an entire, scraper-like edge (Fig.' 12.3D) - and are articulated w i t h the head capsule by means o f a knob-like ventral condyle and a dorsal cavity. The blades o f scraping mandibles which occur i n larvae that graze periphyton from rock surfaces are w o r n d o w n through constant abrasion against mineral substrates (Arens 1990, fig. 11);

consequently, these mandibles change i n shape through each instar (e.g. Wiggins

and Richardson 1982, figs. 3 1 , 32). THORAX

The pronotum is always covered by t w o heavily sclerotized plates closely appressed along I V Morphology o f caddisfly larvae, illustrated by generalized limnephilids. A , entire larva, lateral, abdominal segments numbered I - X ; B , abdominal segment I , dorsal; C , abdominal segment I , ventral; D , abdominal segment bearing branched gills, lateral; E , forked lamella enlarged i n face view and in profile, approx. x470; F, detail o f b i f i d filaments o f the lateral fringe 28

Morphology

antenna

29

Morphology the mid-dorsal

ecdysial

line (Fig. I I I A ) ; the prosternum

frequently bears sclerites. In sev-

eral of the case-making families (Integripalpia) there is a membranous, finger-like prosternai

horn (Fig. V I A )

trochantin

o f unknown function

(e.g. Bicchierai and Moretti

1987). The

(Fig. V I A ) , a derivative o f the prothoracic pleuron, is shaped characteristically

in different genera. The mesonotum

may be largely sclerotized, and the plate entire (Fig. 3.16A) or vari-

ously subdivided by median or transverse ecdysial lines; or the mesonotum may be membranous and w i t h or without small sclerites. I n most o f these conditions, mesonotal setae arise in three primary locations - setal area 1, sal, and sa3 (Fig. I I I A ) ; setae are variously modified in different genera and so numerous i n some larvae that the primary setal areas cannot be distinguished (Fig. 14.5B). Arrangement o f the sclerites and setae is o f taxonomic significance. Sclerotization o f the metanotum is variable; usually the sclerites are smaller than those on the mesonotum, but the setal areas have the same primary arrangement (Fig. I I I A ) . The pleuron o f both the meso- and metathorax comprises an anterior episternum

posterior epimeron separated by a darkened depressed line - the pleural The mesepisternum

and a

suture (Fig. V I A ) .

is extended anteriorly i n the Goeridae (Fig. 16.1B).

The thoracic legs i n some families are all approximately the same size, but i n most the fore legs are shorter and their segments stouter. Legs (Fig. V I A ) are variously armed w i t h spines, combs, and setae; spurs are very stout setae, usually at the distal end o f the tibia, and often paired. The basal seta o f the tarsal claw is enlarged to spur-like proportions i n some groups; the tibia and femur are secondarily subdivided into two parts i n some genera. The distinction between major and minor femoral setae is based on overall length and thickness. The trochanter is usually divided into t w o parts; the trochanteral brush is a tuft of setae often present on the distal part. ABDOMEN

Segment I in most families o f the Integripalpia bears a median dorsal side a lateral

hump and at each

hump (Fig. I V A ) ; the humps are retractile and in specimens

preserved

w i t h i n the case may be indistinct. On both dorsum and venter o f segment I (Fig. I V B , c) setal areas corresponding to sal, sal,

and sa3 o f the thoracic nota can be recognized.

This is essentially the arrangement on segment I i n such families as the Phryganeidae and Glossosomatidae,

and underlies setal patterns

in the Limnephilidae where the

diverse arrangements o f setae on segment I are o f considerable taxonomic value. I n some genera o f the Limnephilidae i t is not possible to distinguish between these setal areas (e.g. sal and sal i n F i g . 20.12D), a condition which for descriptive purposes I have usually inferred to be a result o f amalgamation. The boundary between dorsal and ventral sets is usually a single seta (Fig. IVA, c), sometimes two (Fig. 20.33A), on the ventral part o f the lateral hump, here designated the lateral

hump setae. The lateral humps

of segment I in several groups bear sclerites w h i c h are important taxonomically; since these sclerites are often lightly pigmented, they are best distinguished by a more

rigid

and shiny surface, and careful examination under good microscope illumination is necessary to distinguish them. Segment I X bears a dorsal sclerite 30

(Fig. I V A ) i n some families, and the arrangement o f

Morphology

V M o r p h o l o g y o f anal prolegs of caddisfly larvae. A, a philopotamid, lateral; B, a l i m nephilid, lateral; C, a glossosomatid, lateral; D , a goerid, dorsal, including segments Vlll and IX setae on segments vu, VIII, and IX can be of taxonomic significance. Occasionally when the sclerite is not pigmented, i t can be detected by the f i r m , shiny surface. The anal prolegs

exhibit significant structural diversity, and homologies designated

here for component parts are largely those proposed by Ross (1964). The condition i n Figure VA, from the Annulipalpia, is considered to represent the primitive type for the T r i choptera; in these retreat-making families and also i n the free-living Rhyacophilidae, the anal prolegs are elongate, separate, and very mobile. Bridging the flexible membranous connection between the lateral sclerite and the anal claw is a slender dorsal plate and ventral sole plate. I n the derivative condition seen in the Integripalpia (Fig. VB), it is inferred

that the prolegs have become short and thick, their bases swollen (Fig. VD); short, stout prolegs enable the larva to grip the interior of its close-fitting tubular case w i t h the anal claws, usually armed w i t h stout accessory hooks. I n most genera of the Integripalpia there is little evidence of a dorsal plate (Fig. VB), but a small sclerite incorporating the bases o f the stout, terminal setae termed the basal tuft does occur i n a few genera (Fig. VD), such as Goeracea

(Fig. 16.2G) and Goerita (Fig. 16.3D); i n Lepania

(Fig. 16.4G) a sclerite without

setae occurs ventrolaterad o f the basal tuft. Both types are interpreted here as dorsal plates. The Glossosomatidae o f the Spicipalpia (Fig. vc) are inferred to represent an intermediate condition i n w h i c h some shortening o f the proleg and reduction of the size of the anal claw 31

Morphology are evident relative to the condition o f these structures in the Rhyacophilidae. The anal prolegs are interpreted in larval Trichoptera as derivatives of segment X; ten abdominal segments are recognized in adult Trichoptera, and also i n larvae of the sister order Lepid optera. The lateral fringe

(Fig. IVA, D, F ) is a line or band of fine filaments along each side of

the abdomen in some families, principally of the Integripalpia; the filaments are bifid and usually hollow, but single filaments occur in Phylocentropus

(Annulipalpia) and in some

genera of the Hydroptilidae (Spicipalpia) ( K e r r and Wiggins 1995 ). In many Integripalpia there is a row o f tiny forked

lamellae (Fig. I V D , E ) on each side o f some abdominal

segments ( K e r r and Wiggins 1995 ) ; elsewhere these have been termed bifid processes and lateral tubercles. I n families of the Limnephiloidea, forked lamellae usually occur on most abdominal segments; in families of the Leptoceroidea and Sericostomatoidea, forked lamellae are almost always confined to segment V I I I . Serrate lamellae, which may be homologous w i t h forked lamellae, occur in larvae of Sericostomatidae, Helicopsychidae, and Beraeidae (Fig. 13.1 A ) . Respiratory exchange in Trichoptera occurs chiefly through tracheal gills which are f i l amentous extensions o f the body w a l l . Gills are usually located on abdominal segments, although they are found on thoracic segments, too, in some families; in larvae of a few species gills are lacking entirely. Tracheal gills are single (Fig. I V A ) , or branched basally (Fig. I V D ) , or they occur as terminal or lateral branches from a central stalk as in the Hydropsychidae (Fig. 7. l A ) . The gills are arranged i n definite positions i n three horizontal series - dorsal, lateral, and ventral - on each side of most abdominal segments, with an anterior and posterior g i l l position in each series; a segment with a complete complement w o u l d have six gills on each side. Thus, the precise position o f a g i l l on any given segment can be designated as anterodorsal, anterolateral, posteroventral, and so on. Arrangement of gills is significant taxonomically because some are often absent from particular positions, especially on the more posterior segments, but characters o f g i l l arrangement are frequently variable and are also subject to change from one instar to another. Diagnostic g i l l characters offered in this study are based on final instars. Beneath the cuticle o f each tracheal g i l l , fine tracheoles lie in the respiratory epithelium; Wichard (1973) showed in larvae o f the L i m n e p h i l i n i that an o p t i m u m system for respiratory exchange was achieved by the arrangement of these tracheoles parallel to the long axis of the g i l l , with uniform intervals between tracheoles. Osmotic regulation in at least some families of Trichoptera is mediated through rectal

papillae

as it is for insects generally (Schmitz and Wichard 1978); this appears to repre-

sent the primitive condition for Trichoptera, but in the Phryganeidae larvae swallow water to provide an additional source of the chloride ions absorbed by the rectal papillae (Schmitz and Wichard 1978). I n addition, however, ionic absorption for osmoregulation in several families o f Trichoptera is also achieved through anal papillae (Niiske and Wichard 1971). These are elongate lobes arising from w i t h i n the anal opening (Fig. 8.3A); anal papillae can be everted by pressure of the haemolymph and retracted by muscular action

V I Morphology o f caddisfly larvae. A , thorax and metathoracic leg of a limnephilid, lateral; B , maxillae and labium o f an apataniid, ventral 32

Morphology

33

Morphology (Wichard 1976). A n a l papillae occur in at least some genera of all families of the A n n u l i palpia and Spicipalpia. Niiske and Wichard (1972) found tracheoles in the anal papillae of glossosomatid larvae, but the tracheation is not as highly organized as in the respiratory epithelia of tracheal gills; they concluded that, in that family at least, the structures serve as ion transporting epithelia and have a reduced respiratory function. Anal papillae i n T r i choptera were often termed blood gills i n the older literature. Other structures involved i n ion absorption for osmoregulation are the chloride epithelia o f the Limnephilidae, Goeridae, Apataniidae, Uenoidae, Molannidae, and Hydroptilidae (Wichard 1976). I n larvae o f the Limnephilidae, usually on the venter of abdominal segments I I - V H , chloride epithelia are seen as ovoid areas o f modified cuticle bordered by a thin sclerotized line; these have been termed oval sclerotized rings in the taxonomic literature. I n some genera, especially o f the tribe L i m n e p h i l i n i , similar areas are present on the dorsum o f most o f these same segments (Fig. IVA, D ) , and there may also be smaller, circular rings o f the same structure on the sides of some segments dorsal to the lateral fringe (Wichard and Schmitz 1980). These rings enclose areas of the epidermis specialized for ionic transport (Wichard and K o m n i c k 1973). In l i v i n g larvae, chloride ions are absorbed from water passing through the case, accumulated i n the cuticle, and transmitted to the body through the chloride epithelium as osmoregulatory compensation for ions lost through renal excretion (Schmitz and Wichard 1975). The peripheral sclerotized ring is a differentiation of the epicuticle along the border between chloride epithelium and normal integument. The chloride epithelial areas are sometimes difficult to distinguish, but the thin sclerous ring can usually be detected by varying the direction and brightness of the microscope illumination.

34

Techniques

C O L L E C T I N G

To a considerable degree, the objective in collecting w i l l govern the method and the equipment used. The topic is first considered here from the viewpoint of discovering as far as possible the full diversity of caddisfly larvae in a given site. Other objectives are considered subsequently. Equipment for collecting caddisfly larvae need not be elaborate. For waters that can be waded, thigh-length rubber boots are useful; the main advantage is to have freedom to kneel down for a close look at the insects and what they are doing. A strainer of the finest mesh possible is useful for washing silt from samples o f gravel, sand, or leaves; plastic strainers compress easily for carrying and do not rust. After washing, larvae can be picked from substrate materials in clean water i n a small basin such as a white plastic photographic tray. A long-handled D-frame dipnet is essential, and should be provided w i t h a bag o f mesh size fine enough (e.g. 0.5 m m ) to retain smaller instars. Although useful i n many types of habitats, a dipnet of this type is especially valuable i n recovering very small larvae from rocks and gravel i n rapid currents. The method is the standard kick-sample technique, i n which the flat side of the net is held vertically as tightly as possible against the bottom substrate. Larger rocks immediately upstream o f the net are washed by hand and the current carries the dislodged insects into the net; bottom gravel is disturbed w i t h the feet to a depth of several centimetres, exposing burrowing larvae to the force of the current. A large white tray, of the order of 50 c m x 30 c m x 5 cm, filled w i t h clear water is required for sorting dipnet samples o f substrate materials. Finally, stainless-steel iris forceps are fine enough without being fragile, and fixed to a ring on a neck cord are almost loss-proof; a lOx loupe or hand lens fastened to the same neck cord enables one to see a surprising amount o f detail on specimens i n the field. Since there is no better indication o f the diversity o f larval Trichoptera than the microhabitats they occupy, a collector w i l l need to explore as many as possible. I n a stream, the under-surfaces o f large rocks i n the current are usually among the first sites investigated; but then samples o f the materials beneath the rocks should be taken, washed clean i n a 35

Techniques strainer, and inspected under water in a small tray. Moss growing on the tops of rocks often harbours larvae not found elsewhere. Since larvae of such genera as Neophylax and Psilotreta pupate i n clusters, it is often necessary to turn over many rocks to find any o f them. In shallow areas along the stream margin close visual inspection on hands and knees is informative, with substrate samples washed and sorted as described; sand and silt deposits washed i n this way often yield burrowing caddisfly larvae. Accumulations o f leaves and twigs are frequently productive, and samples should again be washed before sorting. Logs and branches should be inspected, and any cracks probed for pupae. For small springs, much the same pattern can be followed as for streams, but with particular attention to washing and searching samples of the water-saturated organic muck i n seepage areas at the head o f the spring. Growths of liverworts and mosses in dripping areas often harbour larvae. T h i n layers o f water running over rocks i n spring streams are sites for grazing larvae, as are spray zones above the water line. I n shallow waters along the shoreline of lakes, and in ponds and marshes where dense aquatic vegetation makes it difficult to see larvae, net samples of the plants can be washed and turned out i n a large basin of water for sorting. In deeper water similar samples taken from a boat i n surface mats o f plants such as Ceratophyllum often yield surprising numbers of larvae not otherwise seen. Deep bottom samples of soft materials can be taken w i t h an Ekman grab or similar device, and the materials washed i n a fine screen. Quantitative collecting is an important objective, but one difficult to achieve; the problematic subject of quantitative benthic collecting for aquatic insect larvae is discussed at length i n other references (e.g. Hynes 1970). Some relative quantitative base may be given to any of the collection methods outlined above by making as far as possible a uniform collecting effort over a given period o f time in similar habitats; or substrate samples o f a given area or volume can be taken and the animals removed and counted. Life-history analysis is a special aspect o f quantitative work, w i t h the objective o f determining the time and rate of larval development; samples taken at regular intervals over the full life cycle are required. Since the object is to establish what proportion of the total larval population is in each instar at these intervals, it is important to use a technique that samples early instars adequately. One complication here is that caddis larvae of several groups have been found i n bottom materials to depths o f 20-30 cm (Williams and Hynes 1974); and different instars may occur i n different micro-habitats. Measurement o f m a x i m u m head width has proved to be the best general index for determining the instar to which a caddis larva belongs. W i t h i n a single species, series of these measurements over the period o f larval development w i l l form into clusters separated by distinct gaps; the gaps indicate the rapid increase in size o f the soft cuticle at each larval ecdysis up to the head w i d t h o f the succeeding instar. Examples o f methods for analysing growth data o f this kind in relation to time w i l l be seen i n the ecological literature (e.g. Mackay 1969, 1972). I f the objective for collecting is to obtain specimens for rearing, the possibility of physical damage i n sampling must, o f course, be minimized. The respiratory requirements o f larvae can usually be accommodated during transit by a small amount o f water in jars o f appropriate size in a portable ice chest. When the air temperature is high, or when an ice chest is not available, larvae are better transported i n moist leaves than submerged i n water ( M i c k e l and M i l l i r o n 1939). 36

Techniques ASSOCIATING

LARVAL

STAGES

It need hardly be emphasized that knowledge about the biology of Trichoptera depends very much on k n o w i n g what the immature stages of the species do and when they do it; that knowledge is dependent to a large extent on a sound larval taxonomy. Since only about one-third of the 1400 or so species o f Trichoptera known i n Canada and the United States have been identified i n the larval stage, the importance o f gaining additional firm data on larval taxonomy is clear. O f the two general approaches to the problem o f establishing associations between larval and adult Trichoptera, laboratory rearing is the more precise. Usually habitat conditions can be simulated closely enough in the laboratory to sustain most larvae during development. Specifications for many types of rearing apparatus are available in the literature; a few examples can be found i n papers by Anderson (1974b), Bjarnov and Thorup (1970), Philipson (1953a), and Wiggins (1959). These attest to the fact that simple equipment is adequate for rearing; sophisticated laboratory streams are not necessary to generate this kind o f information, although they are o f course useful for behavioural study. Rearing can involve a series of larvae o f unknown identity collected together i n the same habitat; l i v i n g specimens should be examined under a low-power binocular microscope to ensure that all are the same in gross morphology and case structure, to the extent that one can discriminate. A technique by which larvae are anaesthetized w i t h carbon dioxide for close comparative examination has been described (Bray 1966). Part o f the series, say one-third, is then preserved and the remainder reared - at least five or six specimens i f possible, because the method is based ultimately on an assumption that the entire initial series represents a single species. That assumption can be avoided by starting w i t h a single egg mass, but the rearing process is much longer and feeding of early instars is often demanding. Eggs can be obtained from adults of k n o w n identity, and a procedure described by Resh (1972) provides considerable precision through stimulation of egg release from females of k n o w n identity. W i t h caddisfly larvae obtained by any o f these means, there is a tendency to cannibalism i n confined quarters, especially i n groups such as the Phryganeidae; separation of larger instars into individual containers is warranted as a routine procedure whenever the identity to be established is o f critical importance. A n exact record o f larval structure can be obtained by removing a pharate pupa from its case; placed in an individual container, the insect sheds the larval integument i n one piece and w i l l complete development without the case (Hiley 1969). Adults that emerge successfully should be allowed a day or two of activity to ensure that the teneral condition is past before they are preserved as study specimens; for this reason, provision should be made in the container for the adult to crawl up on some emergent object. Even i f adults die during emergence, the specimens should be retained because genitalic structures are well enough formed by that time for accurate identification to species. Pupal cases vacated by pharate adults should be carefully retrieved and a small plug of cotton inserted in the anterior opening to prevent the loss of larval exuviae; this pupal case, the cast pupal skin, and the adult should each be placed in separate shell vials labelled i n some way to designate unequivocally their connection, plugged with cotton, and placed i n a larger vial. A l l sets of these reared specimens should then be placed in ajar along w i t h the larval specimens preserved at the outset, and fully labelled to show that the 37

Techniques specimens were all collected at the same time and place and that the adults were reared. Specimens reared in this way provide valuable scientific data that are lost i f the results are not documented and preserved. The second general approach to the problem of establishing associations between larval and adult Trichoptera is a field technique known as the metamorphotype method. W h e n collections are made i n the same location at intervals over a year, i t is often possible to acquire series of specimens representing the development of particular species from larva to the pharate adult w i t h i n the pupal case. Shortly before emergence, the pharate adult has fully formed genitalic structures on which species identification can be based, especially i f it is a male; and the unopened pupal case also contains the larval exuviae compressed in a mass at the posterior end. W h e n carefully removed in a small dish of alcohol under a binocular microscope, the larval exuviae can be sorted out, and certain sclerites, particularly those o f head, thorax, and legs, can be compared with final-instar larvae collected earlier to establish the association. The method is not precise but, carefully followed within a single site, i t is reasonably accurate. Even when i t is possible to make only a single collection at a site, long series sometimes yield final-instar larvae and pharate adults; series o f this kind ought to be a primary objective i n any general collecting of Trichoptera. The Leptoceridae and Molannidae present a special problem here because the larval exuviae are ejected through the posterior opening o f the case shortly after ecdysis. A collector often finds larvae and pupae, but none developed to the pharate adult stage necessary for specific identification. Under this circumstance, some larvae should be preserved and a series of pupae maintained alive i n a small jar on damp moss or paper towel in a portable ice chest or a refrigerator. Development is usually completed and the adults emerge, making identification possible. W i t h a portable ice chest, this technique is especially useful for excursions o f several days or weeks by automobile; we have successfully transported many specimens i n this way, adults emerging continually. Occasionally one comes upon a site where emergence is long past and vacated pupal cases are the principal evidence. By collecting as many unopened pupal cases as can be found, and opening each one carefully in a small dish of alcohol under a binocular microscope, it is sometimes possible to find a pharate male adult that died after the genitalia were sufficiently sclerotized for identification. The larval exuviae in the same case then provide some evidence for larval identification. Specimens and exuviae supporting specific association between larval and adult stages and obtained by any of these methods should be carefully segregated i n separate shell vials in a larger vial or jar and provided w i t h a label fully documenting the circumstances of collection. It is costly i n effort and money to acquire data of this kind; workers should be encouraged to treat the specimens with the care given to type specimens, and to deposit them i n museum collections where they w i l l be available for future study. PRESERVING,

STORING,

AND SHIPPING

SPECIMENS

L a r v a e collected by freshwater biologists in ecological research or survey work all too often make inferior specimens for systematic study. Inadequate fixation of the tissues results in internal decomposition and soft specimens that soon break up; inferior specimens should not be acceptable. This is an unfortunate failing because accurate 38

Techniques identification often underlies the outcome o f these studies; and not infrequently specimens collected represent taxonomic information worthy o f retention in museum study collections. Deposition of voucher specimens i n museum collections for long-term reference purposes, now widely practised by ecologists, should be reason enough to ensure that the specimens are properly prepared. Ethyl or isopropyl alcohol diluted with water to 80% by volume is acceptable for longterm storage o f specimens; but its use as a fixative requires that the fluid be changed several times i n the first day or two of fixation because the amount of water introduced with caddisfly larvae and cases dilutes the small volumes normally used i n field collecting jars. A superior fixing agent used increasingly by workers on larval insects of all kinds is Kahle's fluid: Ethyl alcohol Formalin Glacial acetic acid Distilled water

15 parts by volume 6 1 30

This fluid penetrates the body rapidly enough to fix tissues before decomposition begins. Although most specimens are killed quickly, larger larvae can be killed faster in boiling water and transferred to the fixative. It is not necessary to change the fluid to compensate for dilution; the light abdomens of most caddisfly larvae do not darken as they usually do in alcohol, and some indication of the green and yellow colours is retained. Caddisfly larval specimens fixed i n this way have proved to be superior for study in almost every way. One disadvantage of the fluid is its penetrating odour under confined conditions, a problem minimized by transferring specimens fixed i n it for t w o or three weeks to 80% alcohol for long-term storage and study. Kahle's fluid is poured off (but not d o w n conventional drains), a water rinse added and poured off, and 80% alcohol added for storage. Transfer to alcohol removes the abdominal colours retained by Kahle's fluid, but otherwise the specimens are very good. Neoprene stoppers exposed to Kahle's fluid w i l l quickly deteriorate. Jars of 120 cc (4 oz) to 250 cc (8 oz) capacity are satisfactory as field containers; plastic tops are satisfactory i f not cracked, and metal tops can be lined with a polyethylene gasket. Kahle's fluid tends to seep out under polyethylene snap-caps. Other types of histological fixatives may be appropriate substitutes for preservation of insect larvae (see Stehr 1987). Storage of specimens by any o f the standard museum procedures is satisfactory, but they should be protected from the bleaching effect o f light. Small vials sealed w i t h corks or screw-caps are not safe against evaporation of alcohol over the long term; neoprene stoppers provide much better protection against evaporation but should be of sulphur-free neoprene to avoid discoloration of the alcohol and possible damage to specimens over long periods. Small jars o f 120 to 500 cc capacity, the lids lined with a polyethylene gasket, provide good protection against evaporation; individual lots o f specimens can be kept inside the jars i n shell vials plugged tightly w i t h cotton, w i t h each vial fully labelled. Since larval specimens are frequently sent from one worker to another, or materials are borrowed from a museum collection, it is important that the time and scientific data they represent are not jeopardized by inadequate attention to what might seem like trivial 39

Techniques details. Specimens preserved in fluid are relatively heavy and require a stout container and somewhat more substantial internal padding than dried insect specimens. Jars should not be allowed to come in contact w i t h each other in transit. A n y space between vials within a jar should be packed w i t h cotton to prevent their knocking together. Vials in ajar should be padded with cotton to f i l l any space beneath the lid. No air bubbles should be left in the same container as specimens because the insects are subjected to jostling and erosion of setae every time the bubble moves. A n important advantage of using shell vials plugged w i t h cotton within larger vials or jars is that air bubbles are easily avoided by inserting the cotton plug after the vial has been totally submerged in a larger vial or jar of alcohol. STUDYING

SPECIMENS

Stereo dissecting microscopes that provide adequate working space under the objective are appropriate for studying larval Trichoptera. L o w to moderate magnification up to lOOx is usually adequate. A strong light source is essential; varying the direction and intensity o f illumination is often helpful i n seeing obscure structures. Specimens are examined in a small dish of clear fluid, usually dilute alcohol for preserved material. The specimen must be totally submerged i n the alcohol; specimens projecting out of the liquid cause reflection of the light, distorting the image and making structures difficult to interpret. Small morphological structures, as on legs and anal prolegs, are often examined best when the appendage is removed and prepared as a temporary slide mount in glycerine; a compound microscope may be required.

40

SYSTEMATIC

SECTION

This page intentionally left blank

Key to Larvae of North American Families of Trichoptera*

1

Larva w i t h portable case o f sand grains resembling snail shell (Fig. 17.1c); anal claw w i t h comb o f teeth, not hook-shaped (Fig. 17. I D ) . Widespread 17 Helieopsychidae, p. 237 Larva w i t h case not resembling snail shell, or larva not constructing portable 2

case; anal claw w i t h apex forming stout hook (Fig. V A - D ) 2

( 1 ) Dorsum o f all three thoracic segments largely covered by sclerotized plates 3

(Figs. 3.10A, 7.5A)

Metanotum, and sometimes mesonotum, entirely membranous or largely so but 5

w i t h several pairs o f smaller sclerites (Figs. 8. I B , 20. 1B) 3

(2) Abdomen w i t h ventrolateral rows o f branched gills, and w i t h brush o f many long setae on anal proleg; posterior margin o f meso- and metanotal plates lobate (Fig. 7.5A); larvae construct fixed retreats o f detritus and rock fragments (Fig. 7.5G). Widespread

7 Hydropsychidae, p. 126

Abdomen lacking ventrolateral gills and brush o f setae on anal proleg (Fig. 3.11A); posterior margin o f meso- and metanotal plates straight (Fig. 3.10A, H ) 4 4

(3) A n a l prolegs projecting freely from abdomen, claw large and at least as long as its sclerotized basal segment (Fig. 6 . 1 A ) ; larvae construct fixed tubular retreats o f sand. Southwest

6 Ecnomidae, p. 123

A n a l prolegs usually not projecting freely from abdomen, claw always very small (Fig. 3.11A); minute forms usually less than 6 m m long, w i t h purse- or barrel-shaped portable cases (Figs. 3. I F , G ; 3.9F), or flat silken domes fastened to rocks (Fig. 3.16D, E ) . Widespread

3 Hydroptilidae, p. 71

*See qualifications under Use of Keys, p. 7. Figures m to v i are found in the Morphology section, all others under the family designated by the number preceding the period. 43

K e y to F a m i l i e s 5

(2) Antennae long and prominent, at least 6 times as long as wide (Fig. 19.1B); and/ or sclerotized plates on mesonotum lightly pigmented except for pair of dark curved lines on posterior half (Fig. 19.1B); larvae construct portable cases o f various materials. Widespread 19 Leptoceridae, p. 249 Antennae o f normal length, no more than 3 times as long as wide (Fig. HIE), or not apparent; mesonotum never w i t h pair o f dark curved lines as above 6

6

(5) Mesonotum usually lacking sclerotized plates (Fig. 8.1B), or with small sclerites covering not more than half o f notum (Figs. 23.6B, 23.10B); pronotum never w i t h anterolateral lobe (Fig. 23.6A, B ) 7 Mesonotum largely covered by sclerotized plates, variously subdivided and usually pigmented, although sometimes lightly (Figs. 20.1B, 24.2B); pronotum sometimes w i t h prominent anterolateral lobe (Fig. 13.1A, B) 15

7

(6) Abdominal segment I X w i t h sclerotized plate on dorsum (Fig. 20.15c) Abdominal segment I X w i t h dorsum entirely membranous (Fig. 8.1E)

8

8 11

(7) Metanotal sa3 usually consisting of cluster of setae arising from small rounded or ovoid sclerite; prosternai horn present (Figs. 23.9A, B ; 23.10A, B ) ; larvae construct tubular portable cases, usually of plant materials. Widespread 23 Phryganeidae, p. 374 Metanotal sa3 consisting of single seta without sclerite (Fig. 1.4B); prosternai horn absent (Fig. 1.4A); larvae either without case or with tortoise-like case of rock fragments 9

9

(8)

Basal half of anal proleg broadly joined with segment I X (Fig. 1.4E); anal claw with at least one dorsal accessory hook (Fig. 1 .4A); larvae construct tortoiselike portable cases o f rock fragments (Fig. 1.4F). Widespread 1 Glossosomatidae, p. 50 Most o f anal proleg free from segment I X (Fig. 4.2E); anal claw without dorsal accessory hooks, although secondary lateral claw may be present (Fig. 4.2A); larvae free-living without portable cases but construct fixed pupal enclosures. Widespread 10

10

(9) Tibia, tarsus, and claw o f fore leg articulated against ventral lobe o f femur to form chelate leg (Fig. 2.1c). Southwest 2 Hydrobiosidae, p. 67 Fore leg normal, not modified as above (Fig. 4.2D). Widespread 4 Rhyacophilidae, p. 110

11

(7) Labrum membranous and T-shaped (Fig. 8. I D ) , often withdrawn from view i n preserved specimens; larvae construct fixed sack-like nets of silk (Fig. 8.2F). Widespread 8 Philopotamidae, p. 150 Labrum sclerotized, rounded and articulated in normal way (Fig. 9.5B)

44

12

K e y to Families 12

(11) T i b i a and tarsus fused together on all legs ( F i g . 11.1 A, D ) ; mesopleuron extended anteriorly as lobate process (Fig. 11. I D ) ; larvae construct fixed tubular retreats. Southwestern

11 Xiphocentronidae, p. 185

Tibiae and tarsi separate, mesopleuron unmodified ( F i g . 9.4A) 13

13

(12) Trochantin o f prothoracic leg broad and hatchet-shaped, separated from epistern u m by dark suture line (Fig. 10.4c); larvae construct fixed tubular retreats on rocks and logs (Fig. 10. I E ) . Widespread

10 Psychomyiidae, p. 174

Trochantin o f prothoracic leg w i t h apex acute, fused completely w i t h epister14

n u m without separating suture (Fig. 9.3A) 14

(13) Tarsi o f a l l legs strongly flattened, tibiae shorter than tarsi (Fig. 5.1A); larvae burrow i n sandy deposits and construct tubes o f sand grains (Fig. 5. I D ) . Eastern and central

5 Dipseudopsidae, p. 118

Tarsi o f all legs normal and not flattened, tibiae longer than tarsi (Fig. 9.2A); larvae construct exposed funnel-shaped capture nets (Fig. 9.3D) or flattened retreats (Fig. 9.4E). Widespread 15

9 Polycentropodidae, p. 159

(6) A b d o m i n a l segment I lacking both dorsal and lateral humps (Fig. 14.2A), each metanotal sal lacking entirely (Fig. 14.2B), or represented only by single seta without sclerite (Fig. 14.4B); larvae construct portable cases o f various materials and arrangements. Widespread

14 Brachycentridae, p. 206

A b d o m i n a l segment I always w i t h lateral hump on each side although not always prominent, and usually w i t h median dorsal hump (Fig. 20.18A); metanotal sal always present, usually represented by sclerite bearing several setae (Fig. 20.1B) but w i t h at least single seta (Fig. 15.1B); larvae construct portable 16

cases o f various materials and arrangements 16

(15) Mesopleuron extended as an acute process ( F i g . 16.1A, B ) ; cases o f rock fragments. Widespread

16 Goeridae, p. 226

Mesopleuron not extended as an acute process ( F i g . 20.31A, B ) 17

17

(16) L a b r u m w i t h transverse row o f approximately 16 long setae across central part (Fig. 15. I D ) ; cases o f plant materials variously arranged. Eastern and western 15 Calamoceratidae, p. 218 L a b r u m not as above, usually w i t h only 6 long setae across central part (Fig. 18

20.22D) 18

(17) Antenna situated close to anterior margin o f eye ( F i g . 18. I D ) ; median dorsal hump o f segment I lacking (Fig. 18.1A); cases o f various materials and arrangements. Widespread

18 Lepidostomatidae, p. 241

Antenna not situated close to anterior margin o f eye as above, approximately as 45

K e y to F a m i l i e s close to anterior margin o f head capsule as to eye (Fig. HIE), or closer (Fig. 25.1B); median dorsal hump o f segment I almost always present (Fig. I V A ) 19

(18)

19

Antenna situated approximately midway between anterior margin o f head capsule and eye (Fig. I I I A , E ) ; prosternai horn usually present (Fig. V I A ) although sometimes short; chloride epithelia usually present on some abdominal segments (Fig. IVA, D ) 20 Antenna situated at or close to anterior margin o f head capsule (Fig. 25.1B); prosternai horn and chloride epithelia never present (Fig. 25.1 A ) 23

20

(19)

Mesonotal plates w i t h anteromedian emargination (Figs. 26.2B; 26.4B); portable cases very slender (Fig. 26.1c), or stouter and usually with small stones arranged linearly along each side (Fig. 26.2c). Widespread 26 Uenoidae, p. 413 Mesonotal plates lacking anteromedian emargination (Fig. 20.14B)

21

(20)

21

Mandibles usually w i t h uniform scraper blades (Figs. 12. I D , 12.3D); or i f mandibles toothed (Fig. 12.4D), metanotal sal w i t h 25 or more setae on membrane between sclerites (Fig. 12.4B); metanotal sal sclerites sometimes lacking (Fig. 12.5B); larvae construct cases mainly o f mineral materials. Widespread 12 Apataniidae, p. 190 Mandibles almost always toothed (Figs. 24.IE, 24.2H); metanotal sal lacking setae on membrane between sclerites, or fewer than 25 setae i f present (Figs. 20.20B, 20.21B) 22

22

(21)

Primary mesonotal plates subdivided once (Fig. 24.2B) or twice (Fig. 24.1B); larvae construct portable cases mainly o f mineral materials. Western, highly localized 24 Rossianidae, p. 399 Primary mesonotal plates not subdivided (Fig. 20.20B); portable cases of plant or mineral materials. Widespread, common 20 Limnephilidae, p. 268

23

(19)

Tarsal claw o f hind leg modified to form short setose stub (Fig. 21.1 A ) or slender filament (Fig. 21.2A); portable cases o f sand grains w i t h lateral flanges (Fig. 21.1c). Widespread 21 Molannidae, p. 352 Tarsal claws o f hind legs not different i n structure from those o f other legs (Fig. 22.4A) 24

24

(23)

Pronotum w i t h transverse carina extended as rounded anterolateral lobes (Fig. 13.1A, B); portable cases of sand grains (Fig. 13.1c). Eastern, highly localized 13 Beraeidae, p. 203 Pronotum lacking transverse carina, anterolateral corners not lobed, often pointed (Figs. 22. 1A; 22.6A)

46

25

K e y to F a m i l i e s 25

( 2 4 ) Dorsum o f anal proleg with cluster of approximately 3 0 or more setae posteromesad o f reduced lateral sclerite (Fig. 2 5 . I D ) ; fore trochantin relatively large, apex hook-shaped (Fig. 2 5 . 2 D ) ; portable cases mainly o f fine rock fragments (Fig. 25.1c). Widespread 25 Sericostomatidae, p. 4 0 4 Dorsum o f anal proleg w i t h no more than 3 - 5 setae posteromesad of lateral sclerite, sometimes with short spines (Fig. 22.5F), lateral sclerite not reduced as above; fore trochantin smaller, apex not hook-shaped (Fig. 2 2 . 1 A ) ; portable cases o f rock fragments. Widespread 22 Odontoceridae, p. 3 5 9

47

This page intentionally left blank

Suborder SPICIPALPIA: Closed-cocoon makers Larvae construct a closed, osmotically semipermeable, cocoon o f silk for pupation; since the water current cannot reach the pupa directly, respiration during metamorphosis is effected solely by diffusion o f oxygen across the wall o f the closed cocoon. A l l construction by larvae is for pupation, or derived from pupation behaviour with the time o f onset altered. Larvae differ in foraging and pupation behaviour within this group. I n the Rhyacophilidae and Hydrobiosidae, larvae are mainly predacious and free-living without portable cases. Larvae in the Glossosomatidae construct a precocious pupal shelter at the beginning of the first instar, and utilize i t as a portable case to provide protection while grazing on exposed rock surfaces. Larvae in the Hydroptilidae are free-living until the beginning of the final instar, when the pupal shelter is constructed to serve as an enclosure for the foraging larva. In the w o r l d fauna of Trichoptera, four families are assigned to the Spicipalpia (sensu Wiggins and Wichard 1989; Frania and Wiggins, in press). A l l four are represented in North America. 1 2 3 4

Glossosomatidae Hydrobiosidae Hydroptilidae Rhyacophilidae

49

1 Family Glossosomatidae

Glossosomatids live chiefly i n rivers and streams, where they are common and often abundant. A European species, Agapetus fuscipes Curtis, is reported from lakes (Mackereth 1956), and Glossosoma larvae have been collected along the rocky, wave-washed shore o f Lake Superior. The family is represented i n all faunal regions; six genera are recognized i n North America, where approximately 80 species are k n o w n i n the United States and Canada. Larvae o f this family are specialized for feeding on the uppermost exposed surfaces o f rocks, where they graze on diatoms, green algae, and fine organic particles (e.g. Anderson and Bourne 1974). Scraper mandibles lacking separate teeth, and a membranous fringe on the labrum, are typical adaptations for this method o f feeding. Morphologically the larvae are a homogeneous group. Only the pronotum is covered by heavily sclerotized plates, and prosternai sclerites are prominent; the nota o f the other two thoracic segments are largely membranous but small sclerites are present i n some genera. A l l three pairs o f legs are approximately the same size. A b d o m i n a l gills are always lacking, and anal papillae are present. The distal half o f the anal prolegs is free from the abdomen i n this family, a feature distinguishing it from case-making families o f the Integripalpia. A possible functional basis for this difference is that anal prolegs i n families making portable tube-cases are normally i n contact only w i t h the silken lining o f the case, where the claws anchor the end o f the abdomen; i n the Glossosomatidae, the claws o f the anal prolegs are extended through the opening o f the case to stabilize the larva on the external substrate. The architecture o f their portable cases makes the Glossosomatidae a distinctive group. Although frequently called saddle-cases, a more appropriate analogy for the ovoid, flatbottomed domes o f rock fragments is w i t h the shell o f a tortoise; a broad strap or plastron o f rock fragments across the venter leaves an opening at each end through which head and legs are extended. Certain features o f these cases are characteristic for particular genera, and are described under the generic headings. A l l cases have spaces between the rock pieces, permitting water to circulate around the larva and the pupal cocoon for respiration. There is a tendency i n several genera for larvae to spin a flexible silken membrane around the r i m o f the ventral openings; i n observing l i v i n g larvae one can see that these mem50

1 Family Glossosomatidae branes fold over the aperture when the larva withdraws into its case. I n some exotic genera, tubular extensions are added to these openings (e.g. Flint 1963, fig. 7). The hinged stone closure of cases in a series o f larvae collected i n Arizona and illustrated here (Fig. 1.6G) is a precise mechanism for closing the holes, confirming that there is selective advantage in a case-closure mechanism, perhaps to keep predacious insects from entering the case. Glossosomatid larvae reverse position within their cases easily; thus, w i t h no distinction between the front and rear o f the case, both openings are built alike. Larvae can feed while completely beneath the case, probably an important feature for the exposed upper surfaces of rocks where they graze. I t is likely that portable cases i n the Glossosomatidae represent primarily protective behaviour for exploiting food resources. Another unique feature of the glossosomatid case is that it is not as well suited to continual enlargement as are portable cases in the Integripalpia; usually each instar builds a larger case attached to one end of the existing case, finally cutting the old one away (Anderson and Bourne 1974). This behaviour results in cases being discarded several times during larval growth; but evidently these insects are geared to profligacy i n cases, for i n a Minnesota stream caseless larvae of Glossosoma intermedium drifted at rates up to 350 per hour per foot of stream width (Waters 1962). Under conditions of stress such as reduced current flow or high temperature, glossosomatid larvae abandon their cases, usually building new ones when conditions return to normal (Anderson and Bourne 1974). Prior to pupation, the larva cuts out the ventral strap, fastens the outer r i m o f the case to a rock, and spins an ovoid brown cocoon of silk. This closed cocoon is not attached to the inside of the enclosure of rock fragments, thus allowing free circulation of water on all sides (Wiggins and Wichard 1989, figs. 7, 10). The stout silk wall of the cocoon is inferred to be osmotically semipermeable since this property has been demonstrated for similar closed cocoons in the Rhyacophilidae (Wichard et al. 1993). From several lines o f evidence, then, construction and function of portable cases in the Glossosomatidae can be regarded as essentially different from that o f case-making families in the Integripalpia. The reason for these differences is that case-making by glossosomatid larvae is precocious pupation behaviour, and consequently is not homologous w i t h construction behaviour for larval foraging in the Annulipalpia or Integripalpia. Three subfamilies have been recognized, and all are represented i n North America. A G A P E T I N A E : Agapetus Head with ventromesal margins of genae not thickened, m i d ventral ecdysial line approximately 1V times longer than each divergent branch enclosing ventral apotome; submental sclerites separate; pronotum w i t h numerous setae around most of periphery: mesonotum with two small, lightly sclerotized areas, metanotum with two smaller sa3 sclerites; tarsal claws with basal seta nearly sessile; claw o f anal proleg w i t h one or t w o accessory hooks; anal opening lacking sclerotized bar along each side. The group is represented i n all faunal regions except the Neotropical, where evidently it is replaced ecologically by the Protoptilinae. This group has been designated as a tribe of the Glossosomatinae (Ross 1956), but the subfamilial level proposed by Martynov (1924) seems more i n keeping w i t h the distinctive larvae. 2

G L O S S O S O M A T I N A E : Anagapetus,

Glossosoma

Head with ventromesal margins o f 51

1 Family Glossosomatidae genae thickened, mid-ventral ecdysial line approximately same length as each divergent branch enclosing ventral apotome; submental sclerites fused; pronotal setae sparse; mesoand metanota lacking sclerites; tarsal claws w i t h basal seta on raised truncate base; claw o f anal proleg w i t h one or two accessory hooks; anal opening w i t h sclerotized bar along each side. The group is Holarctic and Oriental i n distribution. P R O T O P T I L I N A E : Culoptila,

Matrioptila,

Protoptila

Head w i t h ventromesal margins

of genae not thickened, mid-ventral ecdysial line approximately 17 times longer than 2

each divergent branch enclosing ventral apotome; submental sclerites separate; ventral apotome reduced to slender V-shaped sclerite; pronotal setae sparse; mesonotum bearing median sclerite w i t h smaller sclerite at each side; metanotum w i t h t w o small sclerites; tarsal claws w i t h basal seta frequently arising from side o f basal process, claws sometimes trifid; claw o f anal proleg w i t h four or more accessory hooks; anal opening usually lacking sclerotized bar along each side, but present i n some species. The group is represented in the N e w World and Asia; most genera occur in the Neotropical region (Flint 1963), where the Protoptilinae are the only glossosomatids present. K e y to G e n e r a * 1

Mesonotum without sclerites (Fig. 1.4B); head with ventromesal margins of genae thickened, median ventral ecdysial line approximately as long as each divergent branch enclosing ventral apotome (Fig. 1.4D); anal opening bordered on each side by dark, sclerotized line (Fig. 1.4E) (subfamily Glossosomatinae)

2

Mesonotum with two or three sclerites (Figs. 1.1 A , 1.6A); head with ventromesal margins o f genae not thickened, median ventral ecdysial line approximately l / l

2

times longer than each divergent branch (Figs. l . l B , 1.3B); anal opening 3

usually lacking dark, sclerotized line on each side (Fig. 1. IE) 2

(1) Pronotum i n lateral view excised about two-thirds anterolaterally to accommodate coxa (Fig. 1.2c); venter of abdominal segments VIII and IX each with pair 1.2 Anagapetus

of setae (Fig. 1.2F). Western montane regions

Pronotum i n lateral view about one-third excised anterolaterally to accommodate coxa (Fig. 1.4c); venter of abdominal segment v m lacking pair o f setae. 1.4 Glossosoma

Widespread 3

(1) Mesonotum w i t h three sclerites (Fig. 1.6A); head w i t h ventral apotome reduced to slender, V-shaped sclerite (Fig. 1.6B). Widespread (subfamily Protoptilinae) 4 Mesonotum w i t h two sclerites (Fig. 1.1 A ) ; head w i t h anterior ventral apotome not slender as above (Fig. l . l B ) . Widespread (subfamily Agapetinae)

*See qualifications under Use of Keys, p. 7. 52

1.1

Agapetus

1 Family Glossosomatidae 4

(3) Each tarsal claw terminating in three acute points, one representing the basal seta, but all approximately equal in length (Fig. 1 .5B). Southeastern 1.5 Matrioptila Each tarsal claw terminating in normal single acute point, but with smaller basal seta (Figs. 1.3c, 1.6c)

5

5

(4) Tarsal claws with basal seta long and slender, arising from side of stout process at base of claw (Fig. 1.6c). Widespread 1.6 Protoptila Tarsal claws with basal seta stout, larger than process at base of claw (Fig. 1.3c). Widespread 1.3 Culoptila

53

1.1

Genus A g a p e t u s

D I S T R I B U T I O N AND S P E C I E S Agapetus is represented in all faunal regions except the Neotropical. Approximately 30 species are known north o f Mexico, and although the group is widespread over much of North America, the diversity o f species is greater in southern and western areas. Larvae have been associated and characterized for A. minutus Sibley (1926), A. Mini Ross (1944), A. diacanthus Edwards (1956), and A. bifidus Denning (Anderson and Bourne 1974), but there is as yet no comprehensive taxonomy for identification of larvae to species. We have associated larvae for seven species. M O R P H O L O G Y In general, Agapetus larvae are similar to those o f the Protoptilinae. Study o f our larval glossosomatid collections indicates, however, that Agapetus larvae are the only ones i n North America w i t h two mesonotal sclerites (A); they are also distinctive in having more setae on the pronotum than larvae of other genera, especially near the posterior margin. Length o f larva up to 6 m m . C A S E Larval cases i n Agapetus (F, G) show some general similarity to those of Protoptila in having a relatively large stone on each side, and in being higher in relation to the length than cases of other glossosomatids. Edges of the main openings frequently have silken flaps that are manipulated by the legs of the larva to effect almost complete closure (Anderson and Bourne 1974). Length of larval case up to 7.5 m m . B I O L O G Y Larvae o f Agapetus live in streams of hilly terrain, generally in waters intermediate between the colder sites frequented by Anagapetus and Glossosoma and warmer sites where Protoptila occur. Larvae o f A. bifidus were, however, found in the same small Oregon stream w i t h Glossosoma and Anagapetus larvae, but were more abundant in slower sections than either of the others (Anderson and Bourne 1974); A. bifidus was also found to overwinter in the egg stage in diapause for 8-9 months, with rapid development of the larvae after hatching in March. The spring occurrence of A. Mini larvae in temporary streams in Illinois (Ross 1944) is probably dependent upon a similarly long egg-diapause. Food o f Agapetus larvae i n a Colorado stream was found to fluctuate seasonally between diatoms and detritus (Mecom 1972a). R E M A R K S Phylogeny, biogeography, and taxonomy o f Agapetus adults were summarized by Ross (1951b, 1956). The European species A. fuscipes is probably the best-known member of this genus; among several aspects, case-building was studied by Hansell (1968a), eggs by Anderson (1974b), and Nielsen (1942) found it to be one of the few T r i choptera w i t h seven larval instars.

Agapetus sp. (Virginia, Giles Co., 18 A p r i l 1968, R O M ) A, head and thorax, dorsal x58, B, head, ventral; C, mandible, ventral; D, tarsal claw o f middle leg, lateral; E, anal prolegs, caudal; F, case, ventrolateral x20; G, case, dorsal 54

Glossosomatidae: Agapetus 1.1

55

1.2 G e n u s A n a g a p e t u s D I S T R I B U T I O N AND S P E C I E S This genus is confined to North America where six species are known, but only in western montane areas. We have associated material for six species. M O R P H O L O G Y Larvae are similar to Glossosoma, sharing all characters listed for the Glossosomatinae. Anagapetus larvae can be distinguished by the more posterior origin o f the fore legs, resulting i n a deep lateral excision in the pronotum to accommodate the coxa (C); larvae of this genus are also distinguished from Glossosoma by a pair of primary setae on the venter of abdominal segment V I I I i n addition to the pair of setae on I X ( F ) . Length o f larva up to 6.5 m m . C A S E Larval cases are similar i n general shape and structure to those of Glossosoma, but frequently have some silk and sand grains around the ventral openings (G, H ) . Length o f larval case up to 7.5 m m . B I O L O G Y Anagapetus larvae are usually found i n the cooler headwater sections of mountain streams. Larvae of Anagapetus bernea Ross had one generation per year but, i n contrast to those o f Agapetus bifidus that occurred i n the same Oregon stream, fed during the winter months to reach the final instar by spring; diatoms, green algae, and detritus were ingested during summer months (Anderson and Bourne 1974). R E M A R K S Taxonomic data for Anagapetus adults were summarized by Ross (1951a); phylogeny and biogeography of the species have also been studied (Ross 1956).

Anagapetus bernea (British Columbia, E.C. M a n n i n g Prov. Park, 6 July 1969, R O M 690179) A, head and thorax, dorsal x57; B, head, ventral; C, prothorax, lateral, coxa outlined; D, tarsal claw of middle leg, lateral; E, anal prolegs, caudal; F, segments V I I I , I X , and anal prolegs, ventral; G, case, ventrolateral x l 7 ; H, case, dorsal 56

Glossosomatidae: Anagapetus 1.2

57

1.3 G e n u s C u l o p t i l a D I S T R I B U T I O N A N D S P E C I E S This genus is restricted to the New World, where most species occur in M e x i c o and Central America. Four species are, however, known in the southwestern states. T w o o f these, C. cantha (Ross) and C. thoracica (Ross), extend northward to W y o m i n g and are also recorded from the eastern part of the continent - C. cantha from Maine and Maryland, and C. thoracica from North Carolina (Flint 1974b). The larva for Culoptila was identified from an associated series o f C. moselyi Denning from Arizona provided by O.S. Flint (Wiggins 1977). We collected another series of larvae i n Utah w h i c h appear to be of the same genus. MORPHOLOGY Larval material available in Culoptila is typical for the Protoptilinae, and similar to Protoptila; the median mesonotal sclerite ( A ) is rounded posteriorly rather than angulate as i n Protoptila (Fig. 1.6A), but this may prove not to be consistent at the generic level when other larvae become known. The only reliable basis that we have found for distinguishing larvae of Culoptila from Protoptila is the much stouter basal seta o f the tarsal claw ( C ) , which is articulated at its own base and evidently homologous with the slender basal seta o f Protoptila (Fig. 1.6c). Examination for this character is best done w i t h a compound microscope on a temporary slide mount of a leg. Length of larva up to 3.5 m m . C A S E Larval cases in Culoptila ( D , E ) are not at all similar to those i n Protoptila, for instead of the large single side stones of the latter genus, the sides of the case are formed of many small rock fragments of fairly uniform size. Partial collars of silk are fastened around the periphery of each opening. Length of larval case at least up to 3 m m . B I O L O G Y Little is known about the biology of Culoptila. The Arizona larva illustrated was collected in Turkey Creek, Chiricahua Mountains; our Utah specimens were collected 29 July i n the Green River, a wide, rather warm and silt-laden river near Dinosaur National Monument. The type localities cited for C. cantha and C. thoracica (Ross 1938) suggest a river habitat as w e l l .

Culoptila moselyi (Arizona, Chiricahua Mts., 9 June 1968, U S N M ) A , head and thorax, dorsal x l 13; B , head and prothorax, ventral; C, tarsal claw of middle leg, lateral; D , case, ventrolateral x28; E, case, dorsal 58

Glossosomatidae: Culoptila 1.3

59

1.4 G e n u s G l o s s o s o m a D I S T R I B U T I O N A N D S P E C I E S Species of Glossosoma occur over much o f the Nearctic, Palaearctic, and Oriental faunal regions. Twenty-two species are known in North America, all but three of them confined to western montane areas. T w o of these three, G. nigrior Banks and lividum (Hagen), are common i n the northeastern part of the continent, the former extending westward to Minnesota; the remaining species, G. intermedium (Klapalek), is Holarctic and widespread i n North America through much of the eastern and central parts of the continent to Yukon and Alaska (Wiggins and Parker, i n press). Although larvae have long been identified to the generic level (Ross 1944, 1959), they are a homogeneous group, and no species taxonomy has yet been developed. The larva o f what is probably G. lividum (Ross 1956) was described by L l o y d (1921, as G. americanum), Sibley (1926), and Betten (1934). We have associated material for 14 species. M O R P H O L O G Y Larvae of Glossosoma share with those o f Anagapetus the several distinctive characters of the Glossosomatinae, but since the latter is confined to western montane areas, Glossosoma i n the rest of the continent can be recognized from the set o f subfamilial characters. I n the west where Anagapetus also occurs, the smaller lateral excision o f the pronotum is diagnostic for Glossosoma ( C ) , and Glossosoma larvae lack a pair of setae on the venter o f segment v m . Length of larva up to 9.5 m m . C A S E Larval cases o f Glossosoma ( F ) are similar to those of Anagapetus, but tend to be larger and usually lack membranes of silk around the ventral openings; rock fragments o f fairly uniform size are used i n both genera. Length of larval case up to 12 m m . B I O L O G Y Glossosoma are dominant tortoise-case makers o f cool, rapid streams (Ross 1951a). Glossosoma penitum, studied in an Oregon stream, was found to have two overlapping generations per year (Anderson and W o l d 1972; Anderson and Bourne 1974). I n a study o f the feeding habits of G. nigrior, Cummins (1973) found that larvae in a Pennsylvania stream fed largely on periphytic algae, but i n a M i c h i g a n stream detritus was the dominant food. Selection for particular species of diatoms by Glossosoma nigrior has been demonstrated (Oemke 1984). R E M A R K S Ross (1956) discussed phylogeny and biogeography o f Glossosoma, and summarized taxonomic data for adults. The three species recorded from eastern North America belong to the subgenus G. (Eomystra) (syn. Mystrophora) along w i t h one western species; most western species were assigned to the subgenus G. (Ripaeglossa), but one, G. penitum, to G. (Anseriglossa).

Glossosoma sp. (Ontario Durham Co., 6 Oct. 1951, R O M ) A , larva, lateral x 2 1 , tarsal claw of middle leg and anal proleg enlarged; B , head and thorax, dorsal; C, prothorax, lateral, coxa outlined; D , head, ventral; E, anal prolegs, caudal; F, case w i t h larva, ventrolateral x l 7 60

Glossosomatidae: Glossosoma 1.4

61

1.5 Genus M a t r i o p t i l a D I S T R I B U T I O N A N D S P E C I E S The genus Matrioptila consists of only a single species, M. jeanae (Ross), known from mountain terrain of southeastern North America: Virginia, Kentucky, Tennessee, North and South Carolina, Georgia, and Alabama. Larval and pupal stages were described by Flint (1962b); we collected larvae of this genus i n South Carolina and Georgia. M O R P H O L O G Y Larvae are typical members of the Protoptilinae in having three mesonotal sclerites and two small metanotal sclerites ( A ) . Matrioptila larvae are, however, distinctive because each tarsal claw terminates in three points o f approximately the same length ( B ) ; these points are asymmetrical, and evidently homologous w i t h the seta, process, and claw i n other protoptiline genera (Figs. 1.3c, 1.6c). Length of larva up to 3.5 mm. C A S E A l t h o u g h of typical glossosomatid architecture, cases of Matrioptila jeanae (C, D ) are flatter and more depressed than others i n the Nearctic fauna. Mineral particles of small and rather uniform size are used; in series of larvae we collected many cases were constructed at least partially of transparent particles, although this could be as much a consequence o f the materials available to the larvae as of their behaviour. Length of larval case up to 3 m m . B I O L O G Y Larvae were collected in cold, mountain streams. Final-instar larvae and pupae occur in M a y (Flint 1962b), adults in June. Gut contents of larvae (3) examined were largely fine organic particles. R E M A R K S Diagnostic characters o f adults o f M. jeanae were given by Ross (1938). The genus is regarded as one of the most primitive of the Protoptilinae (Ross 1956).

Matrioptila jeanae (South Carolina, Oconee Co., 18 M a y 1970, R O M 700354) A , head and thorax, dorsal x l l 4 ; B , tarsal claw of middle leg, lateral; C , case, ventrolateral x36; D , case, dorsal 62

Glossosomatidae: Matrioptila 1.5

63

1.6 G e n u s P r o t o p t i l a DISTRIBUTIONANDSPECIES Species o f Protoptila occur only in the New World, but are widely distributed in both the Neotropical and Nearctic faunal regions. Thirteen species are k n o w n north of Mexico and the group is represented i n most parts of the continent, north at least as far as central Manitoba and Alberta. The larva was identified for P maculata (Hagen) by Ross (1944); we have associated material for two species and have collected series o f Protoptila larvae from many parts o f North America. M O R P H O L O G Y Larvae are typical for the Protoptilinae, and similar to those of Culoptila, but evidently are reliably distinguished by the slender basal seta of the tarsal claws ( C ) . Larvae of some species have a sclerotized bar along each side of the anal opening as in the Glossosomatinae. Length of larva up to 3.5 m m . C A S E Larval cases i n Protoptila (E, F ) can usually be identified by the relatively large stone incorporated into each side; the cases are higher i n relation to width than those in most other genera although similar to Agapetus i n this respect. Length of typical larval cases up to 4 m m . In a series we collected i n Arizona, larvae and cases are similar to those of Protoptila, but each opening of the case is fitted with a stone hinged w i t h silk along the outer edge ( G ) ; l i v i n g larvae examined under a binocular microscope pushed aside the hinged stone when they extended their head and thorax, and the stone closed back into place when the larva withdrew w i t h i n its case. Because no other larvae that we have examined, including all others assigned to Protoptila, have a closure mechanism of this type, there is a possibility that these larvae belong to some other genus. Length o f larval cases i n this series up to 5 mm. B I O L O G Y Because Protoptila larvae live i n somewhat warmer streams, often larger and slower-flowing than other members of the family, they are the glossosomatids of drier and more evenly contoured central parts of the continent. Gut contents of larvae (3) examined were largely fine organic particles w i t h some diatoms.

Protoptila sp. (Ontario, Durham Co., 25 M a y 1953, R O M ) A , head and thorax, dorsal x83; B , head, ventral; C, tarsal claw of middle leg, lateral; D , anal claw w i t h four accessory hooks; E, case, ventrolateral x25; F, case, dorsal ? Protoptila sp. (Arizona, Yavapai Co., 4-5 July 1966, R O M ) ; G , ventral portion o f larval case showing hinged closure stones 64

Glossosomatidae: Protoptila 1.6

65

This page intentionally left blank

2 Family Hydrobiosidae

The Hydrobiosidae are widely distributed i n South America, Australia, and New Zealand; the family extends through the Pacific island network o f N e w Guinea and Indonesia to eastern Asia. In the New World, the genus Atopsyche is widespread i n Central America and reaches the southwestern United States. Larvae of this family are similar to the Rhyacophilidae i n structure and behaviour, and appear to f i l l the same free-living predator niche i n the southern hemisphere that Rhyacophilidae do in the northern hemisphere. Interestingly, neither family occurs i n southern Africa. The larvae are campodeiform, w i t h a prognathous head. As i n the Rhyacophilidae, only the pronotum is sclerotized, but the prosternum also bears sclerites i n some hydrobiosid genera. The second and third pairs of legs are similar i n structure, but the first legs i n Hydrobiosidae are modified, usually to form a chelate appendage. In Atopsyche, the single genus occurring in North America, the apical segments o f the fore leg close against a distal extension of the femur (Fig. 2.1c). Abdominal gills are lacking; the anal prolegs extend freely from the abdomen as in the Rhyacophilidae, but the claws are usually smaller than in that family. Larvae are free-living through all instars; at the end of the last larval instar, small pieces of rock are fastened together w i t h silk to make a dome-shaped pupal enclosure, which is fastened to a rock as in the Rhyacophilidae. Spaces between the rock fragments permit currents o f water to bathe the closed ovoid cocoon o f tough silk. The cocoon is inferred to be osmotically semipermeable, as are similar cocoons i n the Rhyacophilidae (Wichard et al. 1993).

67

2.1 Genus A t o p s y c h e D I S T R I B U T I O N A N D S P E C I E S Atopsyche is a large Neotropical genus w i t h many species in South America through Central America, Mexico, and the Antilles. Three of the species known in M e x i c o have been recorded from the southwestern United States: A. erigia Ross in Texas; A. sperryi Denning i n Arizona and New Mexico; and A. tripunctata Banks i n Arizona. We have Atopsyche larvae from Nevada. North American larvae o f Atopsyche are well known (e.g. Ross 1959), but only A. erigia has been described at the species level (Edwards and A r n o l d 1961). We have larvae for A. sperryi from Arizona. M O R P H O L O G Y Atopsyche larvae are similar to Rhyacophila but have distinctive chelate front legs ( A , C ) , i n which the shortened tibia, tarsus, and claw close against a concave extension of the femur. They are further distinguished by a broad prosternai sclerite ( D ) . Length o f larva up to 22 m m . ENCLOSURE

Pupal enclosures constructed just before pupation are usually dome-like

and of small stones fastened to a rock; spaces between the stones admit currents of water. W i t h i n the enclosure the pupa is sealed in the typical spicipalpian closed silk cocoon. B I O L O G Y Atopsyche larvae live in cool streams, where they are predacious; gut contents of larvae (3) we examined all contained arthropod remains. One can only agree with H i n t o n (1950), i n describing the unusual fore legs and their musculature, that the chelae are almost certainly used i n securing prey - but that has yet to be observed. REMARKS

Taxonomy of adults and phylogeny for Atopsyche

species were reviewed by

Ross and K i n g (1952).

Atopsyche

sp. (Arizona, Coconino Co., 9 A p r i l 1968, R O M )

A , larva, lateral x l 2 ; B , head, pro- and mesonotum, dorsal; C, fore leg, lateral; D , prothorax, ventral 68

Hydrobiosidae: Atopsyche 2.1

69

This page intentionally left blank

3 Family Hydroptilidae

Often called micro-caddisflies because they include the smallest Trichoptera o f 2 to 3 m m in length, the Hydroptilidae also include genera i n which the larvae reach 6 m m and differ little in size from some of the Glossosomatidae and Psychomyiidae. Hydroptilids occur i n all faunal regions, and although richly represented i n tropical latitudes where they account for a large part of the caddisfly fauna, they are still an abundant and highly diverse group through much o f North America. Sixteen Nearctic genera w i t h about 220 species are recognized north o f Mexico, and there can be little doubt that many more species are still to be discovered. I n the North American fauna there are hydroptilid genera characteristic o f all types o f permanent waters from cold springs through streams and rivers to lakes, but as in most parts of the w o r l d little study has been devoted to their biology. The classic w o r k by Nielsen (1948) on Danish species i n five genera is the source o f much that is known about the biology of the family. Information available on food i n various genera indicates that the larvae have capitalized on algae - consuming the cellular contents from filamentous forms and grazing on diatoms. Hydroptilids can be recognized by the sclerotized plates on all three thoracic nota, and by the general absence of gills on abdominal segments. But apart from these features shared i n common, they are highly diverse i n other ways, such as the overall shape o f the body, length of antennae, extent of ecdysial sutures of the head, presence o f mid-dorsal ecdysial sutures on the second and third thoracic nota, length o f legs, and structure of the anal prolegs. Larvae of several genera bear dorsal chloride epithelia on most abdominal segments which are areas specialized for ionic absorption i n osmoregulation (Wichard 1976). Diversity among hydroptilid genera is seen also i n case-making behaviour. The family is k n o w n generally as the purse-case makers, because for the most part final-instar larvae construct portable bivalve cases of silk, often w i t h sand grains, diatoms, or algal filaments incorporated. Most larvae enlarge their cases continually to accommodate the swelling abdomen; those w i t h bivalve cases cut open the ventral junction o f the t w o edges, add new material, and close the seam again with silk. Other larvae spin portable silken cases 71

3 Family Hydroptilidae shaped like flattened, bottomless bottles; in these cases new silk added to the posterior edges accommodates the growing larva. Still others, in the Leucotrichiini, spin a flattened retreat fast to a rock; since all cases in series o f this group that we have collected are o f approximately the same size, it appears that the larvae accommodate their ultimate space requirements at the beginning of construction. Finally, larvae of Mayatrichia and Neotrichia construct portable cylindrical cases similar in shape to those of most Integripalpia. According to Nielsen (1948), fifth-instar hydroptilid larvae leave a silken thread wherever they go. I interpret case-making behaviour by larvae in the Hydroptilidae as precocious pupation behaviour, as in the Glossosomatidae. Almost all of the cases constructed by hydropt i l i d larvae at the beginning of the fifth instar are essentially domes; the fixed retreats of Leucotrichia and Zumatrichica, and one of the portable case types i n Ochrotrichia are domes. The purse-cases constructed i n many genera are two domes joined at the base; the second dome represents behaviour homologous with the silken floor that hydroptilid larvae construct in their single-valve shelters (e.g. Fig. 3.10E). The flattened silk cases i n Ithytrichia and Oxyethira can be derived from typical purse-cases. Tubular cases in Mayatrichia show evidence of lateral seams, although cases i n Neotrichia known to me are cylindrical and without evidence of lateral seams. The life cycle of hydroptilid caddisflies is unusual because the first four instars are spent as free-living larvae without cases; these larvae have a coleopteran aspect (e.g. Fig. 3.6H). The onset of case-building behaviour in most genera is delayed until the beginning of the final instar. U p to the beginning of the fifth instar, larvae have a slender abdomen; but during the last instar the abdomen becomes enlarged w i t h the energy reserve stored by the final instar l i v i n g i n its case. Free-living, early instars occur in the same habitats in which they ultimately live in cases, and evidently utilize the same food resources as the older larvae (Nielsen 1948). I n temperate latitudes there is a tendency for larvae to overwinter as fifth instars w i t h cases and, in some genera at least (e.g. Agraylea, Hydroptila, and Oxyethira), to pass rather rapidly through the earlier instars. I n his study of Danish species, Nielsen (1948) found that larvae o f a species of Agraylea completed the first four instars in 11-21 days, and those o f Oxyethira in 13-16 days; he also found, however, that larvae of Orthotrichia and Ithytrichia required longer periods for early larval development as i n other groups o f Trichoptera. Hypermetamorphosis or larval heteromorphosis was first suggested for the Hydroptilidae by Needham (1902); but, as pointed out by Ross (1944), the suggestion arose through failure to recognize that t w o genera were represented in the material studied rather than the single one supposed. From Needham's illustrations, i t is clear that he had pupae and prepupae o f Ithytrichia, and larvae perhaps o f Oxyethira based on the row of setae on the dorsum o f abdominal segment I . Although this first inference o f heteromorphosis i n the Hydroptilidae was invalid, Nielsen (1948) reactivated the idea that ' i t is almost justifiable to speak of a hypermetamorphosis,' because the first four larval instars differ so greatly from the fifth i n structure and behaviour. Although larval heteromorphosis is generally considered an adaptation o f parasitic insects, current definition and examples (C.S.I.R.O., Insects of Australia, 1970; Snodgrass 1954) include several non-parasitic groups and would accommodate the Hydroptilidae as w e l l . Two subfamilies are recognized (Marshall 1979), both represented i n the Nearctic region. 72

3 Family Hydroptilidae PTILOCOLEPINAE

This is the most primitive group now extant in the Hydroptilidae, and in characters o f adults shows affinity w i t h the Glossosomatidae (Ross 1956; Marshall 1979). Only a few species are known, and larvae occur i n cold montane springs among liverworts and mosses. Larval heteromorphosis has been confirmed through collection o f early instars o f Palaeagapetus

by R.W. Wisseman in Oregon. The group is Holarctic; Ptilocolepus

in Europe, Palaeagapetus

occurs

in North America and Asia.

P T I L O C O L E P I N A E : Palaeagapetus

Larvae dorsoventrally depressed. Head w i t h dor-

sal ecdysial lines, anterior ventral apotome large and triangular, posterior ventral apotome small and triangular; postmental sclerites paired; labrum symmetrical, anterior edge emarginate mesally w i t h a row o f many short setae; mandibles short, each with mesal setal brush. Thoracic nota each w i t h median ecdysial lines, sternites lacking; legs short and approximately equal, preepisternite free on all thoracic segments. Portable larval case constructed o f two silken valves covered w i t h pieces of liverworts and mosses; case carried w i t h transverse axis horizontal. HYDROPTILINAE

This is a highly successful group o f Trichoptera, distributed around the w o r l d . Several tribes have been recognized, based for the most part on characters o f the adult stage (Marshall 1979). The Nearctic genera are classified as follows: HYDROPTILINI:

Agraylea,

Hydroptila,

Oxyethira,

Paucicalcaria

Larvae laterally

compressed. Head w i t h mouthparts usually specialized for feeding on cellular contents o f filamentous green algae. Thorax w i t h middle and hind legs tending to be longer and more slender than fore legs; tarsal claws moderately to very long, tarsi generally same length as claws; tiba and femur o f at least fore legs stout, tiba enlarged distoventrally. A b d o m i n a l segments w i t h chloride epithelia usually present on dorsum. Portable case o f t w o silken valves, often covered w i t h sand grains or algal filaments, carried w i t h transverse axis vertical. L E U C O T R I C H I I N I : Leucotrichia,

Zumatrichia

Larvae dorsoventrally depressed. Tho-

rax lacking median ecdysial line on mesonotum and metanotum; all legs similar, segments short and stout, tarsal claws short and stout, tarsus approximately twice as long as claw on all legs. Abdomen w i t h dorsal sclerite (chloride epithelium?) on segments I-Vin, wide but not ring-like; fifth instars usually w i t h segments V - V I I much enlarged. Larvae construct flattened retreats, resembling egg capsules o f leeches, consisting o f a dorsal, dome-like valve o f tough silk and a silken floor fastened firmly to the substrate; a circular opening at each end permits the larva to extend the slender anterior part o f the body to graze periphyton from the substrate around the case. Larvae inhabit running waters. The group occurs only i n the N e w W o r l d . N E O T R I C H I I N I : Mayatrichia,

Neotrichia

Larvae generally cylindrical, not strongly 73

3 Family Hydroptilidae depressed or compressed. Head elongate and tapered anteriorly, antennae long and prominent. Thorax w i t h legs long and slender, tarsi elongate and on hind legs at least 1 1 / times longer than claw. Abdomen w i t h segment I short, dorsal tergites only on segments V I I I and I X ; anal prolegs unusually long and slender. Lateral fringe o f single filaments sometimes present. Portable case cyclindrical and tapered posteriorly with subcircular openings; case constructed o f secretion alone, or w i t h mineral materials. This tribe is represented only i n the N e w World (Flint and Harris 1991); larvae inhabit running waters. 2

O C H R O T R I C H I I N I : Ochrotrichia, Metrichia Larvae laterally compressed, legs similar, tarsi short and stout, approximately same length as tarsal claws. Abdominal segments i n many species w i t h a dorsal sclerotized ring, presumably enclosing chloride epithelium. Portable case usually of typical hydroptiline structure, with two silk valves incorporating sand grains or filamentous algae, but occasionally of a single valve and carried tortoiselike as i n the Glossosomatidae. Larvae live i n running waters. O R T H O T R I C H I I N I : Ithytrichia, Orthotrichia The two genera assigned to this group by Nielsen (1948) and Marshall (1979) are each independently specialized i n structure and behaviour; larvae i n Orthotrichia are subcylindrical, but strongly compressed i n Ithytrichia. However, the larvae do share several characters (Marshall 1979), of which some are probably apomorphic: head w i t h anterior ventral apotome triangular and recessed mesally to accommodate the relatively narrow postmental sclerite (Marshall 1979, figs. 24, 28); labium broad and flat; mandibles tapered and flattened; prothoracic sternite a median point; first pair o f legs w i t h comblike spines (Fig. 3.11c); abdomen w i t h circle o f rings on segment I . S T A C T O B I I N I : Alisotrichia,

Stactobiella

Definition of this group is not yet resolved

(Marshall 1979; Harris and Holzenthal 1993). The key to genera which follows is based on fifth-instar larvae, w i t h cases. The key is not applicable to earlier free-living instars. vided a key to early instars o f European species i n Agraylea, Orthotrichia, and Oxyethira. Keys for identification of adults Hydroptilidae were provided by Blickle (1979).

for the most part those Nielsen (1948) has proHydroptila, Ithytrichia, o f all North American

K e y to G e n e r a * 1

Final-instar larva w i t h abdomen dorsoventrally depressed i n form (Figs. 3.2, 3.6,3.13,3.16)

2

Final-instar larva w i t h abdomen laterally compressed i n form (Figs. 3.4, 3.10), or uniformly rotund (Figs. 3.7, 3.11) 2

(1) Abdomen w i t h segments V and V I usually abruptly wider than I V in dorsal

*See qualifications under Use of Keys, p. 7. 74

5

3 Family Hydroptilidae aspect (Figs. 3.6, 3.16); fixed retreats on rocks, flat silken domes resembling egg capsules o f leeches (Fig. 3.6F).

(tribe Leucotrichiini) 3

Abdomen w i t h no segments abruptly wider than others (Figs. 3.2, 3.13) 3

4

(2) A b d o m i n a l segments w i t h dorsal sclerite bearing two small, circular lacunae (Fig. 3.16A); basal seta o f tarsal claw on all legs enlarged, claw appearing bifid (Fig. 3.16B). Montana

3.16 Z u m a t r i c h i a

A b d o m i n a l segments w i t h dorsal sclerite lacking circular lacunae (Fig. 3.6A); basal seta o f tarsal claw on all legs not greatly enlarged (Fig. 3.6B). Widespread in the United States 4

3.6 Leucotrichia

(2) A b d o m i n a l segments with fleshy tubercle on each side (Fig. 3.13A, E); portable case o f t w o flattened elliptical valves covered w i t h liverwort fragments (Fig. 3.13F). Eastern and western mountains

3.13

Palaeagapetus

A b d o m i n a l segments lacking fleshy lateral tubercles as above; meso- and metanotal plates lacking mid-dorsal ecdysial suture, but suture present on pronotum (Fig. 3.2A); larva free-living without portable case. Southwestern 3.2 Alisotrichia 5

(1) Tarsal claws stout and abruptly curved, each w i t h thick, blunt seta at base 6

(Figs. 3.3D, 3.15D) Tarsal claws slender, smoothly curved, each with thin, pointed seta at base (Fig. 3.4D-F), or basal seta lacking on middle and hind legs (Fig. 3.8A) 6

7

(5) Dorsal abdominal setae stout, each w i t h small sclerotized area around base, dorsal rings o f abdominal segments clearly delineated (Fig. 3.3A); larvae occur on red algae, portable case o f t w o symmetrical silken valves incorporating this alga (Fig. 3.3E, F ) . Eastern

3.3 Dibusa

A b d o m i n a l setae slender, their bases lacking sclerotized area, dorsal rings indistinct (Fig. 3.15A); portable case o f t w o symmetrical silken valves (Fig. 3.15E, F). Eastern and western 7

3.15 Stactobiella 8

(5) A l l tarsal claws w i t h basal seta (Fig. 3.4D-F) Tarsal claws o f middle and hind legs lacking basal seta (Fig. 3.8A). Southwestern

8

3.8 Metrichia

(7) Protibia w i t h prominent posteroventral lobe bearing short, very stout setae (Figs. 3.1c, 3.4D, 3.10c)

9

Protibia lacking prominent posteroventral lobe, pair o f normal setae usually present (Figs. 3.7c, 3.1 I D )

13

75

3 Family Hydroptilidae 9

10

(8) A l l three pairs o f legs approximately the same length (Figs. 3.4A, 3.10G)

10

M i d d l e and hind legs much longer than fore legs (Figs. 3.1A, 3.12A)

12

(9) Three filamentous gills arising from posterior end o f abdomen, one from dorsomedian position on segment I X , other two at lateral sclerites o f anal prolegs 11

(Fig. 3.4A)

Posterior end o f abdomen lacking 3 filamentous gills (Fig. 3.10G); portable case usually consisting o f two silken valves covered with sand grains (Fig. 3.10J, K ) , but sometimes o f single valve carried like tortoise shell (Fig. 3.10D, E). Widespread 11

3.10 Ochrotrichia

(10) Base o f tarsal claws smoothly contoured w i t h ventral margin of claw (Fig. 3.4E, F) ; portable case o f two silken valves usually covered with sand grains, sometimes w i t h diatoms (Fig. 3.4G, H). Widespread

3.4 Hydroptila

Base o f tarsal claws, especially o f middle and hind legs, quadrate and angular, not smoothly contoured w i t h ventral margin o f claw (Fig. 3.14A); portable case of two silken valves but w i t h little additional material added to exterior surface (Fig. 3.14c). Arkansas 12

3.14 Paucicalcaria

(9) Antennae long and slender, longer than diameter of cluster of stemmata (Fig. 3.12B); posteroventral lobe o f protibia prominent and linear (Fig. 3.12c); portable case entirely o f silk, shaped like flattened flask open at bottom (Fig. 3.12F, G ) . Widespread

3.12 Oxyethira

Antennae shorter, length less than diameter o f stemmata (Fig. 3.1A); posteroventral lobe o f protibia triangular (Fig. 3.1c); portable case o f two silken valves w i t h algal filaments incorporated concentrically (Fig. 3.1F, G ) . Widespread 13

3.1 Agraylea

(8) A n a l prolegs elongate and cylindrical, projecting prominently beyond general body outline (Fig. 3.7A)

(tribe Neotrichiini) 14

Anal prolegs short, conforming to general body outline, not projecting promi15

nently (Fig. 3.11A) 14

(13) Mesotibia w i t h pair o f short, stout setae located apically or nearly so (Fig. 3.7D); portable case o f silk sometimes incorporating soft mineral material, cylindrical but usually w i t h transverse or longitudinal ridges (Fig. 3.7F). Widespread

3.7 M a y a t r i c h i a

Mesotibia w i t h pair o f subapical setae located about one-third length o f tibia from distal apex (Fig. 3.9D); portable case o f fine sand grains, cylindrical (Fig. 3.9F). Widespread 15 76

3.9 Neotrichia

(13) Most abdominal segments w i t h prominent dorsal and ventral lobes (Fig. 3.5A);

3 Family Hydroptilidae portable case a flattened pouch of silk, posterior end open, anterior end reduced to small circular opening (Fig. 3.5E, F). Widespread

3.5 Ithytrichia

Abdominal segments lacking dorsal and ventral lobes (Fig. 3.11A); portable case o f silk, somewhat pod-like i n shape w i t h longitudinal ridges (Fig. 3.1 l G , H, I). Widespread

3.11 Orthotrichia

77

3.1 G e n u s A g r a y l e a D I S T R I B U T I O N A N D S P E C I E S Agraylea is a Holarctic genus w i t h four North American species. The Eurasian species A. multipunctata Curtis has long been thought to occur in North America, too (e.g. Ross 1944), but these records now seem more likely to be A. fraterna Banks; i n the far north A. cognatella McLachlan is a Beringian species occurring in Alaska, Yukon, and adjacent Asia (Wiggins and Parker, i n press). Morphological characters for all instars of A. multipunctata were described by Nielsen (1948); final instars o f North American Agraylea were characterized by Betten (1934) and Ross (1944). We have associated larvae o f A. saltesea Ross and several other series o f Agraylea larvae. M O R P H O L O G Y Larvae o f Agraylea ( A ) are strongly compressed and have lightcoloured sclerites. The antennae are short. The tibia of the fore leg is extended as a broad, triangular lobe ( C ) . The middle and hind legs are substantially longer than the fore legs ( A ) ; and there is a single sternal sclerite between the fore coxae ( B ) . A transverse sulcus, evidently a cuticular inflection serving as a muscle insertion, is well developed on the venter of abdominal segments I I - V I I inclusive ( A ) . The dorsal sclerotized rings surrounding the chloride epithelia are often small; there are no g i l l filaments on the apical abdominal segments as there are i n Hydroptila. Length of larva up to 6 m m . C A S E The larval case i n Agraylea (F, G ) is carried vertically and consists of two valves o f silk w i t h algal filaments incorporated concentrically. I n lateral aspect the ends of each valve are approximately the same width as the middle, and the valve is generally symmetrical bilaterally about its long axis; this evidence led Nielsen (1948) to conclude that A. multipunctata larvae make increments to their cases along both dorsal and ventral margins. Length o f larval case up to 6.5 m m . B I O L O G Y Agraylea larvae occur in lakes, ponds, and areas of reduced current in large rivers. According to Nielsen (1948), larvae o f A. multipunctata are found in beds of submerged aquatic plants where they feed on the cellular contents of filamentous algae; grasping of algal filaments is believed facilitated by the broadened fore femur and tibia. Siltala (1907b) found larvae of the same species in the G u l f of Finland to have ingested pieces of the marine alga Fucus, along w i t h diatoms and other algae. In other studies, food of Agraylea sp. in a Kentucky stream was found to include diatoms (Minckley 1963).

Agraylea sp. (Ontario, Leeds Co., 16 June 1966, R O M ) A , larva, lateral x23, chloride epithelium and antenna enlarged; B , prothorax, ventral; C, fore leg, lateral; D , middle leg, lateral; E , hind leg, lateral; F, case, lateral x l 2 ; G , case, dorsal 78

Hydroptilidae: Agraylea 3.1

79

3.2 Genus A l i s o t r i c h i a D I S T R I B U T I O N A N D S P E C I E S Alisotrichia is a New World genus largely confined to Central America and M e x i c o ; one species, A. arizonica (Blickle and Denning 1977), extends into the southwestern U.S. to Arizona and Utah. This species was originally described under Rioptila, now a j u n i o r synonym o f Alisotrichia (Harris and Holzenthal 1993) and assigned to the tribe Stactobiini. No larvae o f Alisotrichia have yet been found north o f the Mexican border. The larva o f another Mexican species o f Alisotrichia is illustrated here as the most likely representative of A. arizonica, although i t is not from the same species group. This material has been made available by S.C. Harris. M O R P H O L O G Y Final-instar larvae o f Alisotrichia are strongly depressed in form ( A ) . A l l legs are approximately the same length, and bear enlarged setae ( B ) . The thoracic nota also bear strongly enlarged setae, as do the abdominal segments. The anal prolegs and claws ( C ) are stout and largely concealed i n dorsal aspect by the dorsal sclerite o f segment I X . Length o f larva up to 2 m m . E N C L O S U R E Larvae of Alisotrichia do not construct a case or retreat at the beginning of the final instar as other hydroptilids do, but continue a free-living existence to the end of that stage (Flint 1970), when a simple, silken enclosure w i t h mesh-like openings is constructed ( D ) . Evidently there is no feeding activity w i t h i n this enclosure; shortly after its construction, larvae spin a typical closed pupal cocoon. B I O L O G Y Larvae k n o w n for Alisotrichia live in running waters. Deferral o f case-making until immediately before pupation indicates that the biology o f Alisotrichia larvae is different from most other hydroptilids. Perhaps the larvae are predacious and w o u l d be hindered by a case. R E M A R K S I n addition to Alisotrichia, the key may retrieve free-living fourth-instar larvae o f other hydroptilid genera such as Leucotrichia (q.v.). A m o n g North American Hydroptilidae, subterminal instars o f L. limpia Ross (Fig. 3.6H) are unusually large. Only a few species of Alisotrichia are known as larvae, and they reveal a rather wide range i n structure (Flint 1970). Consequently, distinction between Alisotrichia and subterminal instars o f Leucotrichia or other genera is at present uncertain. The larva illustrated and described as Alisotrichia sp. i n the first edition o f this w o r k (1977) was shown subsequently to be Leucotrichia limpia (Fig. 3.6H).

Alisotrichia sp. (Mexico, Nuevo Leon, municipio de Santiago, 12 M a y 1989, ROM) A , larva, dorsal x75 ; B , fore leg, lateral; C, segment I X and anal proleg, lateral; D , fixed pupal enclosure o f silken meshes, dorsal x40 , outline o f closed pupal cocoon beneath enclosure 80

Hydroptilidae: AHsotrichia 3.2

81

3.3 Genus D i b u s a D I S T R I B U T I O N A N D S P E C I E S This monotypic genus comprises only D. angataRoss, a species of local occurrence known through much of eastern North America from Georgia, Alabama, Arkansas, and Oklahoma north to Pennsylvania and Ontario. Larvae have been reared and the biology studied by Resh and Houp (1986). M O R P H O L O G Y This is the largest of the North American hydroptilids, and is distinguished by stout setae on the abdominal segments, each arising from a darkened, sclerotized base ( A ) . The dorsal chloride epithelia of the abdomen are relatively large and darkly pigmented. Although difficult to see unless mounted on a slide and examined under a compound microscope, the tarsal claws are distinctive from those of all other North American Hydroptilidae; stout and strongly curved ( D ) , they are suggestive of the claws of a sloth, and at the base o f each tarsal claw the spur is thick and blunt, somewhat as i n Stactobiella but smaller. Sclerotized parts are medium brown in colour, and the head is spotted w i t h rather large muscle scars. Length o f larva up to 6.7 m m . C A S E Final-instar larvae have typical hydroptiline cases of two symmetrical valves ( E , F ) , the outer layer o f each apparently consisting of elongate, more or less concentrically arranged pieces of the freshwater red alga Lemanea. Length of larval case up to 8 m m . B I O L O G Y The life history of this species and its association w i t h Lemanea australis were studied by Resh and Houp (1986). Although early instars ingest diatoms, final instars of D. angata feed entirely on tissues of Lemanea, and construct cases of the same material - a highly unusual example o f host specificity among Trichoptera, and even among herbivorous aquatic insects. For pupation, larvae fasten their cases to the alga. REMARKS

Relationships o f Dibusa remain unresolved (Marshall 1979). The first spec-

imens for study and illustration were provided by V.H. Resh and S.E. Neff.

Dibusa angata (Kentucky, Johnson Co., 16 Feb. 1973, ROM) A , larva, lateral x47, chloride epithelium enlarged; B , fore leg, lateral; C, middle leg, lateral; D , hind leg, lateral, tarsal claw enlarged; E, case, lateral x l 6 ; F, case, dorsal 82

Hydroptilidae: Dibusa 3.3

83

3.4 G e n u s H y d r o p t i l a D I S T R I B U T I O N A N D S P E C I E S Hydroptila is a large genus recorded from all faunal regions. In North America alone nearly 100 species are known, and the genus is represented throughout most of the continent. Larvae were associated for nine species by Ross (1944); colour of the sclerotized areas, the only basis found for separating the larvae to species, was variable and not sufficiently precise for diagnosis. We have associated larvae for 11 species. M O R P H O L O G Y The three apical abdominal gills ( A ) characteristic o f Hydroptila larvae are best seen against a dark background, and lost when larvae reach the prepupal stage. Larvae usually have three small prosternai sclerites ( B ) ; some larvae have a curved, transverse sulcus on the meso- and metanota ( C ) , but all lack the anterolateral lobes of the metanotum present i n most Ochrotrichia (q.v.). Some abdominal segments have dorsal chloride epithelia ( A ) . I n some species there is a pronounced hump on each side of abdominal segment IV. Length of larva up to 5 m m . C A S E Final-instar larvae have compressed cases of two silken valves covered usually w i t h a layer o f sand grains ( G , H ) , occasionally w i t h diatoms or filamentous algae. The case is carried vertically; the ventral edge is fairly straight, the dorsal edge more or less curved. According to Nielsen (1948) the larva enlarges its case by cutting open the ventral connection between the valves, adding materials along the ventral edge and at the ends; marked asymmetry in the case resulting from this behaviour is partly rectified toward the end of larval development when the larva adds new material only at the ends and no longer cuts open the ventral edge. Length of larval case up to 5.5 m m . B I O L O G Y Larvae of Hydroptila live in running waters and also in lakes. Nielsen (1948) found that all instars feed on filamentous algae by piercing the cells and eating the contents; but larvae of this genus i n Britain were reported to feed also on diatoms and unicellular algae (Percival and Whitehead 1929). Two North American riverine species were found to have a one-year life cycle (Anderson 1967b; Cloud and Stewart 1974), but a Danish species was reported to have two generations per year (Nielsen 1948); i n these studies most larvae overwintered as active fifth instars.

Hydroptila sp. (Ontario, Durham Co., 23 M a y 1958, ROM) A , larva, lateral x29, chloride epithelium, segment I X and anal prolegs enlarged; B , prothorax, ventral; C , meso- and metanota, lateral; D , fore leg, lateral; E, middle leg, lateral; F, hind leg, lateral; G , case, lateral x l 7 ; H , case, ventral 84

Hydroptilidae: Hydroptila 3.4

85

3.5 Genus I t h y t r i c h i a D I S T R I B U T I O N A N D S P E C I E S Ithytrichia is a small Holarctic and Oriental genus in which two North American species are known: /. clavata Morton, transcontinental and considered to be Holarctic (e.g. Fischer 1961, 1971); and /. mazon Ross in Illinois. I n North America, final-instar larvae of this genus were characterized by Ross (1944); several instars of the European species I . lamellar is Eaton were described by Nielsen (1948). We have larvae of /. clavata. M O R P H O L O G Y Final-instar larvae of Ithytrichia are strongly compressed laterally, and are distinctive because of the prominent lobate projection on the dorsum and venter o f most abdominal segments ( A ) . The tarsi are slender and elongate (B-D), approximately twice as long as the tarsal claws. A single median gill filament arises on segment IX, and the larva appears to be one of the few hydroptilids in which anal papillae are evident ( A ) . Length of larva up to 3.5 m m . C A S E The transparent larval case (E, F ) , made entirely of silken secretion, resembles a flat pouch open at the posterior end, but with the anterior opening reduced to a small hole through which the head and thorax of the larva can be extended. According to Nielsen (1948) the case of /. lamellaris is carried in such a way that the flat sides are dorsoventral, thereby imposing a 90-degree torsion on the thorax and the junction between abdominal segments I and I I ; an extended account of case-building in this species is given by the same author. The median silken filaments at the posterior end of the case illustrated are the beginning of the attachment for the closed pupal cocoon to a substrate; the anterior end of the pupa lies at the posterior end of the former larval case. Length of larval case up to 3.5 mm. B I O L O G Y Ithytrichia larvae live on rocks and on moss in running-water habitats, where their ability to hold the flat side of the case toward the substrate would be important. The food o f /. lamellaris is largely diatoms scraped from rocks and other substrates i n running water (Nielsen 1948); this species requires a full year to complete its life cycle in Denmark, overwintering as fifth-instar larvae with cases. I n a Texas river, fifth-instar /. clavata larvae were found to drift, mostly at night (Cloud and Stewart 1974).

Ithytrichia

prob. clavata (Ontario, Renfrew Co., 23 July 1969, R O M 690370)

A , larva, lateral x43, segments VIH and IX enlarged; B, fore leg, lateral; C, middle leg, lateral; D, hind leg, lateral; E, case, ventral x22; F, case, lateral 86

Hydroptilidae:

Ithytrichia

3.5

87

3.6 Genus L e u c o t r i c h i a D I S T R I B U T I O N A N D S P E C I E S Species of Leucotrichia occur only i n the New World, for the most part in Mexico and Central America. Three are known in North America: L limpia Ross in Arizona, Utah, and Texas, and L . sarita Ross in Texas, both ranging south through M e x i c o to Costa Rica; L. pictipes (Banks) is widespread over much o f the United States from Connecticut and Tennessee to Oregon and California. Diagnostic characters for larvae and adults of all three species were given by Flint (1970). We have associated larvae for L . limpia and pictipes. M O R P H O L O G Y Larvae are strongly depressed ( A ) . Final, retreat-dwelling instars in Leucotrichia share with Zumatrichia the extreme lateral distention o f abdominal segments V, VI, and VII ( A ) ; the abdomen is bright green in life. In Leucotrichia the basal seta of each tarsal claw is not enlarged ( B ) , and the dorsal abdominal sclerites lack lacunae ( A ) . Setal characters on the dorsum o f segment IX vary i n different species of Leucotrichia. A fourth instar larva o f L limpia Ross (H) exemplifies the distinctive morphology of subterminal instars o f hydroptilids. Length o f larva up to 5 m m . R E T R E A T Silken retreats of L . pictipes are flattened, elliptical, and fastened immovably to rocks (F, G ) ; they resemble the egg capsules of leeches. The larva encloses itself within the retreat at the beginning o f the final instar, leaving a circular rimmed opening at each end. I n a population studied in Montana by M c A u l i f f e (1982), over 75 per cent of the larvae occupied abandoned pupal retreats; the circular exit flap opened by the previous pharate adult was repaired w i t h silk by the new occupant. Length o f larval retreat up to 5.5 mm. B I O L O G Y I n L . pictipes studied in Montana by M c A u l i f f e (1982), larvae lived on the upper surfaces o f rocks i n running waters, grazing on surrounding periphyton and fine particulate detritus by extending the slender, anterior part of the body through the anterior or posterior openings o f the retreat. The grazing radius is determined by the larva's reach from its retreat, and results in an elliptical cropped area ( M c A u l i f f e 1984, fig. 1); the grazing territories surrounding the retreats lead to uniform spacing of larvae on rocks. Larvae completed the first four instars in less than two weeks. The capacity of the abdomen for food reserves is impressive; fifth-instar larvae we collected in August (Mississippi R., M i n n . ) before they began to build retreats had abdomens approximately equal in overall size to the head and thorax; i n older fifth instars w i t h retreats from the same collection, the combined length of the head and thorax was approximately one-quarter the length of the abdomen.

Leucotrichia prob. pictipes (Oregon, Umatilla Co., 18 Sept. 1966, ROM) A , larva, dorsal x34, w i t h dorsal sclerite enlarged; B , fore leg, lateral; C, middle leg, lateral; D, hind leg, lateral; E, segments v m , i x , and anal prolegs, lateral; F, retreat, dorsal x l 3 ; G, retreat attached to rock, lateral L . limpia (Utah, Washington Co., USNM) H, fourth instar of L . limpia, dorsal x30 88

Hydroptilidae: Leucotrichia 3.6

89

3.7 G e n u s M a y a t r i c h i a D I S T R I B U T I O N A N D S P E C I E S Mayatrichia is a small North American genus widely distributed from Mexico through much of the continent at least to southern Ontario; four species are known. Characters for larvae of M. ayama were given by Ross (1944); we have associated larvae o f M. ayama and M. ponta. M O R P H O L O G Y In the North American fauna, final-instar larvae o f Mayatrichia are similar only to Neotrichia. On the basis o f the material available for study, Mayatrichia larvae can be distinguished by a pair of short, stout setae on the mesotibia, located apically or nearly so (D). The legs ( C - E ) are relatively shorter, their segments thicker than in Neotricha, and there are short, stout setae arising over much o f each thoracic notum (B). In the specimens illustrated the head is more attenuate anteriorly than in Neotrichia, but this is not necessarily so for the genus as a whole. Larvae o f both Mayatrichia and Neotrichia have a lateral fringe o f single filaments ( A ) , unique among North American Hydroptilidae and Spicipalpia (Kerr and Wiggins 1995 ). A free-living, early instar o f M. ayama was illustrated by Ross (1944, f i g . 557). Length o f larva up to 2.5 m m . C A S E Cases of final-instar Mayatrichia larvae are cylindrical, slightly curved, tapered posteriorly, and made mainly or entirely of silken secretion, often incorporating soft mineral material such as travertine. The walls of the case are reinforced by ridges or ribs o f silk; cases of M. ponta have a pair of external ventrolateral ridges (F), and in M. ayama there is a series o f longitudinal and circular ridges (Ross 1944, fig. 558). Length of larval case up to 2.5 m m . B I O L O G Y Larvae occur on rocks in rapid sections o f rivers and streams, generally in running waters of rather large size. The attenuate head suggests some specialized feeding behaviour, although gut contents of larvae (3) examined were almost entirely fine organic particles. Emergence of adults was recorded in Illinois from June through early September.

Mayatrichia ponta (Oklahoma, M u r r a y Co., 7-8 M a y 1970, ROM 700320) A, larva, lateral x76, segments v i n , IX, and anal prolegs enlarged; B, head and thorax, dorsal; C, fore leg, lateral; D, middle leg, lateral; E, hind leg, lateral; F, case, ventrolateral x39 90

Hydroptilidae: M a y a t r i c h i a

3.7

91

3.8 Genus M e t r i e h i a D I S T R I B U T I O N A N D S P E C I E S The genus Metriehia occurs principally in central America and Mexico, w i t h species in South America and islands of the Caribbean (Flint 1972); two species are known to reach the southwestern United States in Arizona and Texas, and one is also recorded from Oklahoma (Ross 1944). We have an associated series of Metriehia

nigritta Ross from Arizona.

M O R P H O L O G Y Larvae of Metriehia are similar to Ochrotrichia, but the mesonotal and metanotal sclerites are shorter, and the setae along the anterior margin of the two nota are sparse, stout, and long ( B ) ; the tarsal claws on all legs are stouter, more strongly curved, and on the middle and hind legs lack a basal seta ( A ) . The tibiae of the fore legs bear a small posteroventral lobe ( A ) . Small dorsal chloride epithelia occur on abdominal segments il—VIII; lateral humps are apparent on segments II and IV i n some specimens ( A ) . Length o f larva up to 3.5 m m . C A S E Larvae construct a typical bivalve case of silk w i t h algal filaments added concentrically ( C ) . Length of larval case up to 4 m m . B I O L O G Y Larvae in this series were collected i n mats of filamentous algae in a small spring stream emerging from rock strata below a large spring-fed pond i n arid country. REMARKS

Metriehia

has been recognized both as a genus (e.g. Ross 1944; Blickle

1979) and as a subgenus of Ochrotrichia

(e.g. Flint 1972). Generic status seems to be

widely accepted, but has been compromised by lack of a congruent larval diagnosis (Flint 1972) - which is proposed here.

Metriehia

nigritta (Arizona, Yavapai Co., 3 Dec. 1986, R O M )

A , larva, lateral x33 , apical segments of legs enlarged; B , head and thorax, dorsal; C, case, lateral x20 92

Hydroptilidae: Metrichia 3.8

93

3.9 Genus N e o t r i c h i a D I S T R I B U T I O N A N D S P E C I E S The genus Neotrichia is represented only i n the Neotropical and Nearctic regions. Nearly 20 species are known north o f M e x i c o , and are recorded over much o f the continent from Oregon to Saskatchewan, Maine and south. Larvae were associated for several species o f Neotrichia characters for their separation were not found.

by Ross (1944), but reliable

M O R P H O L O G Y Neotrichia include the smallest North American caddisflies. Finalinstar larvae ( A ) are similar to those o f Mayatrichia, both genera distinctive in having long, slender tarsi on the middle and hind legs, w i t h the tibia o f the first legs lacking a ventral lobe ( C - E ) ; and they are further distinctive i n having the anal prolegs projecting free from the body ( A ) . Neotrichia larvae can be distinguished by a pair o f somewhat longer subapical setae on the mesotibia located about one-third the length o f the tibia from its apex ( D ) , and by the longer, sparser setae on the thoracic terga ( B ) . The legs in at least some Neotrichia larvae ( C - E ) are relatively longer and more slender than in Mayatrichia. As in Mayatrichia, a lateral fringe o f single filaments occurs on the lateral line ( A ) (Kerr and Wiggins 1995). Length o f larva up to 2 mm. We have collections of an aberrent larva from Arizona and Texas bearing lateral horns on the head ( G ) ; a pharate male from the Texas population ( M c K i t t r i c k Canyon, Guadalupe Mountains National Park; T . M . Green coll.) was identified by S.C. Harris as N. canixa Mosely, a species known otherwise from M e x i c o . C A S E It is likely that most o f the difficulty in distinguishing Neotrichia from Mayatrichia larvae can be resolved by the larval cases. Cases known for Neotrichia ( F ) are covered w i t h tiny sand grains, although in general shape they are cylindrical and slightly tapered as in Mayatrichia. Length o f larval case up to 2.5 m m . B I O L O G Y As in Mayatrichia, larvae occur on rocks in rapid sections o f rivers and streams. In Ontario we have taken larvae o f both Neotrichia and Mayatrichia at the same site.

Neotrichia sp. (Ontario, Hastings Co., 24 June 1973, ROM 730110) A , larva, lateral x62; B , head and thorax, dorsal; C, fore leg, lateral; D , middle leg, lateral; E, hind leg, lateral; F, case, ventrolateral x29 Neotrichia 94

canixa (Texas, Guadalupe Mountains Nat. Park, July 1988, ROM) G, head, dorsal

Hydroptilidae: Neotrichia 3.9

95

3.10 Genus O c h r o t r i c h i a D I S T R I B U T I O N A N D S P E C I E S Species of this genus occur only in the New World. I n North America north of Mexico approximately 50 species are known, largely in western and southeastern sections, w i t h fewer species i n the northeast. Larvae were identified for some species by Ross (1944), and characterized generally by Flint (1972). Larvae of three species have been described: O. susanae (Flint and Herrmann 1976); O. confusa (Morton) (Vaillant 1984); and O. arizonica Denning and Blickle (English and Hamilton 1986). We have larvae associated w i t h adults for 19 species, and other collections of larvae from many parts of North America. M O R P H O L O G Y Final-instar larvae of Ochrotrichia are generally similar to those of Hydroptila, but lack the apical filamentous gills of that genus. Generic diagnosis o f the larvae is complex because characters range widely. The meso- and metanota i n most Ochrotrichia larvae are produced as anterolateral lobes, the lobes extended beyond the point where the transverse sulcus terminates at the end of the anterior row of notai setae (H); however, in some larvae the anterolateral lobes are not as well developed. Prosternai sclerites are present, and there may be three as i n Hydroptila, or only two (B). There is little difference in size o f the three pairs of legs ( G ) . Abdominal segments frequently bear a dorsomedian sclerite ( A ) , presumably associated w i t h the chloride epithelium; in some larvae there is a raised prominence on each side of segment IV. A transverse sulcus on the venter of segments l i - V ( G ) i n some larvae is similar to Agraylea, but intersegmental grooves between abdominal sterna are not as prominent as i n Agraylea. Length of larva up to 5.5. m m . C A S E Most Ochrotrichia larvae construct laterally compressed cases of two silken valves covered w i t h sand grains (I, J, K), or occasionally filamentous algae. In a few species, e.g. O. confusa, O. quadrispina Denning and Blickle, and O. riesi Ross (Vaillant 1984), cases consist of a single, more convex dome carried tortoise-like; the ventral valve is represented by a flat sheet of silk ( D , E, F ) . Length of case up to 6 m m . B I O L O G Y Ochrotrichia larvae live in running waters of wide diversity from rivers to cold-spring runs and evidently i n temporary streams as well (Ross 1944). Our series w i t h single-valve cases were collected i n California and New York from populations where larvae were l i v i n g i n a thin f i l m of water flowing over rocks of a small spring stream; similar larvae found by Vaillant (1965, 1984) i n eastern and western North America fed by scraping diatoms from the rock surface. REMARKS

Taxonomy o f adults was reviewed by Denning and Blickle (1972).

Ochrotrichia

spp.

A - F (larva w i t h univalve case; California, E l Dorado Co., 18 July 1966, ROM) A , larva, dorsal x40, dorsal abdominal sclerite enlarged; B, prothorax, ventral; C, fore leg, lateral; D , case, dorsal x23; E, case w i t h larva, ventrolateral; F, case, diagrammatic cross-section, dorsal surface uppermost G - K (larva w i t h bivalve case; California, M a r i n Co., 7 June 1961, ROM) G, larva, lateral x47; H, meso- and metanota, lateral; I , case, diagrammatic cross-section near end; J, case w i t h larva, lateral x 2 1 ; K, case, ventral 96

Hydroptilidae: Ochrotrichia 3.10

97

3.11

Genus O r t h o t r i c h i a

D I S T R I B U T I O N A N D S P E C I E S Orthotrichia is a relatively small genus of wide distribution, w i t h species recorded from the Nearctic, Palaearctic, Oriental, and Ethiopian regions. Six species are now known in North America, largely in the eastern half of the continent; one species, O. cris ta ta M o r t o n , shows a westerly extension of this range to Montana and British Columbia. Diagnostic characters for final-instar larvae o f Orthotrichia were provided by Ross (1944, 1959), and morphological data for all stages of the European species O. tetensii (Kolbe) by Nielsen (1948). We have associated larvae for one species. M O R P H O L O G Y I n final-instar larvae of Orthotrichia, tarsi of the middle and hind legs are slender and elongate (D-F), only slightly longer than the tarsal claw, and the fore tibia (D) lacks the ventral enlargement and stout apical setae of such genera as Hydroptila; on each tarsus the distal spur is flattened (E). The fore coxa bears rows of spines ( C ) . The labrum is asymmetrical with a median sclerotized point (B). According to Nielsen (1948), larvae o f O. tetensii have three caudal gill filaments, much as in Hydroptila, but these become atrophied and disappear early in the fifth instar. Length of larva up to 3.5 m m . C A S E Cases of final-instar Orthotrichia larvae are distinguished from any others in the North American fauna. The case (G, H) is made o f silk alone, and although basically purselike i n design with slit-like openings at each end between two valves, i n cross-section ( I ) it is somewhat depressed. Characteristic of Orthotrichia cases alone are the dorsolateral, longitudinal ridges or keels on each side o f the mid-dorsal line. Length of larval case up to 3.5 m m . B I O L O G Y Larvae o f Orthotrichia live in submerged beds of aquatic plants along lake margins or in slowly f l o w i n g sections o f rivers. Nielsen (1948) observed that the pointed labrum enabled larvae of O. tetensii to puncture and feed on the contents of more robust algal filaments than could larvae in other genera.

Orthotrichia sp. (Ontario, Carleton Co., 28 June 1971, ROM 710492) A , larva, lateral x43, segment IX and anal proleg enlarged; B, labrum, dorsal; C, fore coxa, ventral; D, fore leg, lateral; E, middle leg, lateral, end o f tarsus enlarged; F, hind leg, lateral; G, case, dorsal x24; H, case, lateral; I , case, diagrammatic cross-section 98

Hydroptilidae:

Orthotrichia

3.11

99

3.12 Genus O x y e t h i r a D I S T R I B U T I O N A N D S P E C I E S Species of Oxyethira have been recorded from all major faunal regions o f the world. About 40 species are k n o w n i n North America, and they range widely over much of the continent from east to west. Larvae were associated with species in the genus by Ross (1944), and a pupal case illustrated; the larva, pupa, and biology o f O. leonensis Kelley were described by Back (1983). We have associated larvae for two species. M O R P H O L O G Y Larvae are distinguished primarily by the unusually long and legs o f the last two thoracic segments - each about 2 i / times longer than the fore very different from it in structure ( A ) . A l s o distinctive are the long antennae ( B ) linear distal lobe o f the fore tibia ( C ) . Clusters o f small, sharp spines are borne on sus ( C ) and at various points on the legs. Length of larva up to 4 m m . 2

slender leg and and the the tar-

C A S E I n North America, final-instar Oxyethira larvae can be recognized immediately by their flattened, flask-shaped cases made entirely o f silk with no other materials added (F, G). The head and thorax are extended through the thickened anterior neck o f the case, as illustrated; the truncate posterior end is not closed, although the free edges usually lie close together. It is to these free edges that the larva adds silk to accommodate its growing abdomen. A detailed account of case construction in the European O. costalis Curtis was given by Nielsen (1948); early fifth-instar larvae fashion a mass of detritus into a ring that serves as the form for spinning the anterior end of the case, and increments are added to the posterior end as required. Length of larval case up to 5 m m . B I O L O G Y Larvae of Oxyethira live i n lakes and other standing waters or in areas o f slow current in rivers. They frequent submerged beds o f aquatic plants where, according to Nielsen (1948), they feed on filamentous algae by puncturing the cells and eating the contents i n the same manner as larvae o f Ag ray lea and Hydroptila do; diatoms and entire algal filaments were also found i n larval guts (Siltala 1907b). Two generations per year were recorded i n Denmark for O. costalis (Nielsen 1948). Pupal cases of Oxyethira azteca Mosely were found fastened to a dragonfly nymph i n a stream in South Carolina (White and Fox 1979). R E M A R K S The systematic s and distribution of adults o f Oxyethira have been studied by Kelley (1984).

Oxyethira sp. (Wyoming, Teton Co., 14 Sept. 1966, ROM) A , larva, lateral x49; B , head, dorsal; C, fore leg, lateral, distal portion enlarged; D, middle leg, lateral; E , hind leg, lateral; F, case with larva, lateral x l 5 ; G , case, ventral 100

Hydroptilidae: Oxyethira 3.12

101

3.13 G e n u s P a l a e a g a p e t u s D I S T R I B U T I O N A N D S P E C I E S I n North America the genus Palaeagape tus is confined to mountainous areas where it is represented by two species: P. nearcticus Banks (syn. P. guppyi Schmid) occurs i n the west from California to Vancouver Island; P. celsus (Ross) is recorded from the Appalachian Mountains of North Carolina and Tennessee, and the Laurentians o f Q u é b e c . Colonies of both species are local in occurrence. Several species also occur in Japan (Ito 1991). The larva of P. celsus was described by Flint (1962a). M O R P H O L O G Y Larvae of P. celsus are depressed dorsoventrally, and are distinguished from all other North American hydroptilids by the truncate fleshy tubercles on each side of abdominal segments I-Vin ( A ) . A l l legs are similar i n structure (C, D). The maxillary palp and lobe are approximately the same length ( B ) . Length of larva up to 5 m m . C A S E The case o f Palaeagapetus larvae is carried with the flattened surfaces held dorsoventrally ( F ) ; but, as i n most other hydroptilids, the essential design is two silken valves w i t h slit-like openings at front and rear. Cases of Palaeagapetus are distinctive i n being covered with small pieces of liverwort. Length of case up to 6 m m . B I O L O G Y Larvae of Palaeagapetus occur i n small, cold seepage springs in growths o f liverwort on rocks and wood, often above the water surface. Further observations were provided by Flint (1962a). I n Japan, larvae fed on liverworts (Ito 1991); early instars consumed cell contents, and larger larvae the leaf tissue. R E M A R K S Palaeagapetus and the European genus Ptilocolepus constitute the Ptilocolepinae, considered the most primitive members of the Hydroptilidae. Larvae of P. nearcticus in a l l instars were provided for study here by N . H . Anderson and R. W. Wisseman.

Palaeagapetus celsus (Tennessee, Sevier Co., 10 M a y 1970, ROM) A , larva, dorsal x30; B , maxillae, labium and ventral apotome; C, fore leg, lateral; D , hind leg, lateral; E, segments v m , IX and anal proleg, lateral; F, case with larva, dorsal x l 2 ; G, case, lateral 102

Hydroptilidae: Palaeagapetus 3.13

103

3.14

Genus P a u c i c a l c a r i a

D I S T R I B U T I O N AND S P E C I E S species P. ozarkensis

This genus was erected to accommodate an aberrant

Mathis and Bowles (1989) from Arkansas.

Subsequently, the larva was associated w i t h the adult by M . L . Mathis, who provided larvae for study here. MORPHOLOGY

Larvae o f Paucicalcaria

are similar to Hydroptila,

as w o u l d be

expected because adults o f the t w o share a number o f characters. Based on material we have examined, the two can be disintguished by the structure o f the tarsal claws, particularly those of the last t w o pairs o f legs. Claws in Paucicalcaria

have a broad abrupt base,

with the basal seta arising from the angle between the base and the rest o f the claw (A). The claw is somewhat longer than the tarsus, approximately 1.2x; and the basal seta is also relatively long, approximately equal to one-half the length o f the claw. I n Hydroptila

(Fig.

3.4E), the base o f the tarsal claw is smoothly contoured w i t h the claw; the claw is approximately equal to the tarsus i n length, and the basal seta ranges between one-quarter to onehalf the length o f the claw - usually about one-third. Length o f larva up to 3 m m . CASE

Larvae o f Paucicalcaria

construct a typical hydroptilid bivalved case o f silk, but

evidently little additional material is added to the exterior surface of the silk (c);

fine

organic particles often adhere loosely to the silken exterior of the case. I n cases o f Hydroptila, the silken valves are covered and strengthened w i t h sand grains or algal strands. Length o f larval case at least up to 3 m m . BIOLOGY

Adults of P. ozarkensis

were collected at a small rapid, intermittent stream on

Magazine Mountain, Arkansas, the highest point between the Appalachian and Rocky Mountains. Larvae have been collected i n riffles o f Cove Creek, the same small Ozark stream where Paduniella

occur.

Paucicalcaria

(Arkansas, Washington Co., 16 A p r i l 1989, M . Mathis coll.)

ozarkensis

A, larva, lateral x43 , detail o f middle leg, dorsal abdominal sclerite, and anal proleg; B, head and thorax, dorsal; c, case, lateral x27 104

Hydroptilidae: Paucicalcaria 3.14

105

3.15 Genus S t a c t o b i e l l a D I S T R I B U T I O N A N D S P E C I E S Stactobiella is a small Holarctic genus with five North American species recorded over much of the continent west to British Columbia, north to Minnesota, Ontario, and Maine. Populations of all of the Stactobiella species are evidently local i n occurrence. Larvae were associated for S. palmata

(Ross) by Ross (1944), under the generic name

Tascobia.

M O R P H O L O G Y Final-instar larvae are generally similar to those of other genera in the Hydroptilinae, but especially to Dibusa because of the stout, sharply curved tarsal claws, each w i t h a thickened basal spur ( B - D ) . I n larvae examined, Stactobiella have smaller abdominal setae than do Dibusa, and the setae lack the sclerotized basal areas of that genus ( A ) . Although basal spurs of the tarsi in both genera are unusually stout and blunt, the spurs in Stactobiella are about half as long as the claw ( D ) , but relatively much smaller in Dibusa. Length of larva up to 3 m m . CASE

A l s o typical for the Hydroptilinae, the larval case of Stactobiella

consists of t w o

silken valves w i t h little or no additional materials, and w i t h a slit-like opening at each end (E, F ) . Although no detailed observations have been made on case-building, it is likely that the larva enlarges the case by slitting the seams, adding silk to the free edges, and binding them together again. The case is carried vertically. Length of larval case at least up to 3 mm. BIOLOGY

Larvae of Stactobiella

live on rocks in rapid, often small, streams. According

to Ross (1944), pupation and emergence of adults o f S. palmata

occur in early spring i n

Illinois, and therefore i t seems likely that this species overwinters as final-instar larvae i n cases. REMARKS

Diagnostic characters for males and females of two species of

were given by Ross (1944) under the name Tascobia,

Stactobiella

and for all males known at that time

by Ross (1948a).

Stactobiella sp. (Oregon, Benton Co., 10 A p r i l 1964, ROM) A , larva, lateral x63; B , fore leg, lateral; C, middle leg, lateral; D , hind leg, lateral, tarsal claw enlarged; E, case, lateral x 3 1 ; F, case, dorsal 106

Hydroptilidae: S t a c t o b i e l l a

3.15

107

3.16 Genus Z u m a t r i c h i a D I S T R I B U T I O N AND S P E C I E S The genus is represented only in the New World, and mainly in Central America and M e x i c o . Zumatrichia notosa (Ross), the only species known to occur north o f M e x i c o , has been collected in Montana (Flint 1970; Roemhild 1982). We have collections o f Zumatrichia MORPHOLOGY

larvae from Montana, Arizona, and Idaho.

Mature larvae are similar to Leucotrichia

i n the enormous lateral dis-

tention o f the middle abdominal segments (A); the median dorsal ecydsial line is lost from the mesonotum and metanotum, and the frontoclypeal ecdysial lines o f the head are also obscured. A n enlarged dorsal sclerite on segment I X bears many stout setae in Z. notosa (A, C), but this condition occurs also i n at least one species o f Leucotrichia.

Zumatrichia

I n larvae o f

the basal seta of the tarsal claw on all legs is greatly enlarged (B), giving the

appearance o f a bifid tarsal claw; the basal seta in Leucotrichia

is not enlarged. Length o f

larva up to 3 m m . R E T R E A T Larval retreats i n Zumatrichia

Leucotrichia,

species (D, E ) are generally similar to those in

and there appears to be no consistent basis for distinguishing between them.

The retreats are constructed entirely o f silk, and fixed in position on rocks. Length o f retreat up to 4 m m . B I O L O G Y Larvae o f Zumatrichia species live in fast-flowing parts o f running waters, evidently large rivers for the most part (Flint 1968a); adults o f Z. notosa were collected along the Missouri River i n Montana. Larvae graze on periphyton, reached by extending the head and thorax through the anterior or posterior openings i n the retreat. REMARKS

The larva of Z. notosa

is illustrated here from material provided by G.

Roemhild. Taxonomic data available for larvae and adults in the genus were summarized by Flint (1970).

Zumatrichia

notosa (Montana, Madison R., 18 June 1981, R O M )

A, larva, dorsal x53, dorsal abdominal sclerite enlarged; B, hind leg, lateral, tarsal claw enlarged; C, segments v m , I X , and anal proleg, lateral; D , retreat, dorsal x l 7 ; E, retreat on rock, lateral 108

Hydroptilidae:

Zumatrichia

3.16

109

4 Family Rhyacophilidae

The Rhyacophilidae are a large and important family in cool, running waters o f the H o l arctic and Oriental regions. T w o genera are recognized i n North America: and

Rhyacophila.

Himalopsyche

Rhyacophilid larvae are free-living, passing their entire larval existence without constructing either a portable case or a fixed retreat. Larvae crawl actively over rocks, and are reputed to leave a silken thread wherever they go (Ross 1956). Just before pupation, the larva fashions a crude enclosure o f small stones, either dome-shaped on a rock surface or ring-like between t w o rocks; w i t h i n this enclosure i t spins a closed cocoon o f tough silk and undergoes metamorphosis. Rhyacophilids are campodeiform caddis larvae w i t h head and mouthparts prognathous and a body o f strong muscular appearance w i t h deep constrictions between segments. O n the thorax only the pronotum is sclerotized, and all three pairs o f legs are similar i n size. Gills are present i n some species, but unlike the long filamentous gills o f other families, those o f the Rhyacophilidae are stiff and often occur in dense tufts. A sclerite is always present on the dorsum o f segment I X . A n a l prolegs are strongly developed, projecting freely from the body for their entire length, and presumably help to maintain stability o f the larva on rocks i n currents. A l t h o u g h generally regarded as one o f the most primitive families o f the Trichoptera, the Rhyacophilidae have been extraordinarily successful in generating species; but ecologically they have progressed scarcely at all beyond cool, lotie waters. Taxonomy and phylogeny o f adults o f all genera were reviewed by Ross (1956). K e y to G e n e r a * 1

Dense tuft o f stout gills on side o f meso- and metathorax and on abdominal segments I - V I I I (Fig. 4.1A); final-instar larva up to 32 m m long. Western 4.1 Himalopsyche

*See qualifications under Use of Keys, p. 7. 110

4 Family Rhyacophilidae Tufts o f gills usually absent (Fig. 4.2A), but i f present, tufts neither as dense nor on as many segments as above; final-instar larvae not more than 25 m m long. Widespread

4.2 Rhyacophila

111

4.1 Genus H i m a l o p s y c h e D I S T R I B U T I O N A N D S P E C I E S This is largely a genus o f the Oriental and Asian Palaearctic regions w i t h one species, H. phryganea (Ross), recorded from western North America; this single species is known from California, Oregon, and Washington in both the Cascade and Coast ranges. The larva o f H. phryganea series o f them.

was described by Flint (1961b); we have collected several

M O R P H O L O G Y Himalopsyche larvae are large and stout-bodied ( A ) . Although O l d World larvae of the genus frequently have lateral processes bearing short gill filaments on each abdominal segment (Lepneva 1964, fig. 310; Schmid and B o t o s à n e a n u 1966, p l . V I , fig. 1), there are no lateral processes in H. phryganea. A dense tuft o f stiff gill filaments arises from the sides o f abdominal segments i - v m and from the meso- and metathorax; these tufts are evidently denser and present on more segments than i n any North American Rhyacophila. A n ovoid sclerite is present on the venter o f most abdominal segments ( A ) . Length o f larva up to 32 m m . E N C L O S U R E Pupal enclosures o f H. phryganea are elongate domes constructed o f rather uniform small stones fastened together, leaving spaces for water to enter and circulate around the cocoon. Length o f enclosure at least to 25 m m . B I O L O G Y Larvae o f Himalopsyche are recorded from mountain streams o f many kinds including torrents; collections o f H. phryganea have been made at elevations between 2000 and 5000 ft (600 and 1500 m) (Schmid and B o t o s à n e a n u 1966). Our collections o f larvae o f this species were made for the most part i n rather small mountain streams. Guts of larvae (3) that we examined all contained arthropod parts. R E M A R K S Taxonomy o f adults and phylogeny of Himalopsyche reviewed by Ross (1956) and by Schmid and B o t o § a n e a n u (1966).

Himalopsyche

phryganea

species have been

(Oregon, Benton Co., 3 June 1968, ROM)

A , larva, lateral x6, detail of anal claw and ventral sclerite; B , dorsal sclerite o f segment I X , dorsal 112

Rhyacophilidae: Himalopsyche 4.1

113

4.2 Genus R h y a c o p h i l a D I S T R I B U T I O N AND S P E C I E S Rhyacophila is the largest genus in the Trichoptera, with close to 500 species widely distributed through the Holarctic and Oriental regions. More than 100 species are k n o w n in North America, and they occur in most parts of the continent where surface relief is sufficient to sustain lotie habitats. Larvae for North American species have been described by several workers, including Vorhies (1909), L l o y d (1921), Ross (1944), Flint (1962c), and Smith (1968b; 1984a, b). We have abundant collections and associated series for many species. M O R P H O L O G Y Taxonomy o f Rhyacophila larvae is not yet sufficiently explored for diagnostic limits to be fixed for this genus. I n some species the lateral sclerite o f the anal proleg is developed into a curved spike, as in the eastern R. fuscula (Walker) (A, c ) ; but i n most species the anal proleg is unmodified ( E ) . Abdominal segments usually lack filamentous gills, as i n the larva illustrated, but gills of several types are present i n some species; gills as stout and densely clustered as in Himalopsyche are very unusual i f they occur at all, in North American Rhyacophila. Larvae differ considerably in conformation of the head, in colour markings, and in details o f the mandibles and anal prolegs. Ventral abdominal sclerites similar to those in Himalopsyche are present i n at least some species of Rhyacophila. Length o f larva up to 23 m m . E N C L O S U R E Larvae build only a crude pupal enclosure of small stones, perforated with spaces enabling a current of water to bathe the closed cocoon. B I O L O G Y Rhyacophila larvae live in a wide range of running-water habitats, but some species are evidently adapted to temporary streams (Ross 1944). Several species frequently occur together i n the same stream; temporal and spatial separation in such instances was documented by Mackay (1969) and Thut (1969). In general, Rhyacophila larvae are free-living predators, and some species exhibit a preference for certain groups of prey organisms ( M a l i c k y 1973). The biology and life cycle of five species of Rhyacophila were studied by Manuel and Folsom (1982). Larvae of a few species are herbivorous, feeding on vascular plant tissue both living and dead, and on algae (Smith 1968b; Thut 1969). R E M A R K S Taxonomy o f adults and phylogeny have been reviewed by Ross (1956) and Schmid (1970).

Rhyacophila fuscula (Ontario, A l g o n q u i n Pro v. Park, 20 M a y 1959, ROM) A , larva, dorsal x7, detail o f anal proleg; B , maxillae and labium, ventral; c, anal proleg, lateral; D, fore leg, lateral R. banksi Ross ( Q u é b e c , Rouville Co., ROM); E, anal prolegs, dorsal 114

Rhyacophilidae: Rhyacophila

4.2

115

This page intentionally left blank

Suborder ANNULIPALPIA: Fixed-retreat makers Larvae are campodeiform with a prognathous head; the anal prolegs are elongate and the claws are prominent. They forage mainly from a stationary position, collecting food transported by water through filtering or grazing on deposits of fine organic particles; they also graze on diatoms. Larvae construct a fixed tubular retreat at the beginning of the first instar, supplemented in some families by a capture net of silken threads. For pupation, most larvae construct a protective dome o f rock fragments at the end of the last larval instar; the inner cocoon is osmotically permeable, and in most families, water currents enter the cocoon through small openings at each end, bathing the pupa directly during metamorphosis. Eight families make up the w o r l d fauna of the Annulipalpia (sensu Wiggins and Wichard 1989; Frania and Wiggins, in press ). Seven of them are represented in North America, and only the Stenopsychidae (see Lepneva 1964; Wiggins 1982) do not occur on this continent; the Stenopsychidae and Philopotamidae constitute the superfamily Philopotamoidea. Evidence supporting recognition of the superfamilies Philopotamoidea (p. 9) and Hydropsychoidea (p. 9) was reviewed by Frania and Wiggins (inpress). 5 6 7 8

Dipseudopsidae Ecnomidae Hydropsychidae Philopotamidae

9 Polycentropodidae 10 Psychomyiidae 11 Xiphocentronidae

117

5 Family Dipseudopsidae

Larvae of this family are among the most unusual i n the Trichoptera. The fixed silken tube covered w i t h sand grains, characteristic of several other families in the Annulipalpia, is used i n the Dipseudopsidae to collect food materials suspended i n the current. B y adopting the behaviour of burrowing i n soft sediments and extending the openings of their tubes above the substrate, larvae o f Phylocentropus are able to divert a portion o f the current through the buried tube system and remove suspended food particles i n a filter of silken mesh. They have, in effect, duplicated the filter-feeding behaviour of other Annulipalpia, such as Hydropsychidae and Philopotamidae, but have gained additional protection from predators by concealment w i t h i n sedimentary deposits. Six genera are recognized i n the Dipseudopsidae: Protodipseudopsis, Eodipseudopsis, and Limnoecetis from Africa, and Dipseudopsis from Africa and Asia (Marlier 1962); Phylocentropus from eastern North America and Malaysia; and Hyalopsyche from Asia and Australia (Wells and Cartwright 1993). N o representatives now occur i n Europe, but several species of Phylocentropus are known from European Baltic amber deposits of O l i g o c è n e age (Ulmer 1912; Ross 1965); thus, the genus Phylocentropus is at least 25-35 m i l l i o n years old. Observations by Marlier (1952) and Gibbs (1968) show that the tubes of Dipseudopsis larvae in Africa and Asia are exposed on submerged logs and other surfaces, not unlike exposed tubes o f the Psychomyiidae and Ecnomidae. Behaviour of other larvae has been elucidated through studies by Gibbs (1968) on Protodipseudopsis i n Africa, and by Wallace et al. (1976) on Phylocentropus in North America. Located within the tube, the larva draws a current of water through i t by means of abdominal undulation; with the claws o f the anal prolegs fixed i n the lining o f the tube, the long and flexible prolegs allow the abdomen to undulate freely, creating a current (Gibbs 1968, f i g . 3). I n the African genus Protodipseudopsis, the abdomen is broadened into a lateral flange that enhances the ventilation effect (Scott 1985); this flange is not evident in Phylocentropus but a lateral fringe of single filaments does occur. Larvae o f Phylocentropus frequently occur i n lakes, as do certain o f the African dipseudopsids, where the ability to generate a current from within the tube is probably important for respiration as well as for feeding. 118

5 F a m i l y Dipseudopsidae Larval morphology is similar i n all genera in which the immature stages are known, evidently shaped to a large extent by the tube-dwelling existence. Larvae are long and slender (Fig. 5.1 A; Scott 1985, fig. 24.16; Wells and Cartwright 1993, figs. 7, 8, 12-20), rather like large chironomids with legs. The labium is extended into a long ligula, presumably to facilitate application of silk to the interior of the tube; labial palpi are lacking. The mandibles are broad, and both bear large setal brushes on the mesal surface, suitable for removing food particles from the filter net. The legs are unique among Trichoptera, w i t h broad flattened tarsi bearing many short setae. The fore trochantin is fused w i t h the pleuron, lacking the separating suture o f the Psychomyiidae, and similar to the Polycentropodidae. The abdomen bears long, slender anal prolegs, and prominent lobes resembling anal papillae. Recent taxonomic history i n this family provides an unusual example of systematic congruence between different stages of the life cycle. Strong similarities in the highly specialized features of larval morphology and behaviour led Ross and Gibbs (1973) to propose that Phylocentropus be placed along w i t h Dipseudopsis and Protodipseudopsis i n the subfamily Dipseudopsinae (Polycentropodidae), later Dipseudopsidae. None the less, similarities i n the adults o f Phylocentropus and Hyalopsyche led Schmid (1979, 1980, 1983) to discount this position and to propose assignment o f Phylocentropus to the Hyalopsychidae. Recently, however, discovery o f the first larva o f Hyalopsyche by Wells and Cartwright (1993) i n Australia revealed the specialized larval morphology and behaviour o f Hyalopsyche and Phylocentropus to be nearly identical - so nearly so that they proposed suppression o f the name Hyalopsychidae as a synonym of Dipseudopsidae. Convergent burrowing behaviour is k n o w n in some South American Hydropsychidae, in which U-shaped filter tubes are also embedded i n sandy substrates (Sattler and Kracht 1963).

119

5.1

Genus Phylocentropus

D I S T R I B U T I O N A N D S P E C I E S The genus Phylocentropus comprises five species in North America and a single one from Malaysia; the North American species occur within the eastern half of the continent (Ross 1965; Schuster and Hamilton 1984). Larvae have been described for two species: P. lucidus (Hagen) by Sibley (1926); and P. placidus (Banks) by Vorhies (1909, as P. maximus). We have associated material for these two and for P. carolinus Carpenter. M O R P H O L O G Y Phylocentropus larvae are distinguished by characters o f the legs ( A ) : all tarsi are flattened and paddle-like; tarsal claws o f the middle and hind legs are short and stout; tibiae o f all legs are short. The tip of the labium is very long ( B ) . Filaments on the side o f the abdomen are single, and not bifid as in the Integripalpia (Kerr and Wiggins, 1995). Length of larva up to 20 m m . R E T R E A T Larvae o f this genus construct branching tubes o f silk covered w i t h sand (D) in sedimentary deposits in lakes and along margins of sandy streams. The upstream end of the tube extends above the substrate, and descends more or less vertically into the sand. Diverging from this main tube is a lateral branch that opens at the surface, usually downstream from the first opening, and bears a bulbous portion near its junction with the main tube; w i t h i n the bulb is a sack-shaped capture net o f silk strands randomly arranged (Wallace et al. 1976). Extensive systems o f tubes are often found with more than one bulbous side-branch, but usually only the upper one is functional and the others are sealed off at the base o f their junction w i t h the main tube. Total length o f a single main tube up to at least 16 cm. B I O L O G Y The larva is positioned within the main vertical tube between the open end and the lateral branch (Wallace et al. 1976). Observations on similar tubes of the African Protodipseudopsis (Gibbs 1968) indicate that a current of water enters through the upstream opening and passes through the bulb to the downstream surface opening; abdominal undulation by the larva probably provides much o f the current propulsion w i t h i n the tube. Phylocentropus larvae ingest mainly fine particles w i t h some vascular plant pieces and diatoms (Wallace et al. 1976); it is presumed that the larva enters the sidebranch periodically to remove these particles from the net, and setal brushes on the mandibles (C) and maxillae are probably adapted for this function. R E M A R K S Taxonomy o f adults o f the North American species was summarized by Schuster and Hamilton (1984) and by Armitage and Hamilton (1990); distribution maps were also provided.

Phylocentropus carolinus (South Carolina, Oconee Co., 18-19 M a y 1970, ROM 700350) A , larva, lateral x l 4 , fore and middle tarsi and claws enlarged; B, head, pro- and mesonotum, dorsal; c, mandibles, ventral; D, dwelling tube in sediment, ends projecting, x2, arrows indicating direction o f current 120

Dipseudopsidae: Phylocentropus 5.1

121

This page intentionally left blank

6 Family Ecnomidae

The family Ecnomidae is represented in most faunal regions of the w o r l d ; in North America only the genus Austrotinodes from southern Texas is known. Species o f Austrotinodes occur through M e x i c o and Central America, and also in Chile (Flint 1973); the genus is closely related to Ecnomina of Australia and N e w Zealand. Presumably, the Ecnomidae reached North America by way of Gondwanian continents of the southern hemisphere, and not from Eurasia where the genus Ecnomus occurs. Larvae of the Ecnomidae share characters with the Polycentropodidae and Psychomyiidae, and were for some time treated as a subfamily of the latter group; their relationships were investigated by Lepneva (1956). A principal distinction of larvae of the Ecnomidae is the sclerotized meso- and metanota, otherwise confined to the Hydropsychidae and Hydroptilidae. However, i n the African genus Parecnomina, only the pronotum is sclerotized, as i t is in the Polycentropodidae (Marlier 1962; Scott 1985). I n other characters, the head in Ecnomidae has a broadly triangular ventral apotome, and the submental sclerites are fused as a single lightly sclerotized plate, much as in the Polycentropodidae. The labial palpi i n Ecnomidae are slender and separate from the labium, and the maxillary lobe is also slender and elongate. The mandibles are elongate and lack a mesal cluster of setae. The legs are similar i n size; the fore trochantin is unusually long and pointed, continuous w i t h the episternum as i n the Polycentropodidae, and without the dividing suture of the Psychomyiidae. The abdomen has a mid-lateral line of many setae in Ecnomus, but these setae are lacking i n Austrotinodes; the basal segment o f the anal proleg is short, and the claw bears small teeth on the ventral curved edge. Larvae construct silken tubes covered with sand grains on rocks i n the riffle areas o f streams and along wave-washed lake shorelines.

123

6.1

Austrotinodes

D I S T R I B U T I O N AND S P E C I E S This is a Neotropical genus, widely distributed in Chile and in Central America through Panama, Guatemala, Belize, and M e x i c o (Flint 1973) to southern Texas. Occurrence of Austrotinodes larvae in Texas has been known for some time (Waltz and McCafferty 1983); adult and larval stages of Austrotinodes n.sp. are described by Bowles (in press). Morphology of the larva and pupa of a Neotropical species was described by Flint (1973). M O R P H O L O G Y The head is unusually long and slender, almost equal to the thorax in length, and flattened ventrally (B); a sharp carina extends along each side of the head. The notum of each thoracic segment is sclerotized, and a median ecdysial line is present on each one; the pronotum lacks a sulcus or thickening along the posterior margin. The prothoracic trochantin (D) is longer than the coxa, strongly depressed, and paddle-like; a very stout black seta arises from the distal end of the coxa (A). The abdomen lacks secondary setae although long scale hairs occur laterally on the head and thorax, and on abdominal segments (A, B). A sclerite is lacking on the dorsum of segment IX. The anal prolegs are prominent, and the anal claws are almost as large as in the Rhyacophilidae (A). Anal papillae are present. Length o f larva up to 8 m m . Larvae of Austrotinodes resemble those of the Philopotamidae in general form, but the labrum is fully sclerotized and the pronotum lacks a black posterior border. RETREAT

Larvae construct fixed tubes of rock fragments held together by silk.

BIOLOGY

Larvae live on rocks i n streams.

R E M A R K S Taxonomy of Austrotinodes adults was summarized by Flint (1973). A larva was made available for study here by D . E . Bowles.

Austrotinodes

sp. (Texas, Bandera Co., 9 M a y 1992, ROM)

A, larva, lateral x l 6 ; B, head and thorax, dorsal; C, anterior part of head, ventral; D, fore trochantin, dorsal 124

Ecnomidae: Austrotinodes 6.1

125

7 Family Hydropsychidae

The Hydropsychidae are a large and dominant family o f caddisflies l i v i n g i n running waters over much o f the world; a few species occur along wave-washed shorelines o f lakes. Ten genera are known in the Nearctic region, and usually several of them are represented i n a single stream system, their larvae distributed over the longitudinal range o f lotie habitats according to differing requirements of temperature, current speed, and oxygen saturation (e.g. Wiggins and Mackay 1978). Hydropsychid caddisflies are extremely important in the ecology o f running-water systems because o f their ubiquitous occurrence, abundance, and large biomass. Approximately 145 species are recorded in Canada and the United States. Keys for identification o f adults were provided by Ross (1944) and N i m m o (1987), among others. Hydropsychid larvae are distinguished from all others by sclerotization o f the dorsum o f each thoracic segment, combined w i t h branched gills on the ventral surface o f the abdomen and last two thoracic segments, and usually by a tuft o f long setae near the apex o f each anal proleg. The sclerotized plates o f the mesonotum and metanotum do not have a median dorsal ecdysial line, although the line does occur on the pronotal plate; i n some subfamilies the last t w o thoracic notai sclerites have a transverse ecdysial suture. I n some genera, and perhaps a l l , first instars lack gills, and might then be confused w i t h final instars o f the Hydroptilidae; but first instars o f Hydropsychidae can usually be distinguished by the lobate hind margin o f the metanotal plate (Fig. 7.5A). Characters o f the gills and other structures diagnostic for hydropsychid genera are not fully developed i n early instars. Larvae have dense brushes o f setae at each side o f the labrum that probably function i n feeding. On the venter o f segment VIII i n most genera and IX i n all genera there is a pair o f sclerites w i t h stout, backward-directed setae that probably serve i n locomotion. Secondary setae are richly developed i n the Hydropsychidae, and serve a useful role as taxonomic characters. A lexicon o f setal types developed by Patricia Schefter has been applied to the problem o f larval taxonomy for species o f Hydropsyche

(Schefter and W i g -

gins 1986). Chaetotaxy provides characters that are more consistent than the colour patterns o f sclerotized parts, and also capable o f finer resolution among species and higher taxa. 126

7 Family Hydropsychidae Hydropsychid larvae are best k n o w n for the elegant silken capture nets they spin to strain food from the current (Figs. 7.5G, 7.7F). Studies in Europe (Sattler 1958, 1963b) and North America (Wallace 1975a, b) have revealed intricate details o f the net-spinning behaviour by which larvae in different genera weave meshes o f certain dimensions, specializing their filtering for food particles o f a particular size range (Wallace and Malas 1976b, f i g . 1). Larvae in the subfamily Arctopsychinae live in the strong currents of cold streams, spin the largest meshes, and feed on other insects as w e l l as fine detritus. Larvae in the Macronematinae occur in slow currents o f downstream sites, and spin nets w i t h the smallest mesh size to filter small particles suspended in the current. Larvae o f Hydropsychinae occupy sites between these two extremes, and spin meshes o f intermediate size range. Food studies on larvae in several genera indicate that algae, fine organic particles, and small aquatic invertebrates are ingested. The biology and larval taxonomy of Hydropsychidae in Wisconsin was studied by Schmude and Hilsenhoff (1986). Larvae o f Hydropsyche

are able to produce sound by stridulating (Johnstone 1964; Jan-

sson and Vuoristo 1979). A ridged area on each side of the ventral surface o f the head (e.g. Fig. 7 . 6 D ) is rubbed over a raised tubercle on the dorsal edge of each femur (e.g. F i g . 7.6B). When stridulating, the fore legs are anchored firmly on the retreat or net, and the head is thrust rapidly forward and back, engaging the file and scraper mechanism on both sides simultaneously. A l l four subfamilies of the Hydropsychidae are represented on this continent; following are the Nearctic genera i n each subfamily and a summary of larval characters. A R C T O P S Y C H I N A E : Arctopsyche,

Parapsyche

Head tending to be quadrate i n dorsal

aspect; frontoclypeal sutures sigmoid, short cuticular inflection on frontoclypeal apotome near eyes; mandibles w i t h teeth grouped near apex; ventral apotome not subdivided, thereby separating genae completely along the mid-ventral ecdysial line; ventral transverse ridges o f head broken by longitudinal gaps, the roughened area ovoid in outline; meso- and metanotal plates subdivided by transverse ecdysial line; abdominal and thoracic gills w i t h all branches arising from apex o f central stalk; lateral gills similar to ventral gills; sclerites on venter VIII short and wide. This group is ranked as a separate family, Arctopsychidae, by some authors (e.g. Lepneva 1964; Schmid 1968a), but I share the view taken by most North American workers (e.g. Ross 1944, 1967; Flint 1974a; Wallace 1975a) that familial status for the Arctopsychinae is inconsistent w i t h other family and subfamily rankings i n Trichoptera. M o r e over, the t w o taxa are sister groups, and any real advantage in separating them has yet to be demonstrated. The group is considered to be the most primitive i n the Hydropsychidae. D I P L E C T R O N I N A E : Diplectrona,

Homoplectra,

Oropsyche

Head tending to be glo-

bose; frontoclypeal sutures sigmoid or nearly so; mandibles w i t h teeth distributed along mesal edges; ventral apotome o f head in two parts, both parts approximately the same length; ventral ridges of head usually broken by longitudinal gaps, the roughened area broadly tapered posteriorly in outline; meso- and metanotal plates subdivided by transverse ecdysial line; abdominal and thoracic gills sparsely branched, some branches arising along central stalk, most arising from apex o f stalk; lateral gills, when present, reduced to short lobes; sclerites on venter v m ovoid.

127

7 Family Hydropsychidae The larva of Oropsyche, known only by one species from North Carolina, is unknown (Huryn 1989). HYDROPSYCHINAE: Cheumatopsyche, Hydropsyche, Potamyia, Smicridea Head tending to be quadrate in dorsal aspect, the dorsum flattened; frontoclypeal sutures generally more nearly straight than sigmoid; mandibles with teeth distributed along mesal edges; ventral apotome in two parts, the posterior part minute; ventral ridges of head not broken, the entire roughened area generally rectangular; fore trochantin frequently forked; meso- and metanotal plates not subdivided transversely; abdominal and thoracic gills with lateral branches numerous; lateral gills when present reduced to short lobes; sclerites on venter vin triangular and elongate, sometimes fused. Another genus, Plectropsyche, allied to Cheumatopsyche, occurs in Mexico (Ross 1947), but has not been recorded within the Nearctic region.

Leptonema, Macrostemum Mandibles with teeth distributed along mesal edges; ventral apotome in two parts, posterior part minute or lacking; mesoand metanotal plates not subdivided transversely; abdominal and thoracic gills featherlike, apical and lateral branches equally dense, lateral gills similar to ventral gills; sclerites lacking on venter vin.

M A C R O N E M AT IN A E :

Key to Genera 1

12

Ventral surface of head with genae entirely separated by ventral apotome (Fig. 7.1c) (subfamily Arctopsychinae) 2 Ventral surface of head with genae at least partly contiguous (Figs. 7.3c, 7.9G) 3

2

(1) Dorsum of most abdominal segments with tuft of several slender setae and/or scale-hairs in sal and sa3 positions (Fig. 7.8B); ventral apotome of head usually but not always roughly rectangular (Fig. 7.8D). Widespread 7.8 Parapsyche Dorsum of most abdominal segments with only one long seta in sal and sa3 positions, frequently with one or two shorter ones as well, but not a tuft as above (Fig. 7.1E); ventral apotome of head narrowed posteriorly (Fig. 7.1c). Widespread 7.1 Aretopsyche

3

(1) Ventral apotome of head in two parts, anterior and posterior, posterior ventral apotome at least half as long as median ecdysial line separating the two parts (Fig. 7.4D) (subfamily Diplectroninae) 4 Ventral apotome of head usually in two parts, but posterior ventral apotome reduced and much less than half as long as median ecdysial line (Fig. 7.9G), or posterior apotome lacking (Fig. 7.7E) 5

1 See qualifications under Use of Keys, p. 7. 2 Larva unknown for Oropsyche from North Carolina. 128

7 Family Hydropsychidae 4

(3) Pronotum with transverse sulcus constricting posterior one-third or so of pronotum from anterior two-thirds (Fig. 7.4A, F). Eastern and western 7.4 Homoplectra Pronotum lacking transverse sulcus as above, constricted only slightly at posterior border (Fig. 7.3A, B). Eastern and western 7.3 Diplectrona

5

(3) Abdominal gills consisting of elongate central stalk with numerous filaments arising more or less uniformly along entire length (Fig. 7.6A); fore trochantin never forked (Fig. 7.7B) (subfamily Macronematinae) 6 Abdominal gills with central stalk, but filaments fewer than above and not arising uniformly, frequently in apical tuft with fewer gill filaments arising from basal part of central stalk (Fig. 7.2A); fore trochantin usually forked (Fig. 7.5B) (subfamily Hydropsychinae) 7

6

(5) Tibia and tarsus of fore leg with dense setal fringe (Fig. 7.7B); dorsum of head 7.7 Macrostemum flattened and with sharp carina (Fig. 7.7D). Eastern Tibia and tarsus of fore leg lacking dense setal fringe (Fig. 7.6A); dorsum of head without sharp carina (Fig. 7.6E). Southeastern Texas 7.6 Leptonema

7

(5) Submentum with anterior border entire (Fig. 7.10c), or with broad, shallow emargination; dorsum of abdomen with only closely spaced, flattened scale hairs, other setal types lacking (Fig. 7.10A). Southwestern 7.10 Smicridea Anterior border of submentum with pronounced median division (Fig. 7.5F); dorsum of abdomen with hair-like setae only, or mingled with clavate or flattened scale hairs (Fig. 7.5A) 8

8

(7) Venter of prothorax with pair of prominent sclerites in intersegmental fold posterior to prosternai plate (Fig. 7.5c), anterior margin of frontoclypeus lacking small median notch (Fig. 7.5E). Widespread 7.5 Hydropsyche Venter of prothorax with pair of sclerites, usually minute, in intersegmental fold posterior to lateral corners of prosternai plate (Fig. 7.2B); if these sclerites are larger than illustrated, anterior border of frontoclypeus usually with small median notch (Fig. 7.2D) 9

9

(8) Anterior ventral apotome of head with prominent anteromedian protuberance (Fig. 7.9G); lateral margin of mandibles flanged (Fig. 7.9E); abdomen with divided hair-like setae dorsally, scale hairs laterally; fore trochantin forked or not forked (Fig. 7.9B, C). Central and eastern 7.9 Potamyia Anterior ventral apotome of head without anteromedian protuberance (Fig. 7.2E); lateral margin of mandibles not flanged (Fig. 7.2c); abdomen with only undivided hair-like setae dorsally and laterally, without scale hairs; fore trochantin forked (Fig. 7.2A). Widespread 7.2 Cheumatopsyche 129

7.1 G e n u s A r c t o p s y c h e D I S T R I B U T I O N AND S P E C I E S Arctopsyche is a genus o f some 17 species widely distributed in boreal and montane sections of the Oriental, Palaearctic, and Nearctic regions (Schmid 1968a). Four species are known in North America: A. californien L i n g from California; A. grandis (Banks), widespread and common in the west from New M e x ico and California to Alberta and British Columbia, and recorded also from northern Q u é b e c ; A. irrorata Banks from the southeast; A. ladogensis (Kolenati), Holarctic through northern Europe, Asia, and Canada to Maine and New Hampshire. Larvae have been described for A. grandis (Smith 1968a), and for A. irrorata and A. ladogensis (Flint 1961a). We have associated material for A. grandis and ladogensis, and many other series of larvae. M O R P H O L O G Y Larvae of the subfamily Arctopsychinae, w i t h the two genera Arctopsyche and Parapsyche, are readily separated from all others because the ventral apotome of the head separates the genae entirely; other characters shared by the two genera are outlined under the subfamily. I n larvae o f Arctopsyche the ventral apotome is narrowed posteriorly (C), but the same condition holds in at least one species of Parapsyche (q.v.). Therefore, i t is necessary to make the further distinction that larvae now known in Arctopsyche have only a single long seta i n the sal and sa3 positions of most abdominal segments, although there may be one or two shorter ones as well (E). Most larvae of Arctopsyche have brownish yellow sclerites and a pale median dorsal band on the head and thorax (B); they have elongate scale-hairs on the abdominal terga (A, E). Length o f larva up to 30 m m . R E T R E A T Observations on the larval retreat and capture net o f A. irrorata and A. grandis (Wallace 1975a) indicate that they are essentially similar to those of Hydropsyche and Diplectrona, except that mesh sizes in the nets of Arctopsyche species are the largest known i n the family. B I O L O G Y Larvae inhabit cold, running waters, where retreats are located in strong currents. Information on life cycles was given by Flint (1961a), M e c o m (1972b), and Smith (1968a). Available data indicate that Arctopsyche larvae feed mainly on other aquatic insects (Mecom 1972a, b; Wallace 1975a); capture nets are maintained throughout the winter by A. irrorata i n Georgia (Wallace 1975a). R E M A R K S Taxonomy of adults has been summarized by Schmid (1968a), and o f adults and larvae o f western North American species by Givens and Smith (1980).

Arctopsyche grandis (Wyoming, Yellowstone Nat. Park, 12 July 1961, ROM) A, larva, lateral x l 3 ; B, head, dorsal; C, head, ventral; D, segments VIII and IX w i t h bases of anal prolegs, ventral; E, abdominal segment, lateral 130

Hydropsychidae: Arctopsyche 7.1

131

7.2 G e n u s C h e u m a t o p s y e h e D I S T R I B U T I O N A N D S P E C I E S Cheumatopsyehe is a large genus represented on all continents except South America. M o r e than 40 species are now known in Canada and the United States, and the group is common almost everywhere. Larval stages have been associated for several species (Ross 1944; Schefter and W i g gins 1987; M . H . Smith 1984), but diagnostic characters for their separation have been difficult to find. We have associated material for 12 species. M O R P H O L O G Y North American larvae of Cheumatopsyehe tend to be uniformly dark on the head without the varied colour patterns o f Hydropsyche larvae. Sclerites immediately posterior to the transverse prosternai sclerite are very small i n most Cheumatopsyehe ( B ) ; but i n the larva o f at least one species, C. etrona Ross, these sclerites are unusually large, leading to possible confusion with Hydropsyche. Most Cheumatopsyehe, including C. etrona, are distinctive, however, i n having a median notch on the anterior margin of the frontoclypeal apotome ( D ) , although the notch is absent in some species. Larvae o f Cheumatopsyehe lack scale-hairs on the abdomen, and have only hair-like setae ( A ) . Length o f larva up to 13 m m . R E T R E A T Fremling (1960) described the capture net o f C. campyla Ross as more voluminous and flimsy than that o f Hydropsyche orris, and therefore suited for relatively weaker currents. B I O L O G Y According to Ross, larvae of Cheumatopsyehe tend to be more dominant i n warmer streams than Hydropsyche (1959), and to be successful in streams too polluted for most other caddisflies (1944). Larvae o f C. campyla were found to be more abundant in slower currents than H. orris Ross, and conversely in stronger currents (Fremling 1960). Cheumatopsyehe larvae have also been found to depths o f 20 cm or more i n the interstitial habitat o f stream beds (Williams and Hynes 1974). We collected larvae o f Cheumatopsyehe along the shoreline of Lake Winnipegosis, Manitoba, together with Hydropsyche altemans. Food o f Cheumatopsyehe larvae in a small Pennsylvania stream was found to be largely algae and animals, w i t h a small detrital component (Coffman et al. 1971). Two generations per year were reported in a Texas river for C. lasia Ross and C. campyla (Cloud and Stewart 1974). R E M A R K S Taxonomic data for adults of the North American species were provided by Gordon (1974).

Cheumatopsyehe pettiti (Ohio, Knox Co., A u g . 1968, ROM) A , larva, lateral x26; B, prothorax, ventral; c, right mandible, dorsal; D, head, dorsal; E, head, ventral; F, segments v m and IX, ventral 132

Hydropsychidae: Cheumatopsyche 7.2

133

7.3 G e n u s D i p l e c t r o n a D I S T R I B U T I O N AND S P E C I E S This genus is represented in most faunal regions but has not been recorded from tropical Africa or from South America. Four species are known in North America north of M e x i c o : D. modesta Banks, widespread throughout the east to South Dakota and Oklahoma; D. metaqui Ross i n Georgia, Tennessee, Kentucky, Indiana, and Illinois (Ross 1970); D. rossi Morse in Louisiana; and D. califomica Banks from California (Flint 1966). Diagnostic data are available for the larva o f D. modesta (Ross 1944, 1959), for D. metaqui (Ross 1944 and 1959 as Hydropsychid Genus A ; Ross 1970), and for D. rossi (Morse and Barr 1990). M O R P H O L O G Y The larvae known for most North American species are typical members o f the Diplectroninae i n having the posterior ventral apotome of the head well developed (C). But the larva o f D. metaqui is so grossly different from any other of our hydropsychids in the large thumb-like process on the left mandible (F, G) that it was assigned tentatively to an unknown genus, Hydropsychid Genus A (Ross 1944, 1959), until finally shown to belong to a new species, Diplectrona metaqui (Ross 1970). This species also differs from D. modesta in having a prominent notch on the anterior border of the frontoclypeal apotome (F). Both species are, however, consistent in lacking a transverse sulcus on the pronotum (B), and thus can be distinguished from the other diplectronine genera i n which the sulcus is present. Sclerites of the head and thorax are reddish brown i n colour. Larvae o f Diplectrona have elongate scale-hairs on the abdominal segments (A). Length of larva up to 15 m m . R E T R E A T According to Sattler (1963a) the retreat and capture net of the European Diplectrona fel ix M c L . are constructed essentially as i n Hydropsyche, although the retreat is almost entirely of plant materials and without the considerable proportion of sand utilized by Hydropsyche larvae. B I O L O G Y Larvae live in rapid portions o f small, cool streams. Mackay (1968) found them i n moss on submerged rocks and in leaf packs; the species (prob. D. modesta) was univoltine, eggs hatching in late summer and autumn, and larvae overwintering to mature in early summer. Gut contents o f D. modesta analysed by Ross and Wallace (1983) were primarily fine detritus and animal material.

Diplectrona prob. modesta (Pennsylvania, L y c o m i n g Co., 7 M a y 1968, ROM) A, larva, lateral x l 5 ; B, pronotum, dorsal; C, head, ventral; D, head, dorsal; E, segments v i l i and IX, ventral D. metaqui (Tennessee, Franklin Co., 14-15 May, ROM 700337) F, head, dorsal; G, left mandible, lateral 134

Hydropsychidae: Diplectrona 7.3

135

7.4

Genus H o m o p l e c t r a

D I S T R I B U T I O N AND S P E C I E S

This genus is confined to North America, but as now

defined comprises species from eastern as well as western parts o f the continent, in accordance with the proposal that Aphropsyche

is a junior synonym o f Homoplectra

(Weaver

1985). Eight species of Homoplectra

western species o f Homoplectra

ern species o f Homoplectra,

H. monticola

are known in western North America; the larva o f one has been described (Wiggins 1977). Larvae o f three east-

two o f them formerly assigned to Aphropsyche,

are known:

(Flint) (Weaver et al. 1979); H. sp. prob. doringa (Milne) (Wiggins 1977); H.

flinti Weaver (Huryn 1989, larva described as Oropsychel

by Wiggins 1977).

M O R P H O L O G Y Larvae o f Homoplectra can be distinguished from Diplectrona (q.v.) by a transverse sulcus on the pronotum which constricts the posterior one-third from the anterior two-thirds ( F ) . W i t h i n that diagnosis, the species are not homogeneous in structure: two o f the eastern species, H. doringa and monticola, have a pronounced emargination on the left side o f the anterior border of the frontoclypeal apotome ( E ) ; in a third eastern species, H. flinti, the frontoclypeal apotome is symmetrical, as it is in Homoplectra larvae known from western N o r t h America. The western larvae have stout setae subdivided into a cluster o f flattened lobes on the mesal face o f the middle and hind femora (B), while the eastern larvae have stout feathered setae on the femora (G). These diagnostic characters were outlined i n the form o f a key by Huryn (1989). R E T R E A T Larval retreats o f typical hydropsychid structure were described for H. monticola (Weaver et al. 1979), and for H flinti (Huryn 1989). B I O L O G Y The larvae o f Homoplectra now known occur in intermittent spring seeps, usually in the headwaters o f mountain streams (Huryn 1989). R E M A R K S Diagnostic characters for males o f five western species o f Homoplectra were provided by Denning (1956). Taxonomic data for adults o f the eastern species were provided for H. doringa by Ross (1944), H. monticola by Flint (1965), and H. flinti by Weaver (1985). Some specimens were provided for study by O.S. Flint.

Homoplectra sp. (Oregon, L i n n Co., 22 June 1968, ROM) A, larva, lateral x l 9 ; B, middle leg, mesal, one seta enlarged; C, head, dorsal; D, head, ventral Homoplectra prob. doringa (Arkansas, Logan Co., 16 M a y 1958, USNM) E, head, dorsal; F, pronotum, dorsal; G, middle leg, mesal, one seta enlarged Homoplectra flinti (North Carolina, Macon Co., 8 June 1961, USNM) H, segments v i n and IX w i t h bases o f anal prolegs, ventral 136

Hydropsychidae: Homoplectra 7.4

137

7.5 G e n u s H y d r o p s y c h e D I S T R I B U T I O N AND S P E C I E S Hydropsyche, the largest genus in the family, occurs on all continents except South America. M o r e than 70 species are now known in North America north of M e x i c o . Larval stages have been associated for many species by Ross (1944), Schuster and Etnier (1978), Schefter and Wiggins (1986), Smith (1979), and Smith and Lehmkuhl (1980). M O R P H O L O G Y Larvae can be distinguished from other genera o f the Hydropsychinae by the pair of large sclerites in the intersegmental fold posterior to the prosternai plate (c) (but see under Cheumatopsyehe)', the paired sclerites posterior to the prosternai plate are not w e l l developed in early instars. The dorsal ramus of the fore trochantin (B) does not begin to develop until the second instar and becomes larger w i t h successive moults (Siltala 1907a). Colour patterns o f the head exhibit a wide range of interspecific differences (Ross 1944, figs. 346-357; Schuster and Etnier 1978), but species can also be distinguished by setal characters (Schefter and Wiggins 1986). Abdominal segments of Hydropsyche larvae have scale-hairs and hair-like setae (A). Length of larva up to approximately 16.5 m m . R E T R E A T The capture net o f Hydropsyche larvae is usually taut and the perimeter supported by pieces of debris that are themselves stabilized by silken guy-lines (G; Fremling 1960, f i g . 8). Nets are not maintained during low winter temperatures at the latitude o f southern Ontario (Fuller and Mackay 1980). B I O L O G Y Most Hydropsyche are restricted to running waters, some species in larger rivers, others restricted to small streams; but larvae o f H. al te mans Walker and H. confusa Walker occur on rocks along the edge of several of the Great Lakes (Sykora et al. 1981). L i f e cycles o f Hydropsyche species have been studied extensively (e.g. Fremling 1960; Mackay 1979, 1984). Food o f Hydropsyche larvae has been analysed many times, with algae, detritus, and animals found to be ingested in varying proportions at different seasons (e.g. Coffman et al. 1971; Fuller and Mackay 1980; M e c o m 1972a). R E M A R K S Proposals have been made to assign the morosa species group to the African genus Symphitopsyche, subgenus Ceratopsyche (Ross and Unzicker 1977; Schuster and Etnier 1978); and Nielsen (1981) proposed that Ceratopsyche be raised to generic level. Because these taxonomic proposals were based on comparative study o f no more than half of the generic groups i n the subfamily Hydropsychinae, a subsequent proposal was made (Schefter et al. 1986) to treat Ceratopsyche as a subgenus o f Hydropsyche, thereby retaining the traditional status of Hydropsyche, at least until global assessment of the group has been made.

Hydropsyche morosa (Ontario, Peel Co., 15 Sept. 1970, ROM) A, larva, lateral x l 5 ; B, fore trochantin, lateral; c, prothorax, ventral; D, segments VIII and IX, ventral; E, head, dorsal; F, head, ventral; G, retreat and capture net 138

Hydropsychidae: Hydropsyche 7.5

139

7.6 Genus L e p t o n e m a DISTRIBUTION

A N D SPECIES

Leptonema

is a large genus o f South and Central

America, Africa, and Madagascar; it is widespread in Mexico and one species, L . albovirens (Walker), extends through Central America to southeastern Texas (Flint et al. 1987).

Larval characters for the genus were summarized by Ulmer (1957). Larvae o f New World Leptonema

species have been described by Flint (1964b) and by Flint and Wallace

(1980); larvae o f O l d World species have been described by Marlier (1961, 1962), Scott (1983), and others. The larva o f L . albovirens

was characterized by Flint (1968b). We have

several collections of larvae from M e x i c o . M O R P H O L O G Y Although Leptonema is classified i n the subfamily Macronematinae, larvae show little general similarity to the related North American genus Macrostemum. One diagnostic larval character shared by the two genera is the structure o f the abdominal gills - a central stalk w i t h filaments radiating uniformly throughout its length, and somewhat feather-like i n appearance ( A ) . Larvae are densely covered w i t h short, dark setae, a feature especially noticeable on the abdomen. In the series of Mexican larvae that I studied, there is a single wide sclerite immediately posterior to the prosternai plate (C). A prominent mesal lobe is located on the distal end of the fore coxa, and the scraper on the mesal face o f the fore femur is especially well developed ( B ) . Larval morphology, to the extent that it is known, appears to be congruent in some characters with species groups based on adults (Scott 1983; Flint and Wallace 1980; Flint et al. 1987). Leptonema larvae have acuminate scale-hairs, and hair-like setae are confined to the lateral line ( A ) . Length o f larvae examined up to 25 m m . R E T R E A T Larvae o f Leptonema construct typical hydropsy chid retreats and capture nets (Flint 1968a); the retreat is covered with sand grains, and fastened to a rock. The size o f meshes i n nets constructed by L . columbianum Ulmer ranges from 40.5 to 47.5 microns by 80 to 83.5 microns (Flint and Wallace 1980, figs. 3, 4); these meshes are broadly rectangular, and quite different from the elongate meshes i n nets o f some other macronematines such as Macrostemum (Fig. 7.7F). B I O L O G Y Larvae live in running waters, ranging in size from trickles and tumbling mountain brooks to large lowland rivers (Flint 1964b, 1968a). REMARKS

Taxonomy and distribution o f Leptonema

adults were analysed by Flint et

a l . (1987).

Leptonema sp. (Mexico, Veracruz, 17 Dec. 1948, ROM) A, larva, lateral x l l , g i l l enlarged; B , fore leg, mesal; C, prothorax, ventral; D , head, ventral; E, head, dorsal 140

Hydropsychidae: Leptonenia 7.6

141

7.7 G e n u s M a c r o s t e m u m D I S T R I B U T I O N AND S P E C I E S The genus Macrostemum is represented on all continents except Europe. The Nearctic fauna north of M e x i c o comprises three species widely distributed over the eastern half o f the continent, north at least to Minnesota and Q u é b e c , w i t h a record from Utah. Diagnostic characters for larvae of all three species were given by Ross (1944). We have associated material for M. zebratum (Hagen), as w e l l as many collections o f larvae. M O R P H O L O G Y Larvae o f Macrostemum are distinctive from all other North American genera in the Hydropsychidae, primarily because of the flattened head with a sharp U shaped carina, and a pair o f discrete sclerites at the base o f the labrum (D); also unusual is the dense fringe of setae on the fore tibia and tarsus (B), and the prominent process at the base o f the femur (c). Abdominal segments lack scale hairs, and bear only hair-like setae. Length of larva up to 17.5 m m . R E T R E A T Larval retreats and capture nets of Macrostemum species are among the most highly specialized i n the family (Sattler 1963b, 1968; Wallace 1975b). Larvae o f M. zebratum construct an open-ended chamber o f fine sand and silk (F) situated on rocks to intercept the current. Small organic particles carried by the current are filtered out by a silken net spun across the chamber. The larva rests i n a tubular diverticulum, its head close to the upstream surface o f the net; dense setae on the fore legs and labrum are believed to function as brushes for collecting fine particles from the net. Water also flows through the larval tube, meeting respiratory requirements and carrying away faeces. The flattened head o f Macrostemum larvae is thought to function in restricting openings i n the chamber, thereby controlling the amount and direction of the water passing through (Wallace and Sherberger 1974). Length o f retreat illustrated approximately 15mm. B I O L O G Y These are insects o f larger streams and rivers i n North America. Larvae ingest fine particulate organic matter, phytoplankton, and bacteria, and among the North American Hydropsychidae are the most efficient collectors o f such small particles because of the very small mesh size of their nets - in M. Carolina 5 x 40 microns, w h i c h is onesixth the size o f the finest plankton nets available commercially (Wallace and Sherberger 1974). R E M A R K S Research on the systematics and biology of species o f Macrostemum and Macronema in M e x i c o (Flint and Bueno-Soria 1982) has shown that our Nearctic species have to be assigned to Macrostemum.

Macrostemum zebratum (Ontario, Haliburton Dist., 29 M a y 1967, ROM) A, larva, lateral x l l ; B, fore leg, lateral; C, fore leg, base o f femur, mesal; D, head, dorsal; E, head, ventral; F (same data as above, but Sept. 1975), larval retreat and capture net, ventral, portion o f wall removed, meshes enlarged, arrows indicating direction of waterflow x3 142

Hydropsychidae: Macrostemum 7.7

143

7.8 G e n u s P a r a p s y c h e D I S T R I B U T I O N AND S P E C I E S M o r e than 20 species o f Parapsyche are known in Japan, China, Burma, and the Himalayas as well as N o r t h America. Seven species are known from this continent, five i n the west and two in the east. Larvae have been described for the eastern species P. apicalis (Banks) and P. cardis Ross by Flint (1961a), and for two western species, P almota Ross and P. elsis M i l n e , by Smith (1968a). We have associated material for these four species, and many other collections o f larvae. M O R P H O L O G Y Parapsyche and Arctopsyche constitute the subfamily Arctopsychinae, distinguished primarily by a ventral apotome that separates the genae entirely. I n larvae of several species of Parapsyche the lateral margins of the ventral apotome are parallel for the most part (D), clearly distinct from the convergent margins of this sclerite in Arctopsyche. But i n at least one species, P. elsis, the sclerite is tapered as i n Arctopsyche (Smith 1968a). Consequently, diagnosis for larvae o f Parapsyche must be further qualified to include species w i t h a tuft of several long setae or scale-hairs in the sal and sa3 positions of most abdominal segments (B). The frontoclypeal apotome is wider in Parapsyche (C) than i n Arctopsyche. Sclerites of the head and thorax are usually brown in colour. A b d o m inal segments o f Parapsyche are heavily covered w i t h scale-hairs of varied size (A, B). Length of larva up to 9 m m . R E T R E A T Larvae construct a typical hydropsychid retreat of small stones and pieces o f detritus, and spin a silken capture net. Mesh size o f P. cardis given by Wallace and Malas (1976b) indicates meshes spun by Parapsyche larvae are larger than most other Hydropsychidae except for Arctopsyche. B I O L O G Y Larvae o f Parapsyche are characteristic of small, cold streams, where they construct retreats i n strong currents. Data for the life cycle o f the eastern species were given by Flint (1961a) and Mackay (1969), and for two western species by Smith (1968a) and Givens and Smith (1980). Food of P. apicalis and P cardis larvae was mainly fine detritus and animal material ( D . H . Ross and Wallace 1983). R E M A R K S Taxonomy for the adults has been reviewed by Schmid (1968a), and for adults and larvae o f western N o r t h American species by Givens and Smith (1980).

Parapsyche apicalis (Virginia, Madison Co., 23 M a y 1970, ROM 700372) A, larva, lateral x l 4 ; B, abdominal segment, lateral; C, head, dorsal; D, head, ventral 144

Hydropsychidae: Parapsyche 7.8

145

7.9 Genus P o t a m y i a D I S T R I B U T I O N AND S P E C I E S The only N o r t h American species in this genus is Potamyia flava (Hagen), an inhabitant of larger rivers over much o f the eastern and central United States from Virginia and Alabama through Minnesota and South Dakota to M o n tana and Texas. Species o f Potamyia occur in China (Martynov 1930; Schmid 1965), but no others are known. Diagnostic features for the larva of P. flava were given by Ross (1944, 1959). We have several series o f larvae. M O R P H O L O G Y Larvae of Potamyia are generally similar to those o f other Hydropsychinae, but in collections we have examined the fore trochantin ranges from a simple, unforked condition (C) through intermediates to a forked condition (A, B); the conditions illustrated are all from a single series of 18 specimens. Potamyia larvae with a forked fore trochantin could, then, be confused w i t h Cheumatopsyehe, but other characters in the key should effectively separate the two. The head and thorax are light yellowish brown in colour, w i t h few distinctive markings. Each mandible bears a prominent lateral flange (E, F). A b d o m i n a l segments bear mostly hair-like setae, with some small clavate scale-hairs (A). Length o f larva up to 14.5 m m . R E T R E A T Fremling (1960) described the capture net of P. flava as a loose, voluminous structure, similar to nets of Cheumatopsyehe campyla', both partially collapsed when the substrate was removed from water. B I O L O G Y Larvae of Potamyia are characteristic of large, relatively warm rivers. I n the upper Mississippi River, where Fremling (1960) studied the biology o f P. flava, the greatest concentrations of larval nets were on rocks in sandy, silt-free bottom materials. Larvae of P. flava and of Cheumatopsyehe campyla were relatively more abundant i n sites w i t h slower current than those o f Hydropsyche orris, which were dominant in stronger currents.

Potamyia flava (South Dakota, Yankton Co., Feb.-July 1968, ROM) A, larva, lateral x l 6 ; B, forked fore trochantin of another larva, lateral; C, fore trochantin of another larva showing vestigial dorsal ramus, lateral; D, fore leg showing scraper on femur, mesal; E, right mandible, dorsal; F, head, dorsal: G, head, ventral; H, segments VIII and IX, ventral 146

Hydropsychidae: Potamyia 7.9

147

7.10

Genus S m i e r i d e a

D I S T R I B U T I O N AND S P E C I E S Species o f Smieridea occur in South and Central America and the major islands of the Antilles, and in the southwestern United States. Four species are k n o w n north of M e x i c o , within the area bounded by Texas, Oklahoma, Colorado, and California. Diagnostic characters for the larva of S. (S.) fasciatella M c L . were given by Ross (1944); Flint (1974a) described the larva and pupa of that species and identified larvae o f two other Nearctic species, S. (Rhyacophylax) dispar (Banks) and S. (Rhyacophylax) signata (Banks). We have larvae for species i n both subgenera. M O R P H O L O G Y The fore trochantin is simple and not bifurcate (B), distinguishing the larvae at once from those of Hydropsyche and Cheumatopsyehe. Larvae in both subgenera of Smieridea are distinguished by having only closely spaced, flattened scale hairs (A) on the dorsum of the abdomen; and lacking hair-like setae on the abdominal segments. In the subgenus S. (Smieridea) there is a single, median sclerite on the venter of segment VIII (E), and the frontoclypeus and submentum are entire without a median cleft (D, C); the poststernal sclerites of the prosternum are minute as in most Cheumatopsyehe. Larvae in S. (Rhyacophylax) have two small ventral sclerites on VIII, the submentum is emarginate anteriorly, post-sternal sclerites of the prosternum are lacking, and the anterior margin of the frontoclypeus is notched. Length o f larva up to 9.5 m m . R E T R E A T Smieridea larvae construct a typical hydropsy chid retreat with a capture net extending across the current (Flint 1974a). B I O L O G Y Larvae occur in a wide range of running waters, and are often abundant in streams o f the southwest (Flint 1974a). Observations on Smieridea larvae in a Cuban seepage stream were given by Boto§aneanu and Sykora (1973). R E M A R K S Radiation of species in the Neotropical region (Flint 1974a) suggests that Smieridea functions there as the ecological equivalent o f Hydropsyche and Cheumatopsyehe, both o f which are absent from South America. W i t h penetration into North America, Smieridea has become sympatric w i t h both genera.

Taxonomic data for Nearctic species o f Smieridea were summarized and the tribe Smicrideini (Hydropsychinae) established for the genus by Flint (1974a). Smieridea is rather discordant from other genera of the Hydropsychinae and some workers have suggested that it should not be assigned to that subfamily (e.g. Ulmer 1957; Marlier 1964).

Smieridea (S.) fasciatella (Oklahoma, Johnston Co., 10 M a y 1970, R O M 700326) A, larva, lateral with detail of scale-hairs x22; B, fore trochantin, lateral; C, head, ventral; D, head, dorsal; E, segments vin and IX, ventral 148

Hydropsychidae: Smicridea 7.10

149

8 Family Philopotamidae

The Philopotamidae occur in running waters in all faunal regions o f the world; the three Nearctic genera are common and widespread over much of the continent, w i t h approximately 40 species known north o f M e x i c o . Larvae spin elongate, sack-like nets o f silken mesh to filter fine particulate organic matter from currents, and among all the filter-feeding Trichoptera, philopotamids utilize the finest particles. Larvae usually live on the undersides o f rocks, their nets collapsing as amorphous siltcovered masses when the rock is removed from water. The nets are fastened by the anterior edge to the rock in such a way that they are distended as the current flows through them and the downstream ends move freely (Fig. 8.2F). Beneath the silty coating are the elegantly woven rectangular meshes o f the net, w i t h openings smaller than those for any other net-spinning family in North America (Wallace and Malas 1976a); these authors calculated that i n a single net o f a final-instar larva o f Dolophilodes

distinctus there are over

100 m i l l i o n mesh openings and over 1 k m o f silk strands; series o f grooves i n the opening o f the silk gland are thought to enable the larva to spin simultaneously about 70 of the finest silk strands. A small opening at the downstream end o f each net is large enough to perm i t escape o f the larva, and ensures a current of water through the net for respiration and removal o f faeces when the fine meshes are obstructed with particulate matter. Nets commonly occur i n groups; one larva lives w i t h i n each net and feeds by cleaning the fine particles from the inside w i t h its highly specialized membranous labrum. The membranous labrum (Fig. 8 . I D ) is diagnostic for the family, although in preserved specimens it is often retracted under the anterior edge of the frontoclypeal apotome and is not immediately apparent. Antennae are located at the anterior margin o f the head capsule, but are extremely small (Fig. 8.3B). The head and pronotum are brownish orange i n colour, the pronotum bounded posteriorly by a pronounced black band; meso- and metanota are not sclerotized. Basal setae o f the tarsal claws arise from a slender extension o f each claw (Fig. 8.3A). The abdomen is whitish; gills and lateral fringe are absent, and anal papillae are present. Segment I X lacks a dorsal sclerite. Taxonomy, phyletic relationships, and zoogeographic dispersal o f the Philopotamidae, based largely on evidence from adults, were reviewed by Ross (1956); t w o subfamilies are 150

8 Family recognized, Chimarrinae (Chimarra

Philopotamidae

i n N o r t h America) and Philopotaminae

des and Wormaldia in North America). In the world fauna, Chimarra

{Dolophilo-

contains more spe-

cies than all of the other groups i n the Philopotamidae combined. A review o f taxonomy and distribution o f North American species was provided by Armitage (1991). K e y to G e n e r a * 1

Anterior margin o f frontoclypeal apotome with prominent notch (Fig. 8. I D ) , and coxa o f fore leg w i t h long process arising near distal end (Fig. 8.1c); venter of head w i t h seta no. 18 located at level of posterior edge of ventral apotome (Fig. 8 . I F ) . Widespread

8.1

Chimarra

Anterior margin o f frontoclypeal apotome usually lacking prominent notch, although there may be some asymmetry (Fig. 8.2B), but coxa o f fore leg lacking long process; venter of head w i t h seta no. 18 located approximately half-way 2

between posterior edge o f ventral apotome and occipital foramen (Fig. 8.2E) 2

( 1 ) Fore trochantin projecting freely anteriorly to form elongate, finger-like process (Fig. 8.2c, D ) ; venter o f head w i t h seta no. 18 approximately same thickness as stoutest seta on dorsum o f head (Fig. 8.2E). Widespread

8.2 Dolophilodes

Fore trochantin projecting freely only a short distance, thus forming very short process (Fig. 8.3D, E ) ; venter o f head with seta no. 18 stouter than any seta on dorsum o f head (Fig. 8.3c). Widespread

8.3 Wormaldia

*See qualifications under Use of Keys, p. 7. 151

8.1 Genus C h i m a r r a D I S T R I B U T I O N AND S P E C I E S Chimarra is a large genus represented in all major faunal regions, but for the most part in tropical and warm temperate latitudes. The genus is richly represented in Mexico and Central America, and about 20 species are now k n o w n north of the Rio Grande. Diversity decreases markedly at higher latitudes, but species o f Chimarra are known from Maine, Manitoba, and Montana. A key to larvae of four eastern species was given by Ross (1944); the larva of C. betteni

Denning was described by Edwards and A r n o l d (1961). We have associated material for three species and collections o f larvae from many parts of North America. M O R P H O L O G Y Larvae o f this genus have a prominent, often asymmetrical, notch on the anterior margin of the frontoclypeal apotome (B), but so also do some larvae in Dolophilodes (q.v.) However, the elongate process o f the fore coxa ( C ) is diagnostic for Chimarra. Also distinctive among the three North American genera is the location of ventral head seta no. 18 close to the level o f the posterior tip of the ventral apotome ( F ) . Length of larva up to 12.5 m m . R E T R E A T Some of the nets associated w i t h Chimarra larvae have rectangular meshes similar to those in Dolophilodes, although of somewhat less uniform dimensions; but i n others the strands are irregularly arranged throughout and show no regular mesh structure (Wallace and Malas 1976a). Retreats o f Chimarra were described by Noyes (1914, p i . 38, fig. 1); the nets were rarely found singly, but usually in a row o f five or six, w i t h the average size of one net about 25 m m long by 3 m m in diameter. B I O L O G Y The biology o f C. aterrima Hagen was studied in Ontario by N . E . Williams and Hynes (1973). The species was univoltine and larvae subsisted largely on detritus f i l tered by their capture nets throughout the year, growing rapidly during the summer. Although living on the undersides o f rocks i n riffle areas most of the time, larvae migrated to deeper water in winter and to submerged roots of streamside grasses i n warm weather. In another study, Coffman et al. (1971) found that algae constituted about two-thirds of the material ingested by this species, detritus about one-third, with a small animal component as well. R E M A R K S Two subgenera are represented in North America (Ross 1956): C. {Chimarra) to which most species are assigned, and C. iCurgia) for two southern species. Taxonomy of adults and distribution o f the North American species were reviewed by Armitage (1991).

Chimarra sp. (Ontario, Peel Co., 14 O c t 1951, R O M ) A, larva, lateral x l 7 ; B, head and thorax, dorsal; c, fore coxa, anterior; D, labrum, dorsal; E, segment IX and anal prolegs, showing anal papillae, dorsal; F, head, ventral 152

Philopotamidae: Chimarra 8.1

153

8.2 Genus D o l o p h i l o d e s D I S T R I B U T I O N AND S P E C I E S The genus Dolophilodes is represented i n most major faunal regions. Eight species are known in North America north of M e x i c o , largely restricted to cool streams o f eastern and western montane areas; one species, D. distinctus (Walker), is common and widespread in the east from Newfoundland and Minnesota to Georgia. Some structures o f D. distinctus larvae were illustrated by Ross (1944) and Betten (1934). We have associated larvae for D. distinctus, and series o f Dolophilodes larvae from many localities throughout the continent. M O R P H O L O G Y The anterior margin of the frontoclypeus i n most Dolophilodes larvae is somewhat asymmetrical ( B ) , but is prominently notched i n D. major (Banks) o f eastern montane North America, the only species known in the subgenus D. (Fumonta) (Weaver et al. 1981). This character is shared with larvae o f Chimarra. However, the fore trochantin in all Dolophilodes bears a prominent finger-like process projecting anteriorly (c, D ) , which is distinctive among the North American genera. In contrast to Wormaldia, ventral head seta no. 18 is relatively small ( E ) . The outer edges o f the mandibles are transversely serrate i n at least some species. Length of larva up to 16.5 m m . R E T R E A T Capture nets constructed by larvae o f Dolophilodes distinctus are elongate sacks with extremely fine, narrow meshes, approximately 0.5 x 5.5 microns in final instars; usually the net consists only of a single layer (Wallace and Malas 1976a). The fine meshes are formed by closely spaced slender strands fastened transversely across stouter longitudinal strands ( F ) . Silk strands o f one-third or so o f the net around the upstream opening are arranged randomly, presumably strengthening the mooring to the rock. Nets of final instars range from 25 to 60 m m in length and 2.5 to 4.5 m m i n diameter (Wallace and Malas 1976a). B I O L O G Y Contents o f the fore guts o f D. distinctus i n a Georgia stream were largely fine particulate organic matter and diatoms (Wallace and Malas 1976a). Similar findings were reported by M e c o m (1972b) for another species o f the genus i n Colorado, although vascular plant pieces were also ingested in the autumn. The biology o f D. distinctus was studied i n Ontario by W i l l i a m s and Williams (1981). R E M A R K S Three o f the seven subgenera o f Dolophilodes are represented in North America (Ross 1956); the generic names Sortosa and Trentonius (Ross 1944) are j u n i o r synonyms o f Dolophilodes. Taxonomy and distribution o f adults of the North American species were summarized by Armitage (1991). The eastern species D. distinctus is notable for the wingless females that emerge during winter months (Ross 1944, f i g . 171).

Dolophilodes distinctus (Ontario, Peel Co., 1 Oct. 1970, ROM) A , larva, lateral x l 6 ; B , head and thorax, dorsal; c, fore trochantin, lateral; D , fore trochantin, ventral; E , head, ventral; F, t w o capture nets, w i t h section o f silken mesh enlarged approx. x 1000, arrow indicating direction of current 154

Philopotamidae: Dolophilodes

8.2

155

8.3 G e n u s W o r m a l d i a D I S T R I B U T I O N AND S P E C I E S This genus is represented in all faunal regions except the Australian; approximately 14 Nearctic species are now known north of M e x i c o , most of them western, w i t h one species ranging north to the Yukon. Diagnostic characters were given by Ross (1944) for larvae of two widespread eastern species, W. moesta (Banks) and W. shawnee (Ross). We have associated material for three western species, and series o f larvae from many localities. M O R P H O L O G Y The anterior margin o f the frontoclypeal apotome is symmetrical, but may be either convex (B) or concave. The fore trochantin projects anteriorly as a small, knob-like process (D, E); coxal setae are very stout i n some species. On the ventral surface of the head, seta no. 18 is located approximately half-way between the ventral apotome and the occipital foramen as i n Dolophilodes, but is stouter than any o f the dorsal head setae (C). Length o f larva up to 14.5 m m . R E T R E A T Nets of final instar Wormaldia larvae are evidently constructed of several layers o f mesh; the meshes o f each layer are narrow and rectangular as in Dolophilodes, although slightly smaller - 0.4 x 3.7 microns (Wallace and M a i as 1976a, b). Separate layers o f net are superimposed in such a way that the fine meshes overlay each other at an angle, thereby reducing even further the effective mesh openings. Nets described for European species o f Wormaldia (Nielsen 1942; Philipson 1953b, f i g . 4) were about 35 m m long by 5 m m in diameter. B I O L O G Y Larvae move about freely within their silken retreat, and have been observed cleaning fine organic particles from the inner surface o f the net by short downward strokes of the head w i t h the labrum extended (Philipson 1953b). A western species, W. anilla (Ross), was found to have an emergence period from March to December (Anderson and W o l d 1972). R E M A R K S Wormaldia as defined by Ross (1956) includes species treated under Dolophilus (sensu Ross 1944). Two subgenera are recognized (Ross 1956); most North A m e r i can species are assigned to W. {Wormaldia), but W. mohri Ross is placed in the subgenus W. (Doloclanes). Taxonomy and distribution o f adults o f the North American species were reviewed by Armitage (1991).

Wormaldia

sp. (Arizona, Cochise Co., 24 June 1966, ROM)

A, larva, lateral x23, tarsal claw enlarged; B, head and thorax, dorsal, detail o f antenna; C, head, ventral; D, fore trochantin, lateral; E, fore trochantin, ventral 156

P h i l o p o t a m i d a e : W o r m a l d i a 8.3

157

This page intentionally left blank

9 Family Polycentropodidae

The Polycentropodidae are an important group o f retreat-making Trichoptera in all major faunal regions. The family is widespread over much of North America, where there are six genera w i t h nearly 70 species known north of M e x i c o . In general structure this family shows some similarity to the Psychomyiidae, and in fact the Polycentropodidae have been treated as a subfamily of the Psychomyiidae in some North American works (e.g. Ross 1959; Flint 1964a). The Polycentropodidae are most readily distinguished by the pointed fore trochantin, fused without a separating suture to the episternum (Figs. 9.2A, 9.3A). I n polycentropodid larvae the tip o f the labium is short, extending beyond the anterior margin o f the head little i f at a l l ; labial palpi are present though small (Fig. 9.5c), and the maxillary lobes are elongate; submental sclerites are fused, and the ventral apotome is short and broad. Only the pronotum is sclerotized, and all three pairs o f legs are approximately the same size; tarsal claws lack a basal process, and anal papillae are present i n at least some genera. The basal segment o f the anal proleg is at least as long as the distal, usually longer, and the anal claw is w e l l developed, frequently w i t h slender dorsal accessory hooks; tooth-like points on the curved edge o f the claw provide useful taxonomic distinction for some genera. Larval retreats are fixed in position but are more diverse than in any o f the other retreatmaking families. In filter-feeding genera, such as Neureclipsis

and some

Polycentropus,

the flimsy trumpet-like nets (Fig. 9.3D) are suited only to gentle currents without turbulence. Larval retreats in the other North American polycentropodid genera are essentially short fixed tubes open equally at each end (Fig. 9.4E). Larvae are mainly predacious, and feeding behaviour in some suggests that prey are detected from vibrations on outlying silken strands of the retreat, as by some spiders. The larvae ventilate the body surface by abdominal undulation, using essentially the same means to create respiratory currents w i t h i n their fixed tubes as do larvae o f Integripalpia i n portable tubes. This analogy is structural as w e l l ; case-making larvae of the Integripalpia have a lateral line of bifid filaments, but a number o f polycentropodid larvae are provided w i t h lateral setae, and probably both are an asset in pumping water through the tube. Perhaps this explains why larvae of some genera in the Polycentropodidae occur regularly i n lakes and ponds and, w i t h the 159

9 F a m i l y Polycentropodidae exception o f a few genera such as the psychomyiid genus Tinodes,

are the only ones

among North American Annulipalpia that can exploit lentic habitats in the absence o f water circulation induced by wave action. L i m i t s applied to the genus Polycentropus

i n North America are somewhat

than elsewhere, for together w i t h Polycentropus

species i n groups recognized by European workers as the genera Holocentropus

trocnemia.

broader

sens, str., there are also on this continent and Plec-

Tentative diagnostic characters for distinguishing N o r t h American larvae o f

Holocentropus,

Plectrocnemia,

and Polycentropus

sens. str. were provided by Hudson et

al. (1981); however, in view o f the large number o f Polycentropus

sens. lat. larvae still

unassociated, application o f these generic names to larvae on this continent is, at the very least, premature. Moreover, the names Holocentropus

and Plectrocnemia

are based prima-

rily on venational characters of species in the depauperate European fauna, and on a global scale may represent unnatural assemblages o f species (Armitage and H a m i l t o n 1990). None the less, structural and behavioural variation in larvae o f Polycentropus

sens. lat.

might, when more fully investigated, reveal some taxonomic congruence (see under Poly-

centropus).

Some of the subfamilies previously recognized in the Polycentropodidae have been elevated to family level, i.e. Dipseudopsidae and Hyalopsychidae; only the Polycentropodinae,

and the Pseudoneureclipsinae which are not represented in continental

North

America, remain. Taxonomic reviews o f North American genera in the Polycentropodidae based on the adult stage were provided by N i m m o (1986) and Armitage and H a m i l t o n (1990) K e y to G e n e r a * 1

Anal claw w i t h several conspicuous pointed teeth arising from ventral, concave 2

margin (Figs. 9.4A, 9.6A) A n a l claw lacking conspicuous pointed teeth on ventral concave margin

3

(Fig. 9.5D), or w i t h row o f many tiny spines (Fig. 9.3A) 2

(1) Teeth on anal claw much shorter than claw, dorsal accessory hook present (Fig. 9.4A); pronotum w i t h short, stout seta arising near each ventrolateral margin (Fig. 9.4c). Widespread over much o f continent, but not i n the southwest 9.4

Nyctiophylax

Teeth on anal claw almost as long as claw, dorsal accessory hook absent (Fig. 9 . 6 A ) ; pronotum lacking short seta near each ventrolateral margin. Southwestern 3

9.6

Polyplectropus

(1) Basal segment o f anal proleg approximately same length as distal segment and largely without setae, concave margin o f anal claw w i t h row o f tiny spines (Fig. 9.3A, C). Widespread in eastern and central areas

*See qualifications under Use of Keys, p. 7. 160

9.3 Neureclipsis

9 Family Polycentropodidae Basal segment o f anal proleg distinctly longer than distal segment and bearing many setae, concave margin o f anal claw lacking tiny spines (Fig. 9.2c) 4

4

(3) Dorsal plate between claw and lateral sclerite o f anal proleg w i t h t w o dark bands separated mesally (Fig. 9.2D); meso- and metanotal sal setae approximately same length as longest sal setae (Fig. 9.2B). Eastern and central

9.2 Cyrnellus Dorsal plate between claw and lateral sclerite o f anal proleg w i t h two dark bands fused mesally (Fig. 9.5E); metanotal and usually mesonotal sal setae not more than one-third as long as longest sal setae (Fig. 9.5B).

5

5

(4) Tarsus of fore leg elongate, about two-thirds as long as fore tibia, and anal claw curved approximately to 9 0 ° (Fig. 9.1A). Mature larvae not more than 8 m m in 1

length. South and east o f a line roughly from Arizona to Michigan, Ontario, and Maine.

9.1 C e r n o t i n a

1

Tarsus o f fore leg short, about one-half as long as fore tibia (Fig. 9.5A), or tarsus of fore leg elongate, approximately equal i n length to fore tibia or slightly longer, or anal claw not curved as much as 9 0 ° . Mature larvae 10 m m and longer. Widespread

9.5 Polycentropus

1

1 Distinction between Polycentropus and Cernotina is uncertain, primarily because so few of the North American species in these genera are known in the larval stage. But even among Polycentropus species that are known as larvae, consistent diagnostic characters have proven to be elusive (e.g. Morse and Holzenthal 1984). Thus, the fore tarsi in some species (e.g. P. crassicornis Walker) are elongate and about the same length as the fore tibiae (Fig. 9.5F), requiring that the diagnosis for Polycentropus larvae include both long and short fore tarsi. A distal cluster of three long setae on the tibia in some Polycentropus species seems to be diagnostic, and may be correlated with short tarsi (Fig. 9.5A). Curvature of the anal claw is distinct at the two extremes of 90° or only slightly curved, but difficult to interpret as the curvature approaches 90°. Distinction between one and several accessory hooks on the anal claw is difficult under normal binocular magnification; moreover, some Polycentropus larvae have no accessory hooks, making diagnosis of the two genera on that character uncertain. Therefore, in practice, Polycentropus larvae with short fore tarsi are distinguished from Cernotina readily enough. For diagnosis of Polycentropus larvae that have elongate fore tarsi, curvature of the anal claw to clearly less than 90° will resolve more of the species of Polycentropus, but others still prove difficult to place to genus. All of this is based on the assumption that other Cernotina species have the elongate fore tarsi of C. spicata, which is yet to be demonstrated. Further resolution can be made on the basis of size because mature larvae of Polycentropus are much larger than Cernotina. Finally, a geographic criterion should be applied to all larvae identified as Cernotina, based on present evidence that records for Cernotina adults lie south of a line extending from Arizona through Michigan to Ontario and Maine. Larvae found north of the line are likely to be Polycentropus; from south of the line, either genus could be expected, although Polycentropus would occur more frequently. There appears also to be a behavioural difference in the retreat constructed by larvae in the two genera (see under generic outlines). 161

9.1

Genus C e r n o t i n a

DISTRIBUTION AND SPECIES

This is a New World genus, widely represented from

Mexico and islands o f the Caribbean to Argentina, and extended north to Arizona, M i c h i gan, Ohio, Ontario, and Maine. Seven species are recognized i n N o r t h America north o f Mexico. Larvae have been identified for one species, C. spicata Ross, k n o w n from Virginia to

Georgia (Hudson et al. 1981). Diagnostic characters for this species were used for Cernotina in a key to North American genera by Morse and Holzenthal (1984). MORPHOLOGY

Larvae o f Cernotina

and Polycentropus

sens. lat. are difficult to distin-

guish unequivocally; but based on the few species i n both genera for w h i c h the larval stage is known, Cernotina

can be distinguished, but only in part, by longer and narrower

prothoracic tarsi and tibiae ( A ) , and by a right-angled claw o f the anal proleg that bears a single accessory tooth ( A ) (see footnote i n Key to Genera). The head o f C. spicata ( B ) is light brownish yellow, w i t h darker spots marking muscle attachments; mandibles are asymmetrical (Hudson et al. 1981, f i g . 2), the left mandible has three subapical teeth both dorsally and ventrally, the right mandible has t w o dorsal and three ventral subapical teeth, and the dorsal margin overhangs the ventral margin. Metanotal sal setae are no more than one-third as long as the longest sal setae ( B ) . Tarsi of the fore legs are nearly as long as the tibiae, and approximately twice as l o n g as broad ( A ) . The distal end of the tarsus on all legs bears several broad, fringed setae ( C - E ) . On the anal proleg the basal segment is much longer than the distal segment and bears many setae ( A ) , and the two dark bands o f the dorsal plate are partly fused ( F ) ; the claw bears one dorsal accessory tooth but lacks teeth on the concave ventral edge ( A ) . Length o f larva up to 8 mm. Larvae o f C. spicata

RETREAT

cover small depressions on the surface o f rocks w i t h a

silken roof bearing a flared opening at each end (Hudson et al. 1981), much as in Nyctio-

phylax (Fig. 9.4E) and Cyrnellus

Adults o f Cernotina

BIOLOGY

(Fig. 9.2E). species have been collected i n habitats ranging from

fast-flowing streams to impoundments o f large rivers. Larvae o f C. spicata were found in small rocky creeks and large rivers as well as impoundments (Hudson et al. 1981), and were most numerous at depths o f 0.5 to 4 m, occasionally to 16 m . Larvae are predacious; gut contents (n=5) included chironomid larvae and small crustaceans (Hudson et al. 1981). REMARKS

Taxonomy and distribution o f adults o f Cernotina

were summarized

by

Armitage and Hamilton (1990), and by N i m m o (1986). Specimens studied here were provided by J.R. Voshell.

Cernotina

spicata (Virginia, Louisa Co., 5 A u g . 1975, ROM)

A , larva, lateral x 2 2 , detail of anal proleg; B , head and thorax, dorsal; C, D , E, tarsi and claws of fore, middle, and hind legs respectively, mesal; F, dorsal plate o f anal proleg, dorsal 162

Polycentropodidae: Cernotina

9.1

163

9.2 Genus C y r n e l l u s D I S T R I B U T I O N AND S P E C I E S Cyrnellus is a New World genus, with only a single Nearctic species C. frai emus (Banks) (syn. C. marginalis (Banks)), which is recorded from Minnesota to Texas and eastward (Ross 1944; Flint 1964a); the species is evidently much more common i n southeastern and mid-western areas than in northeastern. The same species has also been recorded from the Amazon River and Argentina in South America (Ross 1944; Flint 1964a), along w i t h several others of the genus. Identity o f Cyrnellus larvae was established by Ross (1959), and the larva of nus described by Flint (1964a).

C.frater-

M O R P H O L O G Y Distinction between larvae o f Cyrnellus and Polycentropus has always been difficult, and all the more so since our material o f Polycentropus indicates that muscle scars o f the head can be lighter than the base colour as well as darker as stipulated in other diagnoses (e.g. Flint 1964a). But up to now i n all Polycentropus larvae that we have found, the t w o dark, sclerotized bands of the dorsal plate between the claw and lateral sclerite of the anal proleg are partly fused to form an X-shaped sclerite. I n C. fraternus these two dark, sclerotized bands do not touch at any point ( D ) ; the anal claw lacks teeth on the concave, ventral surface (C), as i t does i n Polycentropus. Length of larva up to 9 mm. R E T R E A T Larval retreats of specimens we collected in Tennessee (E) were somewhat similar to those of Nyctiophylax. A depression i n a rock is covered by a flattened silk roof, roughly circular i n outline; a round opening through the silk at each end provides egress for the foraging larva. The larval chamber has a silk floor and the larva can reverse its position within. Viewed from above, the silk roof of the retreat has a diameter of approximately 20 m m but is obscured by fine organic sediment. B I O L O G Y A l t h o u g h C. fraternus shows a marked preference for large rivers, it occurs in a wide range of waters from smaller streams to lakes and reservoirs (Ross 1944; Flint 1964a). We collected the larval series illustrated on rocks in water approximately 60 cm deep along the edge o f an impoundment ( O l d Hickory Reservoir, Cumberland R., Tenn.), and larvae were also collected at that locality i n the river below the dam at a depth of 15 ft (4.6 m) (Flint 1964a). Larval guts (3) that we examined all contained fine organic particles, w i t h arthropod remains i n one. REMARKS

Taxonomy and distribution of C. fraternus

were summarized by Armitage

and Hamilton (1990).

Cyrnellus fraternus (Tennessee, Davidson Co., 13 M a y 1970, R O M 700335) A, larva, lateral x20, tibiae and tarsi enlarged; B, head and thorax, dorsal; C, anal proleg, lateral; D , dorsal plate o f anal proleg, dorsal; E, diagram o f retreat on rock, based on field notes, approx. x l . 4 164

Polycentropodidae: Cyrnellus 9.2

165

9.3 Genus N e u r e c l i p s i s D I S T R I B U T I O N AND S P E C I E S

Six species of Neureclipsis

are known i n North Amer-

ica, and all occur in the eastern half o f the continent; one of them, N. bimaculata

( L . ) , is

Holarctic and extends westward to British Columbia and Alaska, through northern Asia and Europe. Larvae have been described for N crepuscularis

bimaculata

(Walker) by Ross (1944) and for N.

( L . ) by Lepneva (1964). We have associated larval material for both species

and also for N. valida (Walker).

M O R P H O L O G Y Larvae o f Neureclipsis are distinguished by a shortened basal segment of the anal proleg that is approximately the same length as the distal segment (A, C) and lacks setae, although a few setae may arise at the junction o f the basal and distal segments. The concave, ventral edge o f the anal claw bears a row of tiny spines (A). Larvae o f N bimaculata have a pair o f short stout setae on the venter o f segment I X (c). Length o f larva up to 21 m m . R E T R E A T The larval retreat in this genus is a distinctive trumpet-shaped net of silk ( D ) that tapers to a slender tube where the larva is concealed. Guy lines of silk support the large opening exposed to the current, and prey organisms are filtered from the water. Netspinning behaviour of N. bimaculata was studied i n Germany by Brickenstein (1955), and in Sweden by Petersen et al. (1984). Excluding the recurved posterior end, nets range up to at least 12 cm i n length or perhaps longer, and 3 to 4 cm i n diameter at the anterior end. B I O L O G Y Filter feeding o f Neureclipsis larvae obliges them to live i n running waters, but in slow currents since the nets are large and vulnerable to strong currents. On rooted aquatic plants and submerged tree branches, the nets are often abundant; staged one below the other, they exploit the full potential o f the water column. Larvae feed mainly on zooplankton and insects (Petersen et al. 1984). The life cycle o f N. bimaculata was interpreted as bivoltine in Alberta by Richardson and Clifford (1983); larvae do not construct filter nets during the colder months, but remain i n tubular silken retreats on substrates such as aquatic plants. Distribution of larval filter nets appeared to be correlated w i t h the occurrence of small limnetic zooplankton, factors which contribute to major concentrations of larvae below the effluents of lakes (Richardson 1984). The biology of other species of Neureclipsis is similar (Richardson and Clifford 1983; Cudney and Wallace 1980). REMARKS

Taxonomy and distribution o f adults were summarized by Armitage and

Hamilton (1990), and by N i m m o (1986) for species in Canada.

Neureclipsis bimaculata (South Dakota, Yankton Co., 1968, R O M ) A, larva, lateral x9, propleuron, fore tarsus, and anal claw enlarged; B, head, pro- and mesonotum, dorsal; C, segment I X and anal prolegs, ventral; D , larval capture net and retreat (after Brickenstein 1955), arrow indicating direction of current 166

Polycentropodidae: Neureclipsis 9.3

167

9.4 G e n u s N y c t i o p h y l a x DISTRIBUTION A N D S P E C I E S The genus Nyctiophylax (sens, lat.) has been recorded from most faunal regions (Fischer 1960-73). Ten species have been identified in North America; some are confined to the southeastern United States, others are widespread through the eastern half o f the continent extending westward to British Columbia and Oregon. Taxonomy of the North American species was revised by Morse (1972). Generic characters were summarized by Flint (1964a), and larvae have been described for three North American species: N. celta Denning by Ross (1944, as Psychomyiid Genus B) and by Flint (1964a, as N. vestitus (Hagen)); N. moestus Banks by Noyes (1914, as Cyrnus pallidusl), by Ross (1944, 1959, as Psychomyiid Genus A ) , and by Flint (1964a, as Nyctiophylax sp. A ) ; N. nephophilus Flint by Flint (1964a). We have associated larvae for several species, including N. affinis (Banks). M O R P H O L O G Y Larvae o f this genus are distinguished by short teeth on the ventral, concave surface of the anal claw ( A ) , and by a short, stout lateral seta on each side o f the pronotum ( C ) . Small spines on venter I X are arranged in a T-shaped field, and spines also occur on the venter o f the basal segment o f the anal prolegs ( D ) . The anal claw bears an accessory tooth. Length o f larva up to 10 m m . R E T R E A T Larval retreats o f Nyctiophylax species (E) consist of a silken roof over a depression in a piece o f wood or a rock, enclosing a flattened chamber open at each end; the silken floor is extended beyond the roof at each end as a threshold o f threads. A covering o f silt and diatoms makes the shelter difficult to detect. According to Noyes (1914) each opening can be closed by a flap-like extension o f the silken roof, and a loose network of threads floats up from the threshold; the larva darts out from the retreat to capture small creatures that cause the threshold threads to vibrate. Length o f larval retreat up to at least 15 m m . B I O L O G Y Nyctiophylax larvae live i n lakes and streams, but i n running waters they are generally to be found in pools and sections w i t h reduced current. Larvae are almost entirely carnivorous (Coffman et al. 1971). R E M A R K S Taxonomy and distribution for adults o f North American species o f Nyctiophylax were summarized by Armitage and Hamilton (1990) and N i m m o (1986). Nyctiophylax and Paranyctiophylax were defined as sister groups and proposed as genera by Neboiss (1993); the North American species were assigned tentatively to Paranyctiophylax. I prefer to retain Nyctiophylax for the North American species until diagnostic characters are provided for larvae o f the t w o taxa (see comment under Lepidostomatidae, pp. 241-2).

Nyctiophylax sp. (Arkansas, Washington Co., 5 M a y 1970, ROM 700306) A , larva, lateral x l 5 , anal claw enlarged; B , head and thorax, dorsal; C , right margin o f pronotum and pleuron, dorsal; D , segment i x and bases o f anal prolegs, ventral N. affinis (Ontario, Muskoka Dist., M a y 1975): E, larval retreat on wood substrate 168

Polycentropodidae: Nyctiophylax 9.4

169

9.5 Genus P o l y c e n t r o p u s D I S T R I B U T I O N AND S P E C I E S Polycentropus sens. lat. occur i n most faunal regions. Approximately 45 species are now known in North America north of Mexico, and the genus is represented over much of the continent. Larval stages have been described for six species (Ross 1944); we have associated larvae for an additional six species. M O R P H O L O G Y Muscle scars of the head are darker than the base colour in some species (B), but lighter in others. The single seta in the meso- and metanotal sal position is consistently shorter than the longest sal seta (B). I n some species, e.g. P. cinereus Hagen, the tarsus is short and about half as long as the tibia (A); in others, e.g. P. crassicornis Walker, the tarsus and tibia are approximately the same length (F). Three long setae are clustered together at the distal end o f the tibia in some species (A), mainly in those larvae w i t h short tarsi. Abdominal segments bear a broad band o f setae along each side (A). The claw of the anal proleg is variably curved up to 9 0 ° , and may or may not bear a slender dorsal accessory hook (D). The two dark sclerotized bands of the dorsal plate of the anal proleg are partly fused (E). Most of these characters occur also in larvae o f Cernotina (9.1), and separation o f the two genera is uncertain (see footnote i n Key to Genera). Length of larva up to 25 m m . R E T R E A T For North American larvae assigned to Polycentropus sens, lat., we have found two types of retreats. One is a loosely constructed silken tube, where larvae rest, and dart out to seize small prey that move across a maze of silken threads; in a similar net (G) illustrated by Noyes (1914), the tube was 21 m m long. The other type is a bag-like structure expanded by the current, similar to a small Neureclipsis net and illustrated for P. flavomaculatus (Pictet) by Wesenburg-Lund (1911). Net-spinning behaviour i n European species of the Polycentropus complex was summarized by Edington (1964). B I O L O G Y North American larvae o f Polycentropus live in most types of freshwater habitats. This is the only genus of retreat-making Trichoptera k n o w n in temporary pools (Wiggins 1973a); I have taken them also from lake sediments at depths of 5 m i n association w i t h Chironomus larvae. The larvae are primarily predacious (Coffman et al. 1971; Winterbourn 1971a). REMARKS

Taxonomy and distribution o f adults were summarized by Armitage and

Hamilton (1990), and by N i m m o (1986) for species in Canada.

Polycentropus sp. (Ontario, Muskoka Dist., 16 Sept. 1967, ROM) A, larva, lateral x l 2 , fore tibia and tarsus enlarged; B, head, pro- and mesonotum, dorsal; C, maxillae and labium, ventral, labial palp enlarged; D, anal proleg, lateral; E, dorsal plate of anal proleg, dorsal P. crassicornis (Ontario, Durham Co., June 1972, ROM): F, tibia and tarsus Polycentropus sp.: G, larval retreat, approx. x l . 6 (after Noyes 1914) 170

Polycentropodidae: Polycentropus 9.5

171

9.6 G e n u s P o l y p l e c t r o p u s D I S T R I B U T I O N AND S P E C I E S Species assigned to Polyplectropus occur in North and South America, Africa, and Asia, although some of the O l d World species may not be congeneric (Flint 1968a). Several species occur in M e x i c o and southward, but only P chariest (Ross) and P. proditus (Edwards) from Texas are yet known north of Mexico. The larva described by Flint (1964a) as Genus C is believed to belong to

Polyplectro-

pus (Flint 1968a), and probably to P. chariest since i t was collected at the type locality of that species i n Texas.

M O R P H O L O G Y Larvae are clearly distinguished from all other North American polycentropodids by the long teeth on the ventral concave margin of the anal claw (A); the anal claw lacks an accessory tooth. A central dark patch on the dorsum o f the head, broken by pale muscle scars, is also characteristic (B); the basal segment o f the anal proleg is somewhat longer than the distal and bears a few setae. Length of larva up to 8 m m . RETREAT

The retreat o f Polyplectropus

tiophylax (Flint 1964a). BIOLOGY REMARKS

larvae is reported to be similar to that o f Nyc-

Larvae live on rocks in small, cool streams (Flint 1968a). The larva illustrated, collected in San Felipe Spring near Del Rio, Texas,

was made available by O.S. Flint.

Polyplectropus

sp. (prob. chariest (Texas, Val Verde Co., 21 Sept. 1960, U S N M )

A, larva, lateral x26, anal claw enlarged; B, head, pro- and mesonotum, dorsal; C, head, ventral 172

Polycentropodidae: Polyplectropus 9.6

173

10 Family Psychomyiidae

The Psychomyiidae are a small family widely distributed over much of the world. Four genera are recognized in the Nearctic region, w i t h a total of about 17 species i n Canada and the United States; representatives occur in most parts of the continent, at least one ranging as far north as the tree line. The larvae differ from those of the Polycentropodidae in several features. One character diagnostic for the Psychomyiidae is the broad, hatchet-shaped trochantin of the protho¬ rax, which is separated from the propleuron by a well-marked suture (Fig. 10.4c). The labium is extended well beyond the anterior margin of the head (Fig. 10.3c), probably to facilitate application o f silk to the interior of the dwelling tube; labial palpi are absent. The maxillary lobe is broad and flattened, the submental sclerites usually paired and separate (Fig. 10.3c). The pronotum alone is sclerotized, and the fore legs stouter than those of the other segments; tarsal claws are short, bearing a stout basal process w i t h a long seta. The abdomen lacks the lateral setae of the Polycentropodidae, and anal papillae are usually present. The basal segment of the anal proleg is much shorter than the distal segment that bears the lateral sclerite, and the anal claw is w e l l developed. Psychomyiid larvae construct tubes of silk covered w i t h sand and debris on rock and wood substrates where they feed on periphyton. According to Nielsen (1959), the tube is moved slowly across the substrate as the larva breaks down one end and adds on to the other. I n this way new grazing areas can be reached as those adjacent to the ends of the tube are depleted. For the most part, larvae live i n cool, running water, but some Tinodes live in isolated stream pools in western North America and along lake margins i n Europe. This evidence of independence from stream current i n Tinodes is noteworthy because the larvae lack lateral abdominal setae, which might be an asset for larvae of Polycentropodidae i n generating their o w n respiratory current. Available information indicates that psychomyiid larvae feed mainly on detritus and associated microflora (Lepneva 1964) and algae. There are t w o subfamilies in the Psychomyiidae, both represented i n North America. The Psychomyiinae include hype, Psychomyia, and Tinodes, and are widely distributed over the globe. The Paduniellinae are represented in North America only by Paduniella, but otherwise the subfamily is widespread i n Asia and Africa. 174

10 F a m i l y P s y c h o m y i i d a e K e y to G e n e r a * 1

2

Anal claw w i t h well-developed teeth arising from ventral, concave margin (Fig. 1 0 . 3 A )

2

A n a l claw without teeth on ventral, concave margin (Fig. 10.4A)

3

(1) Ventral surface of labium w i t h paired submental sclerites prominent and much longer than wide (Fig. 10.3c). Widespread

10.3

Psychomyia

Ventral surface of labium w i t h paired submental sclerites smaller and wider than long (Fig. 10.2c). Arkansas, Missouri 3

10.2 PadunieUa

(1) Mandibles w i t h prominent dorsolateral bump anterad o f base, often larger on one mandible, dorsolateral condyle may or may not be prominent, pair of lateral setae arising near middle o f each mandible (Fig. 10.4D); submental sclerites usually rather large, approximately half as long as wide. Western 10.4

Tinodes

Mandibles lacking prominent dorsolateral bump, but small dorsal condyle located close to base, pair o f lateral setae arising approximately one-third o f distance from base o f each mandible (Fig. 10. l c ) ; submental sclerites smaller, approximately one-third as long as wide (Fig. 1 0 . I D ) . Eastern

10.1 L y p e

*See qualifications under Use of Keys, p. 7. 175

10.1 Genus L y p e D I S T R I B U T I O N AND S P E C I E S Several species of this genus are known in Europe, but only a single species, L diver sa (Banks), occurs i n North America; it is confined to the eastern half of the continent, extending as far north as Wisconsin, Ontario, Q u é b e c , and Maine. Diagnostic characters at the generic level were given by Ross (1959) and Flint (1964a); the larva of L diversa was described i n detail by Flint (1959). M O R P H O L O G Y The larva of Lype diversa is similar to that of the western genus Tinodes, and seems best distinguished by the structure of the mouthparts. In Lype there is no prominent dorsolateral bump on the mandibles as there is in Tinodes, although a small dorsal condyle is located close to the mandibular base (c); the paired lateral setae on each mandible are situated basad of the mid-lateral point (c). There are two setal brushes on the inner edge of the left mandible, and the mandibles are approximately as long as they are wide. The submental sclerites are smaller than i n Tinodes, and approximately one-third as long as wide (D). Length of larva up to 8.5 m m . R E T R E A T Larval retreats of L diversa (E) are exceedingly well camouflaged. A slightly arched roof of silk and small pieces of detritus cover a depression in a piece of submerged wood, forming a chamber in which the larva is concealed. The retreat is open at each end. Length of retreat illustrated approximately 8 m m . B I O L O G Y Larvae o f L diversa live in small, cool streams, where their retreats are usually constructed on submerged logs and branches. The retreat illustrated was found on small pieces o f wood incorporated into the case of a l i v i n g larva o f Limnephilus. Larvae are believed to graze on fine organic particles, and perhaps algae as well. R E M A R K S Taxonomy of adults and distribution o f L. diversa were summarized by N i m m o (1986) and Armitage and Hamilton (1990). A European species, Lype phaeopa (Stephens), shows little change in male genitalic morphology from specimens preserved i n Baltic amber from the upper Eocene epoch, some 50 m i l l i o n years in age (Ross 1958).

Lype diversa (South Carolina, Oconee Co., 17-18 M a y 1970, ROM 700347) A, larva, lateral x l 9 , trochantin enlarged; B, head, pro- and mesonotum, dorsal; C, mandibles, dorsal; D, head, ventral; E, retreat, dorsal approx. x l 2 176

Psychomyiidae: Lype 10.1

177

10.2 G e n u s P a d u n i e l l a DISTRIBUTION AND SPECIES

This genus is widely represented in Asia from India

and the Far East of Russia to the Philippines and Indonesia, and also in Africa and southern France. A single species, P nearctica

Flint, is k n o w n i n North America but to date

only i n Arkansas and Missouri (Flint 1967d; Mathis and Bowles 1994). Identity o f the larva o f P. nearctica

has been established i n the same Arkansas stream

on which the type locality is situated (Mathis and Bowles 1994). MORPHOLOGY

Although the larva o f Paduniella

ventral margin o f the anal claw ( F ) as in Psychomyia

nearctica

has prominent teeth on the

(Fig. 10.3), the submental sclerites

( C ) are not enlarged as i n that genus, but are small as they are i n Lype and Tinodes; and the

ventral apotome ( C ) is broad and triangular as in Lype and Tinodes,

equilateral triangle o f Psychomyia.

The mandibles o f P nearctica

rather than the tiny

( D , E ) are narrower than

in Lype and Tinodes, and the right mandible has a prominent mesal notch. The head of P.

nearctica

( B ) is longer than wide, rather than squarish as i n Psychomyia.

The prothoracic

episternum has dorsal emarginations ( A ) , lacking in the other genera. Membranous thoracic segments and the abdominal segments bear a prominent dark median dorsal band; anal papillae are evident ( F ) . Length o f larva up to 9 m m ; the larva illustrated is probably not a final instar. Larvae o f Paduniella

RETREAT

construct silken tubes w i t h sand and other materials

adhering to them; several tubes are fastened to a single rock as i n Psychomyia

(Fig.

10.3D). Tubes up to 22 m m i n length and 2-3 m m in width were recorded by Mathis and Bowles (1994). Populations o f P nearctica

BIOLOGY

are mainly confined to headwater streams o f the

Ozark Mountains, where larvae occur i n areas o f l o w velocity and large stable substrates (Mathis and Bowles 1994). Larval retreats were located in depressions on the upper surfaces o f rocks. Larvae fed mainly on diatoms, with a sizeable component of fine detritus in the summer. REMARKS

This single species is the sole North American representative o f the subfam-

ily Paduniellinae. Taxonomy o f Paduniella

adults i n North A m e r i c a was reviewed by

Armitage and H a m i l t o n (1990); morphology o f the female o f P. nearctica

was described

by Bowles and A l l e n (1988).

Paduniella

nearctica

(Arkansas, Washington Co., 10 July 1987, R O M )

A , larva, lateral x approx. 17, detail o f pleuron and trochantin; B , head, pro- and mesonotum, dorsal; C, maxillae, labium and ventral apotome, ventral; D , mandibles, dorsal; E, mandibles, ventral; F, segment I X and anal prolegs, dorsal 178

Psychomyiidae: Paduniella 10.2

179

10.3 Genus P s y c h o m y i a D I S T R I B U T I O N AND S P E C I E S Psychomyia are Holarctic and Oriental i n distribution. Three species are known i n North America: P. flavida Hagen throughout most of the continent to the edge of the tree line at Churchill, Manitoba (Lehmkuhl and Kerst 1979), and recorded also from Siberia (Schmid 1965); P. lumina (Ross) in the western United States; and P. nomada (Ross) i n the east. The larva of P. flavida was described by Ross (1944), and larvae of P. flavida and P. nomada by Flint (1964a). We have associated material for these species, and larvae o f a western species illustrated here from material we collected in Oregon, which is probably P. lumina.

M O R P H O L O G Y Psychomyiid larvae i n N o r t h America with teeth on the ventral, concave margin o f the anal claw (A) belong to Psychomyia or Paduniella. I n Psychomyia the submental sclerites are very large, each one much longer than wide, and the ventral apotome is reduced to a small equilateral triangle (C). I n the series illustrated, probably P. lumina, the anterior margin of the frontoclypeal apotome (B) lacks the median notch characteristic of the other t w o species; larvae o f all three Nearctic species can probably be separated on the basis of different development o f this notch (cf. Flint 1964a, fig. 5). Length o f larva up to 9 m m . R E T R E A T The larvae illustrated construct meandering tubes o f silk several centimetres long covered with sand grains on rocks ( D ) . I n eastern species these tubes are little more than 1 c m i n length. B I O L O G Y I n North America, Psychomyia larvae are usually found i n rivers and streams, although European species are also reported from the littoral zone of lakes (Lepneva 1964). Gut contents o f P flavida i n a Pennsylvania woodland stream were found to be largely algae w i t h smaller proportions o f detritus and animals (Coffman et al. 1971). Guts (3) from the larval series illustrated all contained some vascular plant tissue, as well as fine organic particles. P. flavida is probably facultatively parthenogenetic (Corbet 1966); females are often abundant i n light traps, and males, though infrequently collected, are sometimes found i n equal proportions. R E M A R K S Taxonomy and distribution o f adults were summarized by Armitage and Hamilton (1990).

Psychomyia (prob. lumina) (Oregon, Benton Co., 7 A p r i l 1964, ROM) A, larva, lateral x l 8 , tarsi and anal claw enlarged; B, head, pro- and mesonotum, dorsal; C, ventral apotome and mouthparts, ventral; D , rock w i t h sand-covered tubes, approx. x0.25, section o f tube enlarged 180

Psychomyiidae: Psychomyia 10.3

181

10.4

Genus

Tinodes

DISTRIBUTION

AND SPECIES

Species o f Tinodes occur in most faunal regions. I n

North America north o f M e x i c o twelve species are recognized, all in western montane areas. Generic characters for Tinodes larvae were given by Ross (1959) and Flint (1964a). I n the ROM collection we have larvae for three species and series o f larvae from several other localities. M O R P H O L O G Y I n larvae o f Tinodes each mandible usually has a prominent dorsal bump near the lateral margin distad o f the base (D, E), but the bump is often larger on one mandible. The dorsolateral mandibular condyle basad o f the bump may or may not be prominent. The pair o f lateral setae on each mandible is situated at about its mid-point; the left mandible bears only a single setal brush on the inner edge, and both mandibles are somewhat longer than wide. The submental sclerites are usually larger than in Lype, approximately half as long as wide. Some European species have small teeth on the concave edge o f the anal claw, but North American larvae now k n o w n lack these teeth ( A ) . Length o f larva up to 15 m m . R E T R E A T Tinodes larvae construct flattened, silken tubes covered w i t h sand, usually on rock surfaces ( F ) ; the tube has a thin silken floor. Tubes are variable i n length, but often reach several centimetres. B I O L O G Y Our larval collections were made in rather w a r m streams o f desert country. Those assumed to be T powelli Denning came from isolated pools o f a desert stream o f widely fluctuating flow in California (Deep Creek, R L . B o y d Desert Research Center, Riverside Co., provided by S.I. Frommer); adults were collected in June. Water temperatures in a series o f these pools in Deep Creek ranged from 18 to 2 7 . 5 ° C (Frommer and Sublette 1971). Larvae assumed to be T provo Ross came from a spring-fed stream in Idaho (Deep Creek, Oneida Co., provided by R . L . N e w e l l ) w i t h a constant temperature o f approximately 18°C; adults were collected in January, but some other aquatic insects, normally bivoltine, had multivoltine life cycles at this site (R.L. Newell, pers. comm.). Larvae feed mainly on detritus and algae. R E M A R K S Taxonomy o f adults was reviewed by Denning (1956), and more recently by Armitage and H a m i l t o n (1990).

Tinodes (prob. powelli) (California, Riverside Co., 13 June 1969, ROM) A, larva, lateral x l 2 , claws o f tarsus and anal proleg enlarged; B , head, pro- and mesonotum, dorsal; C, pleuron and trochantin w i t h fore coxa, lateral; D, mandibles, dorsal; E, right mandible, lateral; F, section o f retreat, dorsal approx. x4 182

Psychomyiidae: Tinodes

10.4

183

This page intentionally left blank

11 Family Xiphocentronidae

From inception as a family o f one genus (Ross 1949), the Xiphocentronidae have become through recent revision a family o f seven genera w i t h about one hundred species (Schmid 1982). As defined by Schmid, the family is widely distributed through Asia, Africa, South America, Central America and the Antilles, and North America. The genus Xiphocentron is represented in southwestern North America. Adults o f a second genus o f this family, Cnodocentron, have been recorded from Arizona ( M o u 1 ton et al. 1994); larvae are unknown in Cnodocentron. Larval diagnosis for the entire family cannot be given because four o f the seven genera assigned to the Xiphocentronidae (Schmid 1982) are unknown as larvae. Larvae are known for Xiphocentron from the New World. Larvae o f Abaria from Africa (Scott 1985) are morphologically congruent w i t h Xiphocentron. The larva o f Melanotrichia s erica from Asia is also congruent w i t h Xiphocentron (Barnard and Dudgeon 1984). However, in his revision of the Xiphocentronidae based on adult stages, Schmid (1982) found that few o f the morphological characters o f the type genus Xiphocentron were diagnostic for the family as newly defined. U n t i l larvae o f these remaining genera become k n o w n , and their morphology studied, I treat the larval diagnosis for Xiphocentronidae here in terms o f the type genus Xiphocentron.

185

11.1 Genus X i p h o c e n t r o n D I S T R I B U T I O N AND SPECIES

Species of Xiphocentron

occur in Mexico, the Antilles,

and Central and South America (Schmid 1982). One species, X. messapus Schmid, occurs in southern Texas; the larva and pupa were described by Edwards (1961, as X.

mexico

Ross). M O R P H O L O G Y Larvae o f Xiphocentron resemble those of the Psychomyiidae i n general structure ( A ) , but the prothoracic trochantin is not broad and hatchet-shaped as in that family. The partly membranous trochantin of Xiphocentron is much smaller, although it is separated from the propleuron by a well-marked suture (E). The larva of Xiphocentron is further distinguished by a lobate process extending anterodorsad from the mesopleuron (A, B ) ; the base o f this process arises from within a linear invaginated pocket (D). The tibiae and tarsi of all legs are fused together as a single segment (A, D); the posterolateral corners of the pronotum are extended ventrally as a thin sclerotized band. The ventral apotome o f the head is broadly triangular as i n psychomyiids such as Tinodes, but submental sclerites are lacking (C). The labium is elongate and labial palpi are lacking (C), as i n Psychomyiidae, and the maxillary lobes are prominent. A n a l papillae are present. Length of larva up to 8 m m . R E T R E A T According to Edwards (1961), larvae of Xiphocentron messapus build tubes of fine sand grains on rocks below the water surface, and the tubes frequently extend several centimetres above the surface on wet substrates; tubes up to 5 cm long and 2.5 m m wide were recorded. I have collected Xiphocentron larvae in sand tubes up to 10 cm in length from rocks in cloud-forest streams in Costa Rica; the tubes are similar to those constructed by larvae of the psychomyiid genus Tinodes. A t the ends of tubes on the undersides of logs overhanging streams, larvae of a Colombian species constructed pendant ovoid vesicles of silk i n which they pupated above the water (Sturm 1960). B I O L O G Y Larvae of X. messapus were found in the outflow of a small spring (Edwards 1961), and the Antilles species live in small streams (Flint 1964b). The lobate process o f the mesopleuron is unusual, i f not unique, in trichopteran larvae; its membranous surface and oddly invaginated base suggest some sensory function. Since the mandibular structure and tube-making behaviour of Xiphocentron larvae are similar to the Psychomyiidae, it is reasonable to infer that these larvae also graze algae and organic particles. R E M A R K S Taxonomy based on adult morphology was summarized by Armitage and Hamilton (1990). Larvae illustrated were provided by O.S. Flint.

Xiphocentron messapus (Texas, Hays Co., 1 July 1960, USNM) A , larva, lateral x24, anal claw enlarged; B , head, pro- and mesonotum, dorsal; C, head, ventral; D, prothorax and mesopleuron, right side, lateral; E, fore trochantin, right side, ventral 186

Xiphocentronidae: Xiphocentron

11.1

187

This page intentionally left blank

Suborder INTEGRIPALPIA: Portable-case makers Larvae are mostly eruciform with an hypognathous head; the anal prolegs are short and the anal claws are small. Portable cases constructed i n all instars enable larvae to move to new food resources. Pupation i n most families occurs within the larval case, after the case has been fixed to a substrate and the ends closed against predators. Small openings i n the ends o f the case permit water to flow directly over the developing pupa for respiration; a flow o f water through the case is regulated by the ventilating undulations of the insect's abdomen. The w o r l d fauna of the Integripalpia consists o f approximately 30 families, and several are endemic to the northern or southern hemispheres. I n North America 15 families are represented. 12 13 14 15 16

Apataniidae Beraeidae Brachycentridae Calamoceratidae Goeridae

17 18 19 20 21

Helicopsychidae Lepidostomatidae Leptoceridae Limnephilidae Molannidae

22 23 24 25 26

Odontoceridae Phryganeidae Rossianidae Sericostomatidae Uenoidae

The superfamilies Phryganeoidea (p. 10) and Limnephiloidea (p. 11) were defined by Gall and Wiggins (in press); evidence for the Leptoceroidea (p. 13) and Sericostomatoidea (p. 13) was reviewed by Frania and Wiggins (inpress).

189

12 Family Apataniidae

The family Apataniidae (Gall and Wiggins, i n press) brings together the subfamily Apataniinae, formerly o f the Limnephilidae, w i t h four o f the genera placed previously as L i m nephilidae incertae sedis (Wiggins 1973c). Members of the Apataniidae are widespread i n the Holarctic and Oriental faunal regions; five genera are represented i n North America. The Apataniidae represent the coincidence o f several uncommon trends in larval characters: wedge-like shape of the ventral apotome; mandibles with scraper blades for grazing; pronotum inflated; and metanotal sal with many setae on the integument. N o t all o f these characters occur i n each genus, and the genera differ i n some other characters. I n all genera, the antennae are located between the eye and the anterior margin of the head capsule. Metanotal sal sclerites are lacking in two genera. Abdominal gills are single or lacking. Larvae o f this family are primarily residents of cool running waters, but under conditions o f the far north or at high elevation, Apatania

larvae live i n cold lakes.

Moselyana

larvae appear to be confined to the organic muck o f spring seepage areas. A l l Nearctic species construct cases o f small rock fragments, although larvae of Manophylax

add bits

o f plant detritus, apparently as surface camouflage rather than as integral parts o f the case structure. K e y to G e n e r a * 1

Metanotal sal sclerites discrete, about the same size as the sal sclerites (Fig. 12.3B)

2

Metanotal sal sclerites lacking, but the setae present and continuous across the dorsum as a line (Fig. 12.2B) or a broad patch (Fig. 12.5B) 2

(1) Basal seta o f tarsal claws short, extending far short o f tip of claw (Fig. 12.4A);

*See qualifications under Use of Keys, p. 7. 190

4

12 Family Apataniidae mandibles with separate tooth-like points (Fig. 12.4D); many metanotal setae not on primary sclerites (Fig. 12.4B). Western 12.4 Moselyana Basal seta of tarsal claws long, extending to or almost to tip of claw (Fig. 12.1A); mandibles with apical edge entire and not subdivided into tooth-like points (Fig. 1 2 . I D ) ; most metanotal setae confined to primary sclerites (Fig. 12.3B)

3

3

( 2 ) Venter of abdominal segment I with an anteromedian sclerite (Fig. 12.3E), with or without a central unsclerotized area; head unmodified and uniformly convex (Fig. 12.3B). Eastern and western 12.3 Manophylax Venter of abdominal segment I lacking an anteromedian sclerite; dorsum of head flattened, frequently with prominent carina (Fig. 12.1A, B). Western 12.1 Allomyia

4

( 1 ) Metanotal sa\ setae arranged more or less linearly across mid-dorsal line, mesonotum with two large, undivided plates (Fig. 12.2B). Widespread 12.2 Apatania Metanotal sal setae abundant in broad patch across mid-dorsal line, mesonotum with each plate subdivided longitudinally into two sclerites (Fig. 12.5B). Western 12.5 Pedomoecus

191

12.1 Genus Allomyia D I S T R I B U T I O N AND S P E C I E S This genus, formerly I mania, comprises 12 species occurring in mountainous areas of western North America from Alaska to Colorado and Nevada; other species occur in eastern Russia and Japan. Larvae referred to L i m n e p h i l i d Genus A by Ross (1959) and Flint (1960) are Allomyia. We have identified larvae for four species (Wiggins 1973c) and collected series belonging to this genus from many western localities. The larva of a Siberian species, A. sajanensis Levanidova, has been described (Levanidova 1967). M O R P H O L O G Y The head in larvae o f Allomyia is flattened dorsally, the dorsum frequently concave and bounded by a sharp, semicircular carina (B); posterodorsal horns on the head (A, B) are known only i n A. scotti (Wiggins). The head and pronotum have a pebbled texture. Other characters o f the head include scraper mandibles w i t h apical edges entire and not subdivided into teeth (D), a T-shaped ventral apotome (F) i n which the lateral margins are straight rather than convex as in the other genera, and a labrum w i t h a membranous anterior margin ( E ) . The pronotum is strongly convex, the mesonotal plates are shorter than in most other genera, and most metanotal setae are confined to the primary sclerites; the basal seta o f the tarsal claws extends almost to the tip of the claw (A, B). Abdominal gills may be present but usually are lacking. Length of larva up to 11.5 m m . C A S E Larvae build a tapered, cylindrical case of small but coarse rock fragments. The case of A. scotti (C) is unique in having the basal quarter sharply constricted from the remainder. I n cases of A. cidoipes (Schmid) there is a ridge of small stones along each side. Length of case up to 13 m m . B I O L O G Y Larvae live i n small, cold mountain streams, often at high elevations, and frequently occur on vertical rock faces i n a thin layer o f flowing water; they also occur on rocks in turbulent streams. Gut contents o f larvae (3) we examined were largely fine organic and mineral particles, which is consistent w i t h the interpretation that Allomyia larvae graze algae from the upper surfaces of rocks. Evidently these larvae require more than one year to complete their life cycle because for several species we have collected adults and larvae of the last two or three instars at the same time. REMARKS

N o taxonomic review of Allomyia

Ross (1950, as

adults has been published since that o f

Imania).

Allomyia scotti (Oregon, Clackamas Co., 11-12 June 1967, ROM) A, larva, lateral x l 9 , tarsal claw enlarged; B, head and thorax, frontolateral; C, case, lateral x l 2 ; D, mandible, ventral; E, labrum, dorsal; F, head, ventral; G, segment IX and anal prolegs, dorsal 192

Apataniidae: AHomyia 12.1

193

12.2

Genus

Apatania

D I S T R I B U T I O N AND S P E C I E S Apatania is a genus o f some 50 species in the Holarctic and Oriental regions (Schmid 1953, 1954a). Some live in far northern arctic latitudes, and a few are circumboreal. Seventeen species are now recognized in North America, where some occur southward along the eastern and western mountain ranges to Georgia and A r i zona respectively. Larvae have been described for A. incerta (Banks) (Flint 1960) and A. praevolans Morse (Chen 1992) in the east, and for one western species, A. arizona Wiggins (1973c). Larvae are k n o w n for three northern species: A. crymophila M c L . (Lepneva 1966); A. stigmatella (Zett.) (Flint 1960; Lepneva 1966); A. zonella (Zett.) (Lepneva 1966). We associated the larva for t w o other western species, A. shoshone Banks and A. tavala Denning, and have collections o f larvae from much o f the continent. M O R P H O L O G Y Larvae of Apatania can be distinguished from any other genera in North America by absence of the metanotal sa 1 sclerites and arrangement of those setae in a linear transverse band (B). Mandibles have an entire, scraping edge (D); and the head bears many secondary setae (F). Length o f larva up to 7.5 m m . C A S E The larval case (C) is constructed of rock fragments, slightly curved dorsoventrally and tapered strongly from front to rear; i n some species larger pieces are arranged along each side. Final-instar larvae extend the dorsal edge o f the anterior opening to overhang the ventral edge, resulting i n the characteristic Apatania pupal case i n which the anterior opening is on the ventral surface. Length of larval case up to 9.5 m m . B I O L O G Y Larvae are inhabitants of cool waters; eastern and western montane species usually occur i n spring streams, but at far northerly latitudes larvae occur i n deeper waters of lakes. The Holarctic species Apatania zonella was recorded from Lake Hazen, Ellesmere Island ( 7 1 ° 1 8 ' W , 8 1 ° 4 9 ' N ) , where females greatly outnumbered males and were believed to reproduce parthenogenetically for the most part (Corbet 1966). Similar observations on other species o f Apatania i n Denmark (Nielsen 1950) indicate that this phenomenon occurs at more southern latitudes as well. Larvae of Apatania graze diatoms and other algae from the upper surfaces o f rocks (Nielsen 1942, 1943a; Lepneva 1966). B i o l ogy of the European A. muliebris M c L . was studied by Elliott (1971). Larvae of a European species produce a secretion from a gland in the dorsal part of the prothorax that has a paralysing effect on insect predators such as Rhyacophila larvae (Wagner et al. 1990). R E M A R K S Taxonomy of adults in Apatania was reviewed by Schmid (1953, 1954a); this genus has often been treated under the name Radema.

Apatania arizona (Arizona, Coconino Co., 4 July 1966, ROM) A, larva, lateral x l 4 , claws of tarsus and anal proleg enlarged; B, head and thorax, dorsal; C, case, ventrolateral x l O ; D, mandible, ventral; E, labrum, dorsal; F, head, dorsal; G, head, ventral; H, segment IX and anal prolegs, dorsal 194

Apataniidae: Βpatania 12.2

195

12.3

Genus

Manophylax

D I S T R I B U T I O N AND S P E C I E S This genus was established for a single species M. annulatus Wiggins from a mountain stream i n Idaho; a fully associated series was collected, and larvae, pupae, and adults described elsewhere (Wiggins 1973c). A n eastern species, M. altus (Huryn and Wallace 1984) from North Carolina is now included; this species was originally described under Madeophylax, now a junior synonym of Manophylax (Gall and Wiggins, i n press). M O R P H O L O G Y Larvae o f Manophylax have a general similarity to Allomyia and Apatania, a l l three having mandibles w i t h a continuous scraping edge (D), tarsal claws w i t h elongate basal setae (A), and a labrum w i t h the anterior margin membranous (F). The pronotum i n Manophylax is enlarged (B) as i n Apatania. Chloride epithelia are present on the venter o f segments n i - V i i ; the anal claw has a well-developed accessory claw i n M. annulatus (A), which is lacking i n M. altus. Larvae of Manophylax bear an elliptical sclerite on the venter of abdominal segment I (E); the sclerite has a central unsclerotized area in M. annulatus, but is entire i n M. altus. I n M. annulatus several abdominal segments have single gills and a lateral fringe; gills and fringe are lacking i n M. altus. Length of larva up to 8 m m . C A S E The larval case in Manophylax is constructed o f rock fragments, somewhat depressed, strongly tapered, and slightly curved (C); small stones may be added laterally, and small twigs and leaf fragments are attached to the dorsolateral surfaces of the case presumably as camouflage. Filamentous algae appear to grow on the cases. Length of larval case up to 10 m m . B I O L O G Y Colonies o f both species o f Manophylax are exceedingly localized (Greek manos, rare). Observations to date indicate that larvae live in hygropetric habitats - a thin f i l m of water flowing over inclined rock surfaces in small spring runs.

Manophylax annulatus (Idaho, Idaho Co., 4 June 1968, ROM) A, larva, lateral x l 8 , claws of tarsus and anal proleg enlarged; B, head and thorax, dorsal; C, case, ventrolateral x9; D , mandible, ventral; E, segment I , ventral; F, labrum, dorsal; G, head, ventral; H , segment I X and anal prolegs, dorsal 196

Apataniidae: M a n o p h y l a x 12.3

197

12.4

Genus M o s e l y a n a

D I S T R I B U T I O N AND S P E C I E S

This is an unusual endemic Nearctic genus; a single

species, M. comosa Denning, is known from Oregon. We collected an associated series o f larvae on Marys Peak in Oregon; description and analysis of characters o f larvae, pupae, and adults are available elsewhere (Wiggins 1973c). M O R P H O L O G Y The head is rounded i n dorsal aspect and bears secondary setae ( B ) ; the labium is entirely sclerotized ( E ) , and the mandibles toothed ( D ) . The pronotum is inflated, the mesonotal plates unusually wide, and the metanotum has many setae arising between the primary sclerites ( B ) ; basal setae of the tarsal claws are short (A). Sclerotized parts o f the head and thorax are uniform brownish red. A b d o m i n a l gills are lacking as is a lateral fringe o f filaments, but a tuft of setae is present laterally on segment V I I I ; chloride epithelia are apparent, though faint, both dorsally and ventrally on some segments; the dorsal sclerite of segment I X and the lateral sclerite of the anal prolegs are heavily setate (G). Length o f larva up to 7 m m . C A S E The larval case (c) is constructed of fine rock fragments, strongly tapered and curved, the posterior end obstructed with marginal silken points radiating toward the centre; a silken layer covers the exterior surface o f the case. Length of larval case up to 8.5 mm. B I O L O G Y Larvae were found in the water-saturated organic muck of a spring seepage area; careful searching failed to produce any larvae in a small spring stream 2 m away from the seepage area. Gut contents of larvae (3) were largely vascular plant pieces, algae, and fine particles of both organic and inorganic origin. Pupae and adults were taken in June; many larvae of late instars were active at the same time, suggesting an extended emergence period or a life cycle of more than one year.

Moselyana

comosa (Oregon, Benton Co., 14-15 June 1968, R O M )

A , larva, lateral x 2 1 , claws of tarsus and anal proleg enlarged; B, head and thorax, dorsal; C, case, lateral x l 3 ; D , mandible, ventral; E, labrum, dorsal; F, head, ventral; G , segment I X and anal prolegs, dorsal 198

Apataniidae: Moselyana

12.4

199

12.5 Genus Pedomoecus D I S T R I B U T I O N AND S P E C I E S Pedomoecus is another of the unusual Nearctic genera recently transferred from the Limnephilidae to the Apataniidae (Gall and Wiggins, in press). A single species, P. sierra Ross, has been recorded from California, Oregon, and Washington; we collected adult specimens from British Columbia and Alberta. Association of these unusual larvae with adults o f Pedomoecus has been inferred for many years; positive identity was recently established by W . K . Gall through field w o r k in Oregon. M O R P H O L O G Y Pedomoecus larvae have a number of unusual characters. M a n y of the primary setae on the anterior part of the head are exceptionally stout and their alveolar bases swollen ( B ) ; the labrum bears three dorsal tubercles, and the blade o f each mandible appears to be extended as a scraper but is toothed at the apex ( D ) . The pronotum is broad anteriorly i n dorsal aspect ( B ) , and a transverse internal ridge is incomplete dorsally (A, B ) ; the prosternum bears an ovoid sclerite and the prosternai horn is well developed ( E ) . Each mesonotal plate is subdivided longitudinally into two sclerites. Metanotal sal sclerites are lacking, and setae are abundant on the dorsum. The fore and middle femora bear a ventral row of short, stout setae; the hind femur is heavily setate ventrally and the hind tibia and tarsus bear long, stout setae on the dorsal edge; the basal seta o f each tarsal claw (A) extends nearly to the tip of the claw. Gills are single, and the first three abdominal segments are heavily setate. The anal claw bears an accessory hook (F). Length of larva up to 8.5 m m . C A S E The larval case is constructed o f small rock fragments and tapers strongly posteriorly; the posterior opening is reduced to a small central hole (C). Length of larval case up to 7 m m . B I O L O G Y We have collected larvae in cool, rapid streams. The unusual morphological features suggest that the larvae have some specialized way of life, not yet understood. REMARKS

Diagnostic characters for the male of P. sierra were given by Ross (1947).

Pedomoecus sierra (California, Shasta Co., 17 Sept. 1946, ROM) A, larva, lateral x l 9 , tarsal claw enlarged; B , head and thorax, dorsal; C, case, lateral x l 5 ; D , mandible, ventral; E, prothorax, ventral; F, segment I X and anal prolegs, dorsal 200

Apataniidae: Pedomoecus 12.5

201

This page intentionally left blank

13 Family Beraeidae

The Beraeidae are a small family sparsely distributed over the Holarctic region. Only the single genus Beraea

occurs i n North America, and it is confined to the eastern part o f the

continent, where colonies are exceedingly local. Larvae of the Holarctic genera differ somewhat structurally (Wiberg-Larsen 1979), but apparently are consistent i n marked reduction o f the lateral sclerite of the anal proleg (Fig. 13.1A, D), which is usually extended posteriorly as a lobe bearing a single stout seta; the mesal surface of the base o f the anal claw is membranous and bulbous, and bears a characteristic prominent brush o f 25-30 slender setae. Beraeid larvae also have a ridge along each side o f the head, the antennae arising near the end at the anterior margin o f the head. The abdomen lacks a lateral fringe o f filaments; forked lamellae may or may not be present on segment V I I I i n Beraea,

but a line o f serrate lamellae extends along the side of segments I I I to v u . Segment

I X is without a dorsal sclerite. Larvae o f North American representatives o f the Beraeidae are small, approximately 6.6 m m i n length, although those o f some European species are up to 9 m m long. Larval cases are constructed o f sand grains, and are curved and tapered. Beraeids live in small streams and springs where they are detritivorous; some European species live i n wet leaves and moss above the water line. Larvae o f the Nearctic species are confined to wet organic muck around spring seepage areas.

203

13.1 Genus Beraea D I S T R I B U T I O N AND S P E C I E S Several species o f Beraea are known from Europe, North Africa, and Asia. I n North America the genus is known only from the east, and colonies are rare: Beraea gorteba Ross occurs i n Georgia; B. nigritta Banks in New York is inadequately defined; and B. fontana Wiggins i n southern Ontario might be the same as B. nigritta. I n North America larvae are known for B. fontana (Wiggins 1954), and B. gorteba (Hamilton 1985). MORPHOLOGY Larvae of Beraea are characterized by a sharp carina extending obliquely across the pronotum, terminating in a rounded lobe at each anterolateral corner. The head bears a ridge along each side. The mesonotum bears only a lightly sclerotized and pigmented plate which lacks a mid-dorsal ecdysial line (B); the metanotum lacks sclerites, and an anterior patch of setae is continuous across the median line representing sa 1 perhaps combined w i t h sal, and sa3 is a small patch of setae on each side. Sclerotized parts are for the most part brownish orange in colour. Length of larva up to 6.6 m m . C A S E Larval cases k n o w n for species o f Beraea are constructed of fine sand grains, curved and tapered, and the exterior surface is smooth. Length of larval case up to 10 m m . B I O L O G Y Larvae o f B. fontana live in wet organic muck around spring seepage areas, but evidently not i n the exposed waters of the spring run itself (Wiggins 1954). The larval habitat of B. gorteba is similar (Hamilton 1985). This type of habitat is unusual for T r i choptera, but is of some interest because it is also exploited by larvae of Moselyana, Lepania, and Goereilla, which are western North American relict genera. Gut contents o f B. fontana larvae (2) were almost entirely vascular plant tissue and fine organic particles; similar contents and fungal mycelia were found in B. gorteba (Hamilton 1985). Emergence of adults is evidently confined to late spring; collection of the last three larval instars during this same period indicates that at least two years are required for completion of the life cycle. REMARKS

Taxonomic data and references for identification of adults were given by

Wiggins (1954).

Beraea fontana (Ontario, Durham Co., 12 A u g . 1953, ROM) A, larva, lateral x29, serrate lamellae and anal proleg enlarged; B, head and thorax, dorsal; C, case x l 8 ; D, anal prolegs, ventral 204

Beraeidae: Beraea 13.1

205

14 Family Brachycentridae

This family is widespread over the Holarctic and Oriental regions. A l l five genera now recognized i n the Brachycentridae occur i n North America, and three are endemic. Representatives of the Brachycentridae occur in most parts o f the continent, and approximately 30 species are known. Brachycentrids live i n running waters, ranging from cold mountain springs to the slowly flowing channels of marshy rivers. In small streams larvae are usually concealed in moss, but i n larger rivers the larvae fix their cases to exposed substrates in the current. Species of these larger rivers are often locally abundant. Larvae o f this family are unique among the portable-case makers (Integripalpia) i n having no dorsal or lateral humps on the first abdominal segment. From a comparative study of the musculature controlling the humps, Fuller et al. (1991) inferred that this is a p r i m i tive condition; i f so, the Brachycentridae would be especially important in interpreting the evolution o f the portable-case makers. The head frequently bears a dorsolateral carina along each side; the ventral apotome is more or less quadrate, although o f differing proportions i n various genera, and always separates the genae completely. The mandibles have tooth-like points. The pronotum usually has a central, transverse ridge, or in some genera a sulcus; a short prosternai horn is present i n some genera (Fig. 14.4D), but the horn is lacking i n others. Each mesonotal plate is frequently subdivided longitudinally by narrow sutures; metanotal sa 1 is represented only by a single seta or none at all, but a sclerite is not present. Setae on abdominal segment I are sparse or absent. Abdominal gills are single, multiple, or lacking, and the lateral fringe is reduced or absent; small forked lamellae occur on several segments. A sclerotized brown band occurs on the base of the anal proleg on each side of the anal opening i n Adicrophleps, Brachycentrus, Eobrachycentrus, and Micrasema, but is lacking i n Amiocentrus (Chapin 1978). Larval cases are made of plant or rock materials, although one frequently finds specimens i n some genera where a sizeable part of the case is of silken secretion alone. Foursided cases are characteristic of several genera i n this family. A hypothesis o f phylogeny for the genera has been proposed by Flint (1984). 206

Key to Genera* 1

Middle and hind legs long, femora approximately same length as head capsule (Fig. 14.3A), tibiae produced distally into prominent process from which stout spurs arise (Fig. 14.3E). Widespread 14.3 Brachycentrus Middle and hind legs shorter, femora much shorter than head capsule (Fig. 14.2A), tibiae not produced distally into prominent process, although spurs arise from about same point on unmodified tibiae (Fig. 14.2F) 2

2

( 1 ) Ventral apotome of head longer than wide, somewhat narrowed at posterior end, larva with very short prosternai horn (Fig. 14.4D); case 4-sided, composed of short lengths of plant material placed transversely with loose ends often protruding (Fig. 14.4c) 3 Ventral apotome of head usually wider than long (Fig. 14.2D), sometimes squarish (Fig. 14.5D); larva without prosternai horn; case cylindrical, composed of lengths of plant material wound around the circumference (Fig. 14.5c), or partially of silk (Fig. 14.2c), or of sand 4

3

(2) Each half of mesonotal plate largely entire, lateral quarter partially delineated by variable suture, posterior margin of mesonotum raised and coloured dark brown (Fig. 14.4B). Western 14.4 Eobrachycentrus Each half of mesonotal plate subdivided into three separate sclerites, posterior margin not conspicuously raised or coloured (Fig. 14.1B). Eastern 14.1 Adicrophleps

4

(2) Transverse ridge of pronotum extended to edge of prontoum (Fig. 14.5A); mesonotal sal usually with many setae extending along anterior border of sclerite, merging with sa3 (Fig. 14.5B), but sal a single seta in some species; sclerotized band on each side of anal opening (Fig. 14.5F). Widespread 14.5 Micrasema Transverse ridge of pronotum not reaching edge of pronotum (Fig. 14.2A); mesonotal sal with only single seta (Fig. 14.2B); sclerotized band lacking from each side of anal opening. Western 14.2 Amiocentrus

*See qualifications under Use of Keys, p. 7. 207

14.1 Genus Adicrophleps D I S T R I B U T I O N AND S P E C I E S single species, A. hitchcocki

The genus is known only from North America, where a

Flint, was described from Connecticut.

Larvae were associated w i t h adults i n Pennsylvania, and other larvae were collected in Maryland (Wiggins 1977). M O R P H O L O G Y A m o n g North American brachycentrids, larvae of Adicrophleps are similar only to those o f the western Eobrachycentrus. The head o f A. hitchcocki has lightcoloured muscle scars and bears a pair o f longitudinal ridges along the anterolateral margins of the frontoclypeal apotome (B, D); the ventral apotome is longer than wide (E). A transverse ridge crosses the pronotum and a short prosternai horn is present. Each mesonotal sclerite is subdivided into three parts, and the posterior margin is neither raised nor coloured. Abdominal gills are lacking; the lateral fringe is absent (A), but forked lamellae are present. Length of larva up to 6 m m . CASE

Larval cases in Adicrophleps

are four-sided, tapered, and constructed of pieces o f

moss arranged transversely (C); trailing ends frequently left attached to the moss pieces give the case a furry appearance. The posterior opening is circular. Length of larval case up to 7 m m . B I O L O G Y Larvae were collected in several cold, rapid streams 1 to 10 m wide from aquatic moss (Scapania) in riffle areas at depths not exceeding 30 cm; they were exceedingly difficult to find i n the moss. Our collections indicate a single generation per year: final-instar larvae and pupae i n M a y ; adult emergence in spring and early summer; and early-instar larvae from July to October. Gut contents from larvae (2) examined were largely vascular plant tissue with some fine organic particles. R E M A R K S Taxonomic data for the adult were given by Flint (1965). Our observations on the larval association and biology o f this species have been greatly aided by Janice M . Glime, who first found the secretive larvae i n her study of aquatic mosses as habitats for aquatic insects (Glime 1968).

Adicrophleps

hitchcocki

(Pennsylvania, Potter Co., 20 A p r i l 1968, ROM)

A, larva, lateral x23; B, head and thorax, dorsal; C, case x l 8 ; D, head, anterior, mouthparts shaded; E, head, ventral 208

Brachycentridae:

Adicrophleps 14.1

209

14.2 Genus Amiocentrus D I S T R I B U T I O N AND S P E C I E S This genus comprises a single species, A. aspilus (Ross), widely distributed in western North America: British Columbia, California, Colorado, Idaho, Montana, Oregon, Utah, and W y o m i n g . The larva was associated and described elsewhere (Wiggins 1965). M O R P H O L O G Y Larvae are generally similar to those in Micrasema, but usually can be distinguished by the single seta o f mesonotal sal (B). A single seta also occurs in the sal position in some Micrasema; but the transverse ridge on the pronotum in Amiocentrus does not reach the margin (A) as i t does in Micrasema. Each primary mesonotal sclerite is subdivided longitudinally, the two parts o f each sclerite separating at ecdysis. Distal ends of the meso- and metatarsi are extended into angulate lobes ( F ) . The head bears a carina along each anterolateral margin; the ventral apotome is wider than long ( D ) . Sclerotized parts are yellowish to light reddish brown. Single gills are present on some abdominal segments (A); the lateral fringe o f bifid filaments is lacking but forked lamellae occur on most segments. Length o f larva up to 10 m m . C A S E Larval cases i n Amiocentrus taper from front to rear but are straight. As in Micrasema, thin pieces of plant materials are wound transversely around the circumference and incorporated into a lining o f silk, although frequently much o f the case is of silk alone. Larval cases i n Amiocentrus are characterized by the lack o f any silken restriction around the edge o f the posterior opening (c). Length o f larval case up to 16 m m . B I O L O G Y The larvae are mainly characteristic o f larger streams where they live in moderate currents on rooted aquatic plants and in moss on rocks. Gut contents of larvae (2) examined were largely diatoms and fine particulate matter. Anderson (1967b) studied the biology o f A. aspilus in Oregon. REMARKS

Taxonomic discussion and references for the adult stage were given by W i g -

gins (1965).

Amiocentrus aspilus (Oregon, Jefferson Co., 18 June 1968, ROM) A , larva, lateral x l 8 ; B , head and thorax, dorsal, detail o f mesonotum; C, case x9; D , head, ventral; E , fore leg, lateral; F, middle leg, lateral; G , segment I X w i t h anal prolegs, dorsal 210

Brachycentridae:

Amiocentrus 14.2

211

14.3 Genus Brachycentres D I S T R I B U T I O N AND S P E C I E S Species of Brachycentrus occur in North America, Europe, and Asia; thirteen species are now known from this continent, and larvae have been identified for twelve o f them (Flint 1984). The group is common and widely distributed throughout the continent. M O R P H O L O G Y Larvae o f Brachycentrus have unusually long middle and hind legs (A), w i t h a fringe of short setae along the ventral edge of the femur, tibia, and tarsus, presumably functioning as a filtering device; the tibiae are produced distally into a prominent process bearing sharp spurs ( E ) . The head i n Brachycentrus larvae is patterned i n contrasting colours or is uniformly dark depending on the species, and often bears a short anterolateral carina along each side ( B ) . I n at least some species a short prosternai horn is present. A b d o m i n a l gills are single or multiple; on each segment the lateral fringe is confined to the posterior part of the lateral line, and forked lamellae to the anterior part (A). A finger-like lobe occurs on the venter of each anal proleg (G). Length o f larva up to 11 m m . C A S E Typically, larval cases o f Brachycentrus spp. are four-sided, tapered, and constructed of narrow pieces of plant material arranged transversely (C). Occasionally, some or all of the case is of silken secretion, but some cases are constructed entirely of small rock fragments (Flint 1984, figs. 1-3). Length of larval case up to 17 m m . B I O L O G Y Brachycentrus larvae are restricted to running waters. Larvae position themselves by fastening the ventral lip of the case w i t h silk to rock or plant substrate with the anterior opening facing into the current; their long middle and hind legs are extended to each side o f the case for filtering food particles carried by the current. In addition to filterfeeding, larvae graze by scraping peri phytic algae off the substrate (Gallepp 1974a). Studies indicate that the larvae ingest diatoms, filamentous algae, vascular plant detritus, and other insects (Mecom and Cummins 1964; M u r p h y 1919). Chironomid larvae enter pupal cases o f B. occidentalis by making openings i n the silken closure membrane, causing death of the caddisfly when they pupate (Gallepp 1974b). Co-existence of two species o f Brachycentrus was studied by Hauer and Stanford (1986). Our observations on populations o f Brachycentrus echo (Ross) in thermal streams in M o n o County, California, reveal that at a temperature o f 15.6°C, at which few other T r i choptera are present, larvae reach exceedingly high densities; and they persist at least to 3 4 . 4 ° C in waters smelling strongly of hydrogen sulphide, although at a much lower density. REMARKS

Distribution and taxonomy for all stages of the North American species

have been studied by Flint (1984); the status o f Oligoplectrum genus to a subgenus of

Brachycentrus

americanus

was changed from that o f

Brachycentrus.

(Idaho, Bonneville Co., 9 A u g . 1961, ROM)

A, larva, lateral x l 3; B , head and thorax, dorsal; C, case x9; D , fore leg, lateral; E, hind leg, lateral; F, head, ventral; G, anal proleg, ventral 212

Brachycentridae: Brachycentrus 14.3

213

14.4 Genus Eobrachycentrus D I S T R I B U T I O N AND S P E C I E S This genus was created for the single species E. gelidae Wiggins, discovered in Oregon; we have collected additional larvae of the genus, and presumably of this species, i n British Columbia and Washington. Subsequently, Eobrachycentrus was recognized in Japan (Wiggins et al. 1985). M O R P H O L O G Y I n larvae o f Eobrachycentrus the head is round in dorsal aspect and the dorsum flattened (B); the ventral apotome is longer than wide ( D ) . The pronotum bears a transverse depression and a short prosternai horn ( D ) . On each mesonotal sclerite the lateral quarter is partially delineated by a variable suture; the posterior margin of the mesonotal sclerites is raised into a dark brown ridge. Abdominal gills are lacking, and the lateral fringe is absent; forked lamellae are present (A). Length of larva up to 12 m m . C A S E The larval case is four-sided and evenly tapered (C); it is constructed of pieces o f plant materials, largely moss, fastened transversely. Loose ends of the moss plants are left projecting, giving the case a roughened appearance. The posterior opening resembles a four-leaf clover in outline. Length of larval case up to 13 m m . B I O L O G Y Larvae live in moss growing in small, very cold spring runs of mountainous terrain. Presence of the last three instars and prepupae in a June collection indicates a life cycle o f at least two years. Guts of larvae (2) examined contained vascular plant tissue mainly, w i t h filamentous algae, and fine particles. Adults emerge i n A p r i l to crawl actively on sunny days over the still abundant snow cover. REMARKS (1965).

Taxonomic information on all stages of E. gelidae was provided by Wiggins

Eobrachycentrus gelidae (Oregon, Clackamas Co., 19 A p r i l 1964, ROM) A, larva, lateral x l 1 ; B, head and thorax, dorsal; C, case x9; D , head and part of prosternum, ventral 214

Brachycentridae: Eobrachycentrus 14.4

215

14.5 Genus Micrasema D I S T R I B U T I O N AND S P E C I E S

The genus Micrasema

is represented over a large part

of N o r t h America, Europe, and Asia. Eighteen species are currently recognized in North America, and the group is represented in most parts of the continent. Larvae have been described for M. rustic urn (Hagen) (Ross 1944) and M.

dimicki

( M i l n e ) (Wiggins 1965); we have associated material for M. burksi Ross and Unzicker, M.

scissum

M c L . , and M. wataga Ross. A key to larvae of 14 North American species was

prepared by Chapin (1978). MORPHOLOGY

Larvae are likely to be confused only with those of Amiocentrus,

but

usually can be distinguished by the multiple setae of mesonotal sal ( B ) . However, some

Micrasema

larvae have only a single seta in the mesonotal sa 1 position, as do

trus. In all Micrasema

Amiocen-

the transverse ridge on the pronotum extends to the anterior margin

(A) (Chapin 1978). Mesonotal plates are either entire ( B ) , or in some species each one is subdivided longitudinally (Ross 1944, fig. 892) much as in Brachycentrus

The head o f Micrasema

(Fig. 14.3B).

larvae is frequently flattened dorsally and carinate, and the sur-

face often pebbled ( B ) . Sclerites of the head and thorax are usually dark reddish brown i n colour, but in some species dark brown bands are contrasted against a lighter base colour of the head. I n some species o f Micrasema

the distal ends of the meso- and metatarsi are

extended into angulate lobes, as i n Amiocentrus

(Fig. 14.2F). Abdominal gills are usually

lacking (A); but occur in a few species. The lateral fringe is lacking, but forked lamellae are present; segment v m usually bears a protuberance on each side ( E ) . A brown sclerotized band occurs on each side of the anal opening ( F ) (Chapin 1978). Length of larva up to 8 m m . CASE

Depending on the species involved, the case is straight or curved, and is con-

structed of sand or of ribbon-like pieces of plant materials wound around the circumference ( c ) , or largely of silk alone. Reduction of the posterior opening of the case w i t h silk is three- or four-lobed (C) i n some species, but the opening is uniformly circular in others. Length o f larval case up to 10 m m . BIOLOGY

Larvae o f Micrasema

spp. live i n running waters, often small, cold streams,

where they are usually found on rocks i n clumps of aquatic mosses. Some European species feed on periphytic algae during the first instar, and thereafter on moss (Decamps and Lafont 1974). Biological data on larvae of North American species of Micrasema

gathered

by Chapin (1978) confirm their close association w i t h mosses. REMARKS

Taxonomic data on adults of the North American species of

Micrasema

were reviewed by Ross (1947), Ross and Unzicker (1965), and Chapin (1978).

Micrasema

sp. (Oregon, L i n n Co., 16 June 1968, ROM)

A, larva, lateral x l 9 ; B , head and thorax, dorsal, detail of mesonotum; C, case x l 3 ; D , head ventral; E , segment V I I I , dorsal; F, anal opening, caudal 216

Brachycentridae:

Micrasema 14.5

217

15 Family Calamoceratidae

This is a family o f essentially tropical and subtropical distribution through all faunal regions; northward extensions into North America have given rise to three genera w i t h five species in eastern and western parts of the continent. The North American species occur i n streams where detritus accumulates in pools and areas of slower current. Larvae o f at least one South American species live in water held in the leaf bases o f bromeliads. Evidence for some species indicates that plant detritus is the major food o f the larvae, although as in many detritivores i t may be largely the associated microorganisms that are assimilated. Calamoceratid larvae are unique i n possessing a transverse row of about 16 stout setae across the central part o f the labrum (Fig. 15.1D). The mandibles have tooth-like points. The pronotum is produced anteriorly i n all three genera, very prominently in two o f them, and the fore trochantin is hooked i n some genera. On the mesonotum, the sa3 sclerites are separate from the larger plate incorporating the other two setal areas. On the metanotum, sa 1 and sal sclerites are reduced or absent w i t h sa 1 represented by a single seta, but the

sa3 sclerite is present. Lateral humps of abdominal segment I are more ventral i n position than i n other families. Gills are branched or single, and the lateral fringe is very dense i n some genera; forked lamellae are restricted to segment VIII. Leaves and pieces o f wood are used in several unusual ways to construct portable cases. K e y to G e n e r a * 1

Pronotum w i t h anterolateral corners extended into prominent lobes (Fig. 15.1A, 2

B ) ; gills branched (Fig. 15.IE) Pronotum w i t h anterolateral corners somewhat extended but much less than

above (Fig. 15.2A, B ) ; gills single (Fig. 15.2A); case a t w i g w i t h a central cavity (Fig. 15.2c). Eastern and western *See qualifications under Use of Keys, p. 7. 218

15.2 Heteroplectron

15 2

Family

Calamoceratidae

(1) Hind legs approximately same length as middle legs (Fig. 15.3A); anterolateral extensions of pronotum pointed (Fig. 15.3B); case of several pieces of bark and leaves (Fig. 15.3c). Southwestern 15.3 Phylloicus H i n d legs approximately twice as long as middle legs (Fig. 15.1 A ) ; anterolateral extensions of pronotum rounded (Fig. 15.1B); case of two leaf pieces, dorsal piece overlapping ventral (Fig. 15.2c). Southeastern 15.1 Anisocentropus

219

15.1 Genus Anisocentropus D I S T R I B U T I O N AND S P E C I E S Most species assigned to this genus are recorded from the O l d World (Fischer 1965, 1972b), but generic affinity of the single Nearctic species A. pyraloides (Walk.) is subject to verification (O.S. Flint, pers. comm.). The larva and pupa o f A. pyraloides were described from Georgia by Wallace and Sherberger (1970). The species was recorded from Tennessee by Edwards (1966); we collected larvae in Tennessee, and have identified larvae from Delaware. M O R P H O L O G Y Sclerotized parts o f the head and thorax are light yellowish brown in colour. The pronotum is extended dorsolaterally i n a pair of truncate lobes (B). The thorax and abdomen are strongly depressed; among the North American species of the Calamoceratidae, A . pyraloides is distinctive i n this flattened form, and also in having hind legs nearly twice as long as the middle legs (A). The added length is largely a result of an extremely elongate tibia that is secondarily subdivided as in some lcptocerid larvae such as Mystacides and Triaenodes. Features of larval behaviour as yet unknown may account for these distinctive morphological characters. Length of larva up to 19 m m . C A S E Larval cases o f A. pyraloides are among the most unusual constructed by North American caddisflies. Two ovate pieces of leaves are cut and fastened together as illustrated (C). The larger piece forms a dorsal shield over a smaller ventral piece, and between the t w o is a flattened chamber for the larva. Length of larval case up to 35 m m . B I O L O G Y Observations the slow currents of small early instars occurring in logs and rocks. Evidence years.

by Wallace and Sherberger (1970) indicate that larvae live in streams in deciduous forests. The larvae are detrital feeders, the accumulations o f leaves and later instars on the undersides of from the range of larval instars suggested a life cycle of two

R E M A R K S Diagnostic characters for adults o f A. pyraloides were given by Betten and Mosely (1940). Specimens for illustration were provided by J.B. Wallace.

Anisocentropus pyraloides (Georgia, Heard Co., 18 March 1969, Univ. Georgia Coll.) A, larva, lateral x8, hind tibia enlarged; B, head and thorax, dorsal; C, case, ventral x3; D , labrum, dorsal; E, abdominal segments, dorsal 220

Calamoceratidae: Anisocentropus 15.1

221

15.2 Genus H e t e r o p l e c t r o n D I S T R I B U T I O N A N D S P E C I E S The composition o f Heteroplectron has been unclear, but the genus appears to be restricted to the Nearctic region (O.S. Flint, pers. comm.). There are two species: H. americanum (Walk.) (syn. Ganonema nigrum Lloyd) in the east from New York, New Hampshire, and Q u é b e c southward; and H. californicum M c L . in the west from California north to British Columbia. The larva of the eastern species was described by L l o y d (1921). We have many larval collections of both, and the western species, not previously described, is illustrated here. M O R P H O L O G Y The head, pronotum, and other sclerotized parts are dark brown and shiny. Anterolateral extensions of the pronotum are evident ( B ) , but less pronounced than in the other two genera. The thorax and abdomen ( A ) are cylindrical and not flattened as in Anisocentropus. Length o f larva up to 25 m m . Larvae of the two species o f Heteroplectron

western H. californicum

can be separated by the following: in the

( A ) the ventral edge of the pronotum is concave to straight, form-

ing a sharp angle where it meets the anterior margin; i n the eastern / / . americanum

the

ventral edge of the pronotum is convex, giving rise to a rounded anterolateral junction; and i n H. americanum

there is a raised, straight ridge on the lateral sclerite o f the anal pro-

leg, which is only weakly developed in H.

californicum.

C A S E Heteroplectron larvae are unusual among North American caddisflies in their use of single twigs as cases ( C ) ; a chamber is excavated through the centre, open at both ends for circulation o f water and lined w i t h silk ( L l o y d 1921). On two occasions in California we collected larvae of H. californicum that were using stone cases of other caddisflies, but small pieces of wood were added to the anterior end. B I O L O G Y Although characteristic of cool, running-water habitats, larvae are largely confined to pools and areas of slower current where plant detritus accumulates. Observations on the life cycle of H. californicum were given by Winterbourn (1971a) and Anderson and Wold (1972); larvae ingested leaf fragments. The life history of H. americanum i n the east was studied by Patterson and Vannote (1979). REMARKS

Diagnostic characters of adults were illustrated by K i m m i n s and Denning

(1951) for H. californicum,

Heteroplectron

californicum

and by Betten (1934) for H.

(California, Plumas Co., 5 Oct. 1966, R O M )

A , larva, lateral x8; B , head and thorax, dorsal; C, case x4 222

americanum.

Calamoceratidae: Heteroplectron 15.2

223

15.3 Genus Phylloicus D I S T R I B U T I O N AND S P E C I E S This is essentially a Neotropical genus, w i t h two species recorded from the southwestern United States: P. o mat us (Banks) from Texas and P. aeneus (Banks) (syn. Notiomyia mexicana (Banks)) from Arizona. A circumstantial association for the larval diagnosis presumed by Ross (1959) was confirmed by Flint (1964b) for a Puerto Rican species o f Phylloicus; larvae of P. aeneus were reared i n Arizona (Wiggins 1977). M O R P H O L O G Y The long, pointed anterolateral processes of the pronotum (B) w i l l readily distinguish larvae belonging to this genus. The hind legs are approximately the same length as the middle legs, and the hind tibia is not secondarily subdivided as it is in Anisocentropus (A). The thorax and abdomen are somewhat flattened but not as much as in Anisocentropus. Sclerotized parts are medium to dark brown in colour. The maxillary lobes are prominent (D), the mental sclerite is long, and the submental sclerites are fused. Length of larva up to 22 m m . C A S E Larval cases are flattened and straight, consisting of dorsal and ventral halves fastened together along the edges and enclosing a central chamber (c). Pieces of bark, wood, or stout leaves are used as building materials, and it is not uncommon to find leaves from which circular pieces of a size appropriate for case-making have been cut. A protective hood-like piece is frequently positioned to overhang the anterior opening of the case. Length of larval case up to 40 m m . B I O L O G Y Larvae live i n running water. We found P. aeneus in abundance in small, cool streams in arid sections of Arizona. Larvae o f the last four instars, pupae, and adults from our collections made i n M a y and June indicate a life cycle of more than one year. Gut contents from a sample of these larvae (2) were primarily filamentous algae and vascular plant tissue - probably from detritus. Prior to pupation larvae fasten their cases to the undersides o f logs and rocks. REMARKS

Diagnostic characters for adults of several species o f Phylloicus,

including

P. aeneus, were given by Flint (1967b).

Phylloicus aeneus (Arizona, Cochise Co., 23 June 1966, ROM) A, larva, lateral x8; B, head and thorax, dorsal; C, case, ventral x4; D, maxillae, labium and ventral apotome, ventral 224

Calamoceratidae: Phylloicus 15.3

225

16 Family Goeridae

This is a family of about 10 genera and 100 species, represented in all faunal regions of the w o r l d except the Neotropical and Australian. As now defined (Gall and Wiggins, in prep.), the Goeridae comprise four genera i n North America, where three o f them are endemic. Larvae live in running waters, ranging from small cold springs to rivers. For the most part, larvae graze algae and fine organic particles from exposed rock surfaces and have typical scraper mandibles; but larvae of Lepania are confined to water-saturated organic muck of spring seepage, and have toothed mandibles. Larvae of the Goeridae are characterized by major modifications to the thoracic nota. The pronotum is enlarged and thickened laterally; sclerotized plates o f the mesonotum are subdivided into two or three pairs of smaller sclerites, and the mesepisternum is extended anterad as a prominent process. These modifications are integrated to form a set of closefitting sclerites forming an operculum that closes off the anterior opening of the case when the larva withdraws. A transverse hump across the mesonotum, characteristic of goerid larvae, facilitates the bend i n the body required to allow the anterior part of the thorax to block the opening o f the case. Goerid larvae usually have at least some forked lamellae on several of the abdominal segments; a lateral fringe of bifid filaments is present i n some genera but lacking in others. Larvae construct cases o f rock fragments - simple tubes in some genera, but with a ridge o f larger pieces along each side in others. The posterior opening of the case is reduced w i t h silk to an unusually small opening (e.g. Fig. 16.1c), perhaps reflecting the same selective pressure as the unique anterior closure arrangement. The systematics of the Goeridae has been extensively revised, and a hypothesis of phylogeny proposed (Gall and Wiggins, in prep.); two subfamilies are represented i n North America: Goerinae and Lepaniinae. A third, Archithremmatinae, occurs i n the Far East o f Russia.

226

16 Family Goeridae Key to Genera* 1

Gills mostly three-branched (Fig. 16.1A); case of small rock fragments, usually with two larger pebbles along each side (Fig. 16.1c). Eastern and western 16.1 Goera Gills single (Fig. 16.2A), restricted to segments III and IV or in alone (Fig. 16.2A), or absent entirely (Fig. 16.3A)

2

( l ) Gills single (Fig. 16.2A)

2 3

Gills absent entirely (Fig. 16.3A); case of small rock fragments, tapered and slightly curved (Fig. 16.3c). Southeastern 16.3 Goerita 3

(2) M ese pi s tern u m laterally compressed, dorsum of pronotum flat, each metanotal sa 1 consisting of one or two setae without sclerite or with very small sclerite (Fig. 16.2B); case of small rock fragments, several larger pieces along each side (Fig. 16.2c). Western 16.2 Goeracea Mesepisternum dorsoventrally depressed, dorsum of pronotum convex, each metanotal sal consisting of several setae on a distinct sclerite (Fig. 16.4B); case of small rock fragments without lateral pieces, tapered and slightly curved (Fig. 16.4c). Western 16.4 Lepania

*See qualifications under Use of Keys, p. 7.

227

16.1 Genus Goera D I S T R I B U T I O N AND S P E C I E S Species of Goera are distributed over much of the H o l arctic and Oriental regions, and at least one occurs in South Africa. Six species are known in North America, five within the eastern half of the continent, and G. archaon Ross i n Oregon. Larvae have been described for G. calcarata Banks, G. fuscula Banks, and G. sty lata Ross by Flint (1960); we have associated series for three species, including the larva o f G. archaon (Wiggins 1977). M O R P H O L O G Y A m o n g Nearctic goerid larvae, species of Goera alone have gills of more than one filament (A). The head bears secondary setae ( D ) and usually has ridges of some form. The pronotum is thickened laterally (A), bears a pair of anterolateral processes and frequently a median ridge ( B ) . Each mesonotal plate is subdivided into separate sclerites ( B ) . Ventral as well as dorsal chloride epithelia are present (A). Length of larva up to 10.5 m m . C A S E W i t h a row of larger pebbles along each side of the central tube o f small rock fragments, larval cases of Goera (C) are similar only to those o f Neophylax i n North America. Generally, Goera cases have fewer and larger ballast stones on each side, usually two; Neophylax cases usually have smaller ballast stones, and thus more than two. Larvae o f Goera have a tendency to cover irregularities on the outside of the case with silk. The posterior opening o f the larval case i n Goera is restricted w i t h silk to a very small central hole (C). Length o f larval case normally up to 14 m m . Larval cases almost twice as long as the larva occur infrequently in collections, and reveal the behaviour by which Goera larvae enlarge their case by building a new one on the end of the existing case and finally cutting i t free. Since most caddisfly larvae increase the size o f their cases by more gradual addition of new pieces at the anterior end, casebuilding behaviour i n Goera seems to have been modified to accommodate the larger ballast stones. Similar behaviour was studied i n the related European genus Silo by Hansell (1968b). B I O L O G Y These are larvae o f running waters, where they live in the current and feed by scraping periphytic algae and fine detrital particles from exposed surfaces o f larger rocks (Coffman et al. 1971).

Goera archaon (Oregon, Benton Co., 16 A p r i l 1964, ROM) A, larva, lateral x l 6 ; B , head and thorax, dorsal; C, case x l l ; D , head, dorsal 228

Goeridae: Goera 16.1

229

16.2

Genus G o e r a c e a

D I S T R I B U T I O N AND S P E C I E S Goeracea is a Nearctic genus recorded from montane areas o f western North America: British Columbia, California, Idaho, Montana, and Oregon. Two species are known, G. genota (Ross) and G. oregona Denning. We have associated larvae for both species, and data for larvae and adults were presented elsewhere (Wiggins 1973b). M O R P H O L O G Y Larvae of Goeracea are unusual i n appearance and unlikely to be confused w i t h any other genus. The pronotum is flat and rounded in dorsal outline, and heavily thickened laterally; the mesepisternum is laterally compressed and long (A). Each metanotal sal consists of one or two setae without a sclerite or w i t h a very small sclerite. Gills are single and confined to segments III and IV or to III alone. Ventral chloride epithelia are present; and the two stout setae comprising the basal tuft o f the anal proleg arise from a small sclerite, the dorsal plate (G). Typically for the Goeridae, mandibles have scraping edges rather than distinct teeth (D), the basal seta of each tarsal claw extends nearly to the tip of the claw (A), and the anterior border of the la brum is membranous (F). Length of larva up to 6.6 m m . C A S E The larval case (C) is of rock fragments, curved and tapered, with a row of larger pebbles along each side; frequently a mid-dorsal ridge of small stones is also attached to the central tube. The silken membrane reducing the posterior opening of the case has an eccentric, relatively small opening. When the larva is withdrawn into the case, the anterior opening is closed entirely by the pronotum and the mesothoracic sclerites, and the head is folded completely beneath the pronotum. Length o f larval case up to 8 m m . B I O L O G Y Larvae of Goeracea inhabit small, cold streams i n mountainous areas where they are usually found on rocks. Gut contents of larvae (6) we examined were mainly fine organic and inorganic particles with a small proportion of vascular plant pieces.

Goeracea

genota (Oregon, Benton Co., 13 A p r i l 1964, ROM)

A, larva, lateral x26, tarsal claw enlarged; B, head and thorax, dorsal; C, case, dorsolateral x l 4 ; D, mandible, dorsal; E, head, ventral; F, labrum, dorsal; G, segment IX and anal prolegs, dorsal 230

Goeridae: Goeracea 16.2

231

16.3 Genus Goerita D I S T R I B U T I O N AND S P E C I E S The genus is confined to North America and is k n o w n only from the eastern part of the continent; there are two species, G. semata Ross and G. betteni Ross. Larvae identified circumstantially as G. semata were described by Flint (1960) and by Wiggins (1973b); larvae o f G. betteni were identified by Wiggins (1973b), and taxonomic data for adults of both species were also provided. M O R P H O L O G Y These are the only North American goerid larvae known w i t h no abdominal gills. The prominent median hump on the pronotum is distinctive, and the anterolateral processes and lateral thickening are similar to Goera (A, B ) . The antennae are set in depressions ( B ) as in several other goerid genera. Sclerotized parts are reddish brown, the head and thoracic nota having a pebbled surface. Ventral chloride epithelia are present on segments I V - V I ; the two stout setae comprising the basal tuft of the anal proleg arise from the dorsal plate ( D ) as in several other genera of the Goeridae; forked lamellae are reduced i n number, and a lateral fringe is lacking. Length of larva up to 6 m m . C A S E Larvae construct a smooth-sided case of sand grains; those of G. betteni incorporate larger pieces i n the lateral walls of the case (C), behaviour suggestive of Goeracea where a row of larger stones is added to each side of the case. The posterior opening is restricted w i t h silk to a small hole dorsad of centre. Length of larval case up to 6.5 m m . B I O L O G Y Larvae of both species occur on rocks i n small, cold spring runs in mountainous areas; colonies are exceedingly local in distribution. Gut contents of larvae (3) we examined were mainly fine organic and mineral particles, consistent w i t h the behaviour of grazing on rock surfaces. The life history and production of G. semata were studied by H u r y n and Wallace (1985); the life cycle extended over two years, and two distinct cohorts were present at any one time. Diatoms were the principal food in spring, but amorphous detritus constituted a larger proportion of the gut content at other times of the year.

Goerita betteni (Tennessee, Franklin Co., 14-15 M a y 1970, ROM 700337) A , larva, lateral x22; B , head and thorax, dorsal; C, case, ventrolateral x l 6 ; D , segment I X and anal prolegs, dorsal 232

Goeridae: Goerita 16.3

233

16.4 Genus Lepania D I S T R I B U T I O N AND S P E C I E S Lepania is an unusual Nearctic genus with a single species, L . cascada Ross, known from Oregon and Washington. Morphology of all stages was described and relationships o f the genus assessed elsewhere (Wiggins 1973b). M O R P H O L O G Y Subdivided plates of the mesonotum and an elongate mesepisternum ( B ) , along w i t h thickened lateral edges on the stout pronotum, establish the larva as a member o f the Goeridae; w i t h i n that group the larva o f Lepania is most readily distinguished by the dorsally depressed mesepisternum and the well-developed metanotal sal sclerites. Atypically, the larva o f L . cascada has mandibles w i t h separate teeth ( D ) and short basal setae on the tarsal claws (A). The head bears many secondary setae dorsally ( B ) , and the antennae are set in lateral concavities ( H ) ; the ventral apotome has concave lateral margins ( F ) . Abdominal gills are reduced to two pairs of single filaments on segment I I I (A), forked lamellae are reduced, and a lateral fringe is lacking; a small dorsal plate lies beside the basal tuft o f the anal proleg ( G ) , and the anal claw lacks an accessory hook. Length o f larva up to 5.5 m m . CASE

Larvae of L . cascada

construct a case o f small rock pieces, curved and strongly

tapered (C); rock pieces on the venter are smaller than those placed dorsally and laterally. Length o f larval case up to 5.5 m m . B I O L O G Y This exceedingly local species occurs in spring seepage sites in mountainous country. From our field observations on Marys Peak, Oregon, it is evident that larvae are restricted to the water-saturated organic muck at the head of springs. Gut contents of larvae (3) we examined were mainly pieces o f vascular plants with some algae. Adults fly in June, but the presence of early-instar larvae at the same time suggests that more than one year is required for completion o f the life cycle, as has been shown for Goerita. R E M A R K S Phylogenetic analysis of the Goeridae (Gall and Wiggins, i n prep.) reveals that the basal lineage still extant in this family is probably Archithremma of the Russian Far East; Lepania was inferred to be the next oldest lineage.

Lepania cascada (Oregon, Benton Co., 14-15 June 1968, ROM) A, larva, lateral x23, tarsal claw enlarged; B , head and thorax, dorsal, detail of mesonotum; C, case, lateral x l 8 ; D, mandible, ventral; E, labrum, dorsal; F, head, ventral; G , segments VIII, I X and anal prolegs, dorsal; H , right side o f head, dorsal 234

Goeridae: Lepania 16.4

235

This page intentionally left blank

17 Family Helicopsychidae

So abundant and widespread are these caddisflies, it is easy to forget that the larvae are among the most remarkable of all insects. Their helical cases of closely fitted rock fragments are an outstanding example o f the elegance and precision of insect behaviour. The family comprises four genera, with representatives widely distributed over most faunal regions (Schmid 1993); a single genus, Helicopsyche, occurs in North America. Aspects of the morphology and biology of a European species were outlined by Boto§aneanu (1956). Larval cases of most species resemble tightly coiled snail shells, although a Cuban species has an open-coiled case (Boto§aneanu and Sykora 1973) suggestive o f Baikalia, an unusual endemic snail genus of Lake Baikal. The case o f the most common North A m e r i can species, Helicopsyche borealis, was originally described as a snail having 'the remarkable property of strengthening its whirls by agglutinations of particles o f sand, by which it is entirely covered' (Lea 1834). The coiled case o f the Helicopsychidae must have been derived from the more usual tube-case-making behaviour; and perhaps there is some advantage for the larvae in consolidating the mass of the case. Helical cases, for example, seem well suited to interstitial habitats; larvae o f H. borealis were found to depths of 30 cm below a stream bed (Williams and Hynes 1974), and their cases proved more resistant to crushing than those of other families tested (Williams et al. 1983). Within their cases, larvae lie on one side, the abdomen coiled more dorsoventrally than laterally. A n opening on the spire of cases o f H. borealis corresponds to the posterior opening of tube-cases, facilitating water circulation through the case. Helical cases are not w h o l l y confined to the Helicopsychidae, but are also constructed by larvae i n the South African leptocerid genus Leptecho (Scott 1961).

237

17.1 Genus H e l i c o p s y c h e D I S T R I B U T I O N AND S P E C I E S This is a genus o f about 100 species represented in most faunal regions (Schmid 1993). In North America a dozen or so species are k n o w n from M e x i c o , but only four north of the Rio Grande: / / . piroa Ross in Texas; H. mexicana Banks in Arizona and Texas; H. limnella Ross in Arkansas and Oklahoma; and H. borealis (Hagen) widespread and common over much of the continent. The northern l i m i t of H. borealis is uncertain, but we have records from Saskatchewan to 5 5 ° N lat.

O f these four species, only the larva o f H. borealis has been described, by Vorhies (1909) and Elkins (1936) among others. We have many series of larvae from North America. M O R P H O L O G Y Structural features are evident i n the illustration. The fore trochantin is unusually long (A), and the comb-like structure o f the anal claw ( D ) is unique among North American larvae. Forked lamellae (E) are confined to segment v m .

C A S E The snail-like cases made o f sand grains (C, F) provide an unmistakable diagnosis for larvae o f Helicopsyche. The dorsal l i p o f the anterior opening is extended as a hood, covering the larva as i t grazes on rock surfaces. Diameter o f case up to 7 m m . B I O L O G Y Larvae o f Helicopsyche spp. are normally associated with running water, but those o f H. borealis are also common in the littoral zone of lakes. Vorhies (1909) found larvae to depths of 8-10 feet i n Wisconsin lakes. Larvae of H. borealis have an exceptionally broad temperature tolerance; we collected larvae of this species in thermal streams o f Yellowstone National Park, W y o m i n g , where temperatures ranged up to 3 4 ° C and no other caddis larvae were found. In other streams with thermal affluents i n California and Montana, Helicopsyche larvae were always among the few Trichoptera present. Experimental analysis o f thermal tolerance and feeding behaviour was carried out by Resh et al. (1984). Food of H. borealis larvae, analysed by Coffman et al. (1971) and M e c o m (1972a), consisted o f algal, detrital, and animal materials. From some studies there appears to be a continual emergence o f H. borealis adults from spring through early autumn (Ross 1944), followed by a long egg-diapause o f 5-6 months (Williams and Hynes 1974); but no evidence of diapause or extended emergence was found in a study of this species i n California (Resh et al. 1984). The biology o f H. borealis was studied in Ontario by Williams et al. (1983); larvae fed on diatoms and detritus, the proportions changing w i t h seasonal availability.

Helicopsyche borealis (Ohio, Ashland Co., A u g . 1968, ROM) A, larva, lateral x21 ; B , head and thorax, dorsal; C, case, lateral x l 6 ; D , anal claw; E, forked lamellae on segment v m , x580; F, case, dorsal 238

Helicopsychidae: Helicopsyche 17.1

239

This page intentionally left blank

18 Family Lepidostomatidae

The Lepidostomatidae are widely distributed over much of the world, primarily in the Holarctic, Oriental, and Afrotropical regions; a few species also occur in northern parts o f the Neotropical region of M e x i c o through Panama, and of the Australian region in N e w Guinea. A synopsis o f the North American Lepidostomatidae has been provided by Weaver (1988) i n which about 80 species are recognized. Genera have been unstable through much of the taxonomic history of the Lepidostomatidae. Generic characters based on the richly varied secondary sexual structures of the males led to the proposal of some 15 names in North America; these were reduced to two genera, Lepidostoma and Theliopsyche, by Ross (1944, 1946). W i t h i n the genus Lepidostoma, four subgenera were proposed by Weaver (1988) for the North American species: L. (Lepidostoma), L . (Mormomyia), L . (Neodinarthrum), and L . (Nosopus). Proposals for generic classification of the North American Lepidostomatidae have been made almost entirely on the basis of characters of the adults; little taxonomic information has been available for larvae. A key to larvae of species groups and some species was provided by Weaver (1988), based mainly on case structure and geographic distribution with some morphological information; the subgeneric groups proposed for Lepidostoma lack larval diagnoses. In an attempt to augment the proposed classification with larval diagnoses, a comparative study was made o f associated larvae of 12 North American species representing the four subgenera of Lepidostoma sens. lat. (Kerr and Wiggins 1993); detailed comparison of morphology including surface sculpture and chaetotaxy was included. From structural characters, several of the larvae could be distinguished at the species level, but diagnostic larval characters were congruent only i n two of the subgenera. Larvae of t w o species of L. (Neodinarthrum) were distinguished by pronotal surface sculpture; and two species o f L. (Lepidostoma) shared sparse secondary setation on the mesonotum. These provisional larval characters for two of the subgenera are not proposed as taxonomic diagnoses because larvae of the large majority of species of Lepidostoma sens. lat. are still unknown. There is a tendency in the classification of insects for subgenera to become genera. However, most genera o f Trichoptera now recognized in North America can be identified 241

18 F a m i l y L e p i d o s t o m a t i d a e in the larval stage. This is an important functional principle of generic taxonomy; and it can be hoped that systematists proposing changes i n the generic classification o f T r i choptera w i l l ensure that the character base includes concordant larval diagnoses (Kerr and Wiggins 1993: 119). Larvae o f the Lepidostomatidae are generally similar to those of the Limnephilidae, but are distinguished by the position o f the antennae close to the eyes, by the absence o f a median dorsal hump on abdominal segment I , and by the absence o f chloride epithelia enclosed by sclerotized oval rings on the abdominal segments. North American lepidostomatid larvae that we have examined possess a dense patch o f pectinate spines on the distal end o f the hind coxa (Fig. 18.1A). The mandibles have separate teeth, and the prosternai horn is well developed. A b d o m i n a l gills are single and arranged in dorsal and ventral rows only, or are lacking; the lateral fringe is sparse and often absent, and forked lamellae occur on several segments. Segment v m bears a broad lobe at each side. Anal papillae are usually present. The majority o f lepidostomatid larvae in North America are generally concordant with the one illustrated here as Lepidostoma.

But in some o f our collections from the west, the

density of secondary setation on meso- and metanota is much greater than in typical Lepidostoma, or the head is flattened much as i n Theliopsyche, genus Ecclisocosmoecus',

or bulbous as i n the l i m n e p h i l i d

or the pronotum is modified to resemble that i n Goera.

Different

larval cases are associated w i t h some o f these distinctive morphological characters. The typical larval case associated w i t h this family is four-sided, and constructed o f quadrate pieces o f bark and leaves (Fig. 18.1c); i n four-sided cases o f the Lepidostomatidae the component pieces are squarish, distinguishing them from four-sided cases o f the Brachycentridae in which the pieces are slender. But the North American lepidostomatid fauna also includes larvae that b u i l d several other types o f cases - o f bark and leaf pieces arranged irregularly, o f leaf pieces arranged spirally (Fig. 18. lG), o f pieces o f plant stems arranged transversely (Fig. 18.1H), and o f sand grains too (Fig. 1 8 . I F ) . These examples indicate that a good deal o f larval diversity has yet to be incorporated into the data base for Lepidostomatidae i n North America. For the present, all o f these larval types, apart from Theliopsyche,

are assigned provisionally to Lepidostoma;

larvae o f Theliopsyche

distinctive characters. It can be noted that adults o f the eastern Lepidostoma (Hagen) were assigned to the genus Goerodes

have few togatum

by Corbet et al. (1966) and by N i m m o

(1966); associated larval material o f that species i n the ROM collection indicates little discordance from typical

Lepidostoma.

Two subfamilies have been proposed for the Lepidostomatidae (Weaver 1993): L e p i dostomatinae and Theliopsychinae. The t w o are broadly similar i n global distribution, but the Theliopsychinae, now w i t h only four extant genera and 4 per cent o f the species, were a major part o f the Lepidostomatidae in Baltic amber deposits o f O l i g o c è n e age some 40 m i l l i o n years ago. Most larvae o f this family occur i n small, cold streams; i n larger rivers they tend to frequent sections o f slower current, and they are also found i n the littoral zone o f lakes. Lepidostomatid larvae are detritivorous, and are usually associated w i t h accumulations o f leaves and other plant materials.

242

K e y to G e n e r a * 1

Head usually unmodified and without carina (Fig. 18. I B ) , but carina present i n a few western species; cases o f plant pieces usually 4-sided (Fig. 18.1c), but pieces also arranged irregularly, transversely (Fig. 18.1H), or spirally (Fig. 18.1G); cases also o f sand grains (Fig. 18. I F ) . Widespread 18.1 Lepidostoma Head w i t h dorsal peripheral carina (Fig. 18.2B); cases o f sand grains. Eastern 18.2 Theliopsyche

*See qualifications under Use of Keys, p. 7. 243

18.1

Genus L e p i d o s t o m a

D I S T R I B U T I O N AND S P E C I E S Lepidostoma is primarily a Holarctic and Oriental genus to which about 75 North American species have been assigned. The group is widespread over much of the continent, although most of the species are western. Larvae have been described for few species: L . griseum (Banks) by Sibley (1926); L . liba Ross by Ross (1944); L . bryanti (Banks) (as L . wisconsinensis Vorhies) by Vorhies (1909). We have associated larval material for about 25 other species (e.g. Kerr and W i g gins 1993). M O R P H O L O G Y The larval diagnosis for Lepidostoma used in the generic key subsumes the aberrant forms referred to previously in the introduction to this family. Most North American larvae are, however, generally concordant with the one illustrated here (A-E). Length o f larva up to 12.5 m m . C A S E Cases of late-instar larvae in most species o f Lepidostoma are usually four-sided and constructed of quadrate pieces of bark or leaf (C); observations indicate that in at least some of these species early-instar cases are o f sand grains and cylindrical, with the foursided case o f bark and leaves built on the anterior end during later instars (Vorhies 1909; Hansell 1972). Final instars in some other species assigned to Lepidostoma have cases of plant materials placed spirally or transversely (G, H), or sand grains (F). Length of larval case up to 15 m m . B I O L O G Y Lepidostoma larvae most often occur in cool springs and streams, usually in areas of little current, but they are also found in lakes and in temporary streams (Denning 1958a; Mackay 1969). Food studies o f Lepidostoma larvae show that detritus comprises the major part of the materials ingested (Chapman and Demory 1963; Winterbourn 1971a; Anderson and Grafius 1975), and larvae are usually found in association with dead plant material; larvae are also attracted to dead fish (Brusven and Scoggan 1969). Life- history data published by Anderson (1967b) and Mackay (1969) show a single generation per year for five species studied, and indicate as well that there is temporal and spatial separation among larvae of different species living i n the same habitat.

Lepidostoma spp. A-E (Ontario, Hastings Co., 15 Oct. 1968, ROM) A, larva, lateral x l 7 , apex o f hind coxa enlarged; B, head and thorax, dorsal; C, case x l O ; D , eye and antenna, lateral; E, head, ventral F (Arizona, Cochise Co., 23 June 1966, ROM), case x5 G (Oregon, Clatsop Co., 14 July 1963, ROM), case x4 H (Oregon, Douglas Co., 4 July 1961, ROM), case x5 244

Lepidostomatidae: Lepidostoma 18.1

245

18.2

Genus T h e l i o p s y c h e

D I S T R I B U T I O N A N D S P E C I E S The genus Theliopsyche is represented only in the eastern part of the Nearctic region, where six species are recorded: Tennessee, North Carolina, New Jersey, N e w York, New Hampshire, and Q u é b e c . The species are exceedingly local in occurrence. The larval diagnosis for Theliopsyche is based on a single species, T. melas Edwards, that we associated at the type locality i n Tennessee (Wiggins 1977), and on several other series o f larvae provided by C.R. Parker. M O R P H O L O G Y The genus is consistent with others of the family i n having larvae w i t h antennae situated close to the eye, with abdominal gills i n single filaments, and lacking a median dorsal hump on abdominal segment I (A, B ) . I n the larvae studied the dorsum of the head is flattened and bordered by a peripheral carinate ridge that is particularly pronounced laterally; although this character separates the genus from most Lepidostoma larvae, we have collected in western North America several series of larvae, here assigned to Lepidostoma, in which the head is also dorsally flattened. The length of the ventral apotome o f the head (Wiggins 1977) has proved to be unreliable for distinction between the two genera. Length o f larva up to 6.5 m m . CASE

The larval case ( C ) is of smooth outline, constructed of fine rock fragments,

curved, and slightly tapered. Length of larval case up to 7 m m . B I O L O G Y Larvae and pupae of T melas were collected in the clean gravel bed of a small spring run. Localities for other species of Theliopsyche indicate that they live in similar habitats.

Theliopsyche melas (Tennessee, Franklin Co., 14-15 M a y 1970, ROM 700337) A , larva, lateral x 2 1 ; B , head and thorax, dorsal; C, case x l 5 ; D, head, ventral; E, sclerite of segment IX, dorsal 246

Lepidostomatidae: Theliopsyche 18.2

247

This page intentionally left blank

19 Family Leptoceridae

The Leptoceridae are a large and flourishing family represented in most of the world's faunal regions. Approximately 1 0 0 species are known in Canada and the United States in eight genera; they are common and widespread as a group and often abundant locally. Almost all Nearctic leptocerid larvae can be distinguished by their long antennae; the exceptions are some sponge-feeding species o f Ceraclea i n which the antennae have probably become secondarily shortened. Leptocerid larvae are further distinguished by additional unpigmented lines of weakness where primary sclerites of the head and thorax usually subdivide at ecdysis. A l l of the Nearctic larvae of the family have a subocular line along each side o f the head, and some species o f Ceraclea have an additional supraocular line (Fig. 19. I D ) ; there are pronotal lines of weakness in Leptocerus, Mystacides, and Nectopsyche. One advantage o f secondary separation of these sclerites might be that they are more easily ejected from the posterior opening of the pupal case after larval-pupal ecdysis, a rather unusual aspect to the behaviour of most Leptoceridae. Because of this behaviour, the metamorphotype method for larval association cannot be used in the Leptoceridae; however, Haddock ( 1 9 7 7 ) found in Nectopsyche that about 1 0 per cent of the pupae reared did not void the larval exuvial sclerites, and this information on larval morphology could be retrieved. The hind legs of leptocerid larvae are much longer than the others, and the segments somewhat modified: the trochanter is lengthened, the femur is subdivided into a short proximal and a longer distal section, the tibia is lengthened and often subdivided into t w o parts by a constriction near the middle, and in some genera the tarsus is similarly subdivided. The mesonotal plates are lightly sclerotized and frequently have little colour. The metanotum is largely membranous, sa3 is usually present, sal and sal variously reduced or modified. Humps of the first abdominal segment are present, but often not prominent; characteristic spinose sclerites occur on the lateral humps i n some genera. Abdominal gills are usually single, sometimes in groups or lacking. The lateral fringe is usually present, though reduced, and forked lamellae are confined to segment VIII. Segment IX bears a small dorsal sclerite w i t h setae. Spines occur on the base of the anal prolegs i n some genera. 249

19 Family Leptoceridae Leptocerids have penetrated most types of warmer, permanent waters in North America. Larvae of most genera seem to be omnivorous feeders, but specialization as predators is evident in the mandibles of Oecetis. In several genera larvae swim through the water carrying their cases, setal fringes on the long hind legs improving their effectiveness as paddles. Since those seen to swim most often - Leptocerus and Triaenodes - are usually residents of plant beds near the surface of relatively deep waters, it seems likely that swimming is a means of dispersing to food resources through the upper levels independent of the bottom substrates to which most other trichopteran larvae are restricted. Larval cases are of several types and materials, but over all the architecture is characteristic for each genus. Taxonomic problems in the genera of the Leptoceridae have made the biological literature on these insects difficult to interpret. Much of the uncertainty arises from broad application of the name Leptocerus to groups such as Athripsodes and Setodes, which in recent years have been more narrowly defined. Taxonomic refinement has continued with the recent segregation of Ceraclea from Athripsodes (Morse 1975); a second major nomenclatural change in the North American leptocerids is synonymy of Leptocella with Nectopsyche (Flint 1974c). Two subfamilies are recognized: the Triplectidinae which are not represented in North America; and the Leptocerinae to which all of our genera are assigned. Classification of the North American genera to tribe is as follows (Morse 1981). Athripsodini: Ceraclea; Leptocerini: Leptocerus; Mystacidini: Mystacides; Nectopsychini: Nectopsyche; Oecetini: Oecetis; Setodini: Setodes; Triaenodini: Triaenodes, Ylodes. Diagnostic characters for these tribes are derived principally from adults (Morse 1981); larval characters will be among those listed here under the generic headings, for the most part. Key to Genera* 1

Middle legs with tarsal claw hook-shaped and stout, tarsus curved (Fig. 19.2A); case of transparent silk, slender (Fig. 19.2c). Northern and eastern 19.2 Leptocerus Middle legs with tarsal claw normal, slightly curved, and slender, tarsus straight (Fig. 19.1A)

2

2

(1) Anal prolegs with sclerotized, concave plate on each side of anal opening, each plate with marginal spines, and extended into ventral lobe (Fig. 19.6G); case cylindrical, of small stones (Fig. 19.6c). Eastern 19.6 Setodes Anal prolegs without sclerotized spiny plates as above, although patches of spines or setae may be present (Fig. 19.7A, E)

3

(2) Labrum with many secondary setae (Fig. 19.5D); maxillary palpi usually extended far beyond anterior edge of labrum, mandibles usually elongate and

*See qualifications under Use of Keys, p. 7.

250

3

19 F a m i l y L e p t o c e r i d a e blade-like with sharp apical tooth separated by gap from remainder of teeth (Fig. 19.5E); cases o f several types and materials. Widespread 19.5 Oeeetis Labrum with primary setae only, scattered secondary seta lacking (Fig. 19.3B); maxillary palpi extended little, i f any, beyond anterior edge o f labrum, mandibles short and wide, teeth grouped closely together around central concavity (Fig. 19.3D) 4 4

(3) Mesonotum with pair o f dark, curved bars on weakly sclerotized plates (Fig. 19.1B); abdomen disproportionately thick, gills usually in clusters (Fig. 19.1A); cases o f several types and materials. Widespread 19.1 Ceraclea Mesonotum without pair o f dark bars on plates, abdomen more slender, gills single or entirely absent (Fig. 19.4A, B )

5

5

(4) Ventral apotome o f head triangular (Fig. 19.4E) or not apparent; tibia o f hind leg usually without middle constriction and no apparent subdivision (Fig. 19.4A)

6

Ventral apotome o f head rectangular (Fig. 19.7D); tibia of hind leg w i t h constriction near centre, apparently d i v i d i n g it into two parts (Fig. 19.7A) 7 6

(5) Base o f each anal proleg w i t h only ventral band o f small spines on each side o f anal opening (Fig. 19.4F), or without spines i n this position; case long and slender, o f various materials. Widespread 19.4 Nectopsyche Base of each anal proleg w i t h ventral patch o f longer spines i n addition to band of small spines (Fig. 19.3F) 7

7

(5, 6) H i n d legs with a few scattered long setae (Fig. 19.3A); metanotal sal w i t h single seta (Fig. 19.3B); case irregular, o f plant and rock materials (Fig. 19.3c). Widespread 19.3 Mystacides H i n d legs usually w i t h close-set fringe o f long setae (Fig. 19.7A); metanotal sal lacking (Fig. 19.7B); case long, slender spiral of plant pieces (Fig. 19.7c). 8

8

(7) Head usually with dark dorsal muscle scars on lighter b r o w n background; posterior margin o f head capsule w i t h narrow, cream-coloured crescentic band (Fig. 19.8B). Northern and western 19.8 Ylodes Head variously pigmented dorsally w i t h two dark bands (Fig. 19.7B) or dark muscle scars on lighter b r o w n background; posterior light crescent usually lacking, but i f present, irregular i n outline along posterior margin o f head capsule. Widespread 19.7 Triaenodes

251

19.1 Genus Ceraclea D I S T R I B U T I O N A N D S P E C I E S A l l North American species formerly assigned to Athrlpsodes have been transferred to Ceraclea, a genus of Holarctic, Oriental, and Ethiopian distribution (Morse 1975). Approximately 36 species are known on this continent, and the group as a whole is widespread and common. The larvae o f C. ancylus (Vorhies) and C. diluta (Hagen) were described by Vorhies (1909), and that o f C. cancellata (Betten) by Elkins (1936). Diagnostic characters for larvae of 11 species were given by Ross (1944); descriptions and keys to larvae o f 19 species were given by Resh (1976). M O R P H O L O G Y Larvae o f Ceraclea ( A ) are stout-bodied, the first abdominal segment widest and the abdominal gills usually in clusters. The ventral apotome of the head is crescent-shaped and wider than long (E). I n some species a parafrontal area is delimited between each frontoclypeal arm of the dorsal ecdysial line and a lightly pigmented supraocular line ( B , D ) . Most species associated w i t h freshwater sponges lack supraocular lines but apparently all of them have short antennae ( F ) , the latter modification probably facilitating their burrowing i n sponge colonies. Mandibles are short and broad, with toothlike points grouped around a central concavity. The maxillary palpi extend little i f at all beyond the anterior edge of the labium. The mesonotum is lightly sclerotized, each primary plate bearing a dark, curved bar ( B ) . Length of larva up to 12 m m . C A S E To accommodate their stout-bodied architects, cases of Ceraclea are unusually wide anteriorly, tapered sharply and curved toward the rear. They are made of sand grains and usually have an overhanging dorsal l i p , which in some species is extended along both sides as a flange (C) as i n molannid cases. I n species associated with sponges, cases are made almost entirely of silk alone ( G ) , sometimes w i t h pieces of sponge incorporated (Resh 1976). Length of larval case up to 13 m m . B I O L O G Y Ceraclea larvae inhabit both lentic and lotie waters, and most species are restricted to rather narrow limits within this range (Resh and Unzicker 1975). Larvae are usually found on bottom substrates and many species are detritus feeders (Resh 1976); but larvae of a number of Ceraclea species feed on freshwater sponges (Lehmkuhl 1970; Resh 1976; Resh et al. 1976), and can be found burrowing i n sponge colonies.

Ceraclea spp. A - E (Saskatchewan, Lac La Ronge Pro v. Park, June 1959, R O M ) A, larva, lateral x l 5 , lateral hump sclerite enlarged; B , head and thorax, dorsal, long antenna enlarged; C, case, ventral x9, posterior opening i n lateral view to show dorsal position; D , head, lateral; E, head, ventral F, G (Minnesota, Clearwater Co., 17 A u g . 1972, R O M ) F, head, dorsal, short antenna enlarged; G, case of silk, ventral x5 252

Leptoceridae:

Ceraclea 19.1

253

19.2 Genus Leptocerus A N D S P E C I E S Leptocerus comprises species of Holarctic and Oriental distribution; a single species, L. americanus (Banks), is known in North America, recorded from Minnesota to Maine and south to Texas and Tennessee. Larval characters have been described by several workers: Vorhies (1909) and Lloyd (1921) as Setodes grandis; and by Ross (1944). D I S T R I B U T I O N

Leptocerus larvae are distinguished primarily by the structure of the apical segments of the middle legs ( A ) : the tibia and tarsus are thickened and bear ventral ly a row of teeth with stout setae; the tarsal claw is thickened and curved with two apical points. The hind legs are densely setate, furthering their effectiveness as swimming paddles. The ventral apotome of the head (D) is triangular but does not separate the genae posteriorly; the posterior ventral ecdysial line is weakly defined. The bases of the anal prolegs bear stout setae ( E ) . In living specimens, membranous parts of the body are bright green. Length of larva up to 7 mm. M O R P H O L O G Y

Larval cases are made entirely of tough silk, strongly tapered and slightly curved ( C ) . In contrast with most other case-making genera, Leptocerus larvae are highly dependent on their cases; in observations I have made on early instars, they do not crawl or swim when removed from their cases, and seem incapable of constructing new ones. Length of larval case up to 9.5 mm. C A S E

By rapid movements of their hind legs, larvae swim among aquatic plants growing in lentic waters. A net sample from surface beds of submersed aquatic plants such as Ceratophyllum, placed in a large container of water, will often yield astonishing numbers of larvae that otherwise would not be seen. The strangely modified middle leg, especially the hooked tarsal claw, probably enables the larva to hold a firm resting position on plants. Gut contents of larvae (3) were almost entirely fine particulate matter. B I O L O G Y

R E M A R K S

Larvae illustrated were provided by O.S. Flint.

Leptocerus americanus (New York, Tompkins Co., 15 July 1958, U S N M ) A , larva, lateral x20, portion of middle leg enlarged; B , head and thorax, dorsal; C , case, lateral x ! 3 ; D , head, ventral; E , anal prolegs, dorsal 254

Leptoceridae: Leptocerus

19.2

255

19.3 Genus Mystacides D I S T R I B U T I O N AND S P E C I E S Mystacides is mainly a Holarctic genus, w i t h some representatives in the Oriental region. Three species are currently recognized i n North America: M. interjecta (Banks) (treated i n many references as M. longicornis L . ) and M . sepulchralis (Walker), both northern and transcontinental; and M. alafimbriata H i l l - G r i f fin in western montane areas. Larval diagnoses for all three were given by Yamamoto and Wiggins (1964); subsequently larvae w i t h spotted heads similar to M. alafimbriata were found in a number of eastern localities, but adults associated with several of these series all proved to be M. sepulchralis. M O R P H O L O G Y Larvae of this genus are readily recognized by their head and thoracic markings o f strongly contrasting black spots or blotches on a light background. Mystacides larvae have a secondary division in both tibia and tarsus of the hind leg (A). The ventral apotome of the head is large and well defined i n the final instar ( E ) , and separates the genae completely, but is not clearly defined i n early instars. Mandibles are short, the toothed points grouped around a central concavity ( D ) . Single abdominal g i l l filaments are present i n M. interjecta, but gills are absent in the other two North American species. Two patches of spines occur on the venter of the anal proleg, the distal set rather long ( F ) . Length o f larva up to 10 m m . C A S E Larval cases in Mystacides are distinctive because of the twigs or conifer needles that usually extend well beyond the front end of a coarse-textured, straight tube (C) o f fragments of rocks, mollusc shell, or plant material. Length of larval case up to 30 m m . B I O L O G Y Larvae are usually found in the shallows along shores of lakes and ponds, or in areas of slow current of rivers. It is not uncommon for two of the species to occur together in the same habitat (Ross 1944; Yamamoto and Wiggins 1964); records suggest a single generation per year for all three species, w i t h emergence and flight period extending over much of the summer. Gut contents for M. sepulchralis were found by L l o y d (1921) to be fine particles of plant origin; we found high proportions of arthropod remains in larvae (3 o f each) o f both M. sepulchralis and M. inter]ecta. R E M A R K S Systematic data for the three North American species were summarized by Yamamoto and Wiggins (1964) and Yamamoto and Ross (1966). Conflicting interpretations of trans-Beringian relationships of Nearctic Mystacides were clarified by Wiggins and Parker ( i n press).

Mystacides sepulchralis (Manitoba, Duck Mountain Pro v. Park, 12 June 1962, R O M ) A, larva, lateral x l 6 , hind leg and lateral hump sclerite enlarged; B, head and thorax, dorsal; C, case, ventral x6; D , mandible and maxilla, ventral; E , head, ventral; F, anal proleg, ventral 256

Leptoceridae: Mystacides 19.3

257

19.4 Genus Nectopsyche DISTRIBUTION A N D SPECIES

A l l Nearctic species formerly treated underLeptocella

have been assigned to Nectopsyche

(Flint 1974c), a genus restricted to the N e w World.

Fifteen species have been described from this continent north o f M e x i c o , but some o f the names are o f uncertain status (Ross 1944; Haddock 1977). Under the name Leptocella

larvae were characterized for six species by Ross (1944),

and described in detail for N. albida (Walk.) (as L . uwarowii

Kolenati) by Vorhies (1909)

and Elkins (1936). M o r e recently, larvae and adults o f the N o r t h American species were reviewed by Haddock (1977). MORPHOLOGY

The ventral apotome is triangular ( E ) and the hind tibia is not second-

arily subdivided ( A ) . The mandibles and maxillary palpi are similar to those in (Fig.

19.3D). Other characters for Nectopsyche

Mystacides

include the sclerotized bar and circular

roughened area on each lateral hump o f abdominal segment I ( A ) and the unpigmented lines delimiting the anterolateral corners o f the pronotum ( B ) ; we have some specimens from Ontario i n which the anterolateral margin o f the pronotum is scalloped ( G ) . Head markings range from marbled blotches to discrete bands (Ross 1944, figs. 744-48), and the ends o f the leg segments are dark in some species; a small gill filament arises on the posterolateral corner o f the metanotum in some species; abdominal gills may be present ( A ) or absent. A ventral band of tiny spines lies on the basal segment o f each anal proleg adjacent to the anal opening i n at least some species ( F ) . Length o f larva up to 15 m m . CASE

Larval cases ( C ) are usually long and slender, and made of plant and mineral frag-

ments, w i t h twigs or conifer needles extending beyond one end; we have one pupal case from Ontario similar to the flattened cases o f the limnephilid genus Chyranda.

I n some

species, cases are almost entirely o f mineral materials (Ross 1944, f i g . 76), or o f diatoms (Wallace et al. 1976). Length o f larval case up to 31 m m . BIOLOGY

Nectopsyche

larvae inhabit lakes and slower currents o f rivers on the bottom

substrate or on plants. Larvae of at least some species can s w i m . Gut contents o f larvae (3) we examined were largely fine organic particles and vascular plant tissue; Elkins (1936) found a larva gorged w i t h ostracods. Observations on case recognition ( M e r r i l l 1969) indicate that larvae o f this genus are among the few that back into their cases, although not to the complete exclusion o f entry head first.

Nectopsyche

intervena

(Banks) (California, Inyo Co., 16 M a y 1969, R O M )

A , larva, lateral x l 1, lateral hump sclerite enlarged; B , head and thorax, dorsal; C, case, lateral x7; D , head, lateral; E, head, ventral; F, anal prolegs, ventral Nectopsyche 258

sp. (Ontario, A l g o m a D i s t , 5 Sept. 1959, R O M ) : G , pronotum, dorsal

Leptoceridae: Nectopsyche 19.4

259

19.5 Genus Oecetis D I S T R I B U T I O N AND S P E C I E S Oecetis is a large genus represented in all faunal regions of the w o r l d . I n North America approximately 20 species are known in Canada and the United States; as a group they are widely distributed and often abundant. Diagnostic characters for larvae of five species were given by Ross (1944). We have material from much of the continent. M O R P H O L O G Y Oecetis larvae are distinguished from all other North American leptocerids by the secondary setae on the labrum ( D ) , and by long maxillary palpi and singleblade mandibles ( B , E ) w i t h a sharp apical tooth separated by a gap from the other teeth ( E ) . We have evidence indicating some variation in the length o f the maxillary palpi in sub-terminal instars, or perhaps between species. The ventral apotome of the head is trapezoidal ( F ) , and does not separate the genae posteriorly; the median ecdysial line behind the ventral apotome is indefinite. Length of larva up to 12.5 m m . CASE

Larval cases o f Oecetis

species are varied in both form and material; some are

constructed of small fragments of rock (c), often combined w i t h bark or leaves, others o f short lengths o f stems and twigs placed transversely (Ross 1944, f i g . 833). Length of larval case up to 15 m m . B I O L O G Y Oecetis larvae are bottom dwellers, l i v i n g in both lentic and lotie waters; some Palaearctic species are reported from brackish water (Lepneva 1966). Early-instar larvae of at least some species can swim w i t h their cases, but we have not observed later instars doing so. The long mandibles identify Oecetis larvae as predators; gut contents o f larvae from a lake i n British Columbia showed that animals were the dominant food ( W i n terbourn 1971a). A n Asian species o f Oecetis is reported to feed on rice plants in Japan (see B a l d u f 1939).

Oecetis sp. (Manitoba, Duck Mountain Prov. Park, 12 June 1962, ROM) A, larva, lateral x l 5 ; B , head and thorax, dorsal; C, case, ventrolateral x l O ; D , labrum, dorsal; E , mandible and maxilla, ventral; F, head, ventral 260

Leptoceridae: Oecetis 19.5

261

19.6 Genus Setodes D I S T R I B U T I O N AND S P E C I E S

Eight North American species are now assigned to Set-

odes; records are confined to the eastern half of the continent, from Minnesota through Ontario, Q u é b e c , and Maine to Oklahoma and Louisiana. The genus is widely distributed through the world.

Larvae have been associated w i t h certainty only for S. incertus (Walk.) ( M e r r i l l and

Wiggins 1971); a second larva described there may be S. stehri (Ross) (Holzenthal 1982). MORPHOLOGY

Larvae are distinguished from other leptocerids by the sclerotized,

spiny anal plates ( G ) ; these plates are specializations of the lateral sclerite and the two patches of spines evident in other genera such as Triaenodes.

Colours of head and thorax

are pale ( B ) or dark ( M e r r i l l and Wiggins 1971, fig. 12). The ventral apotome of the head in final instars is rectangular and separates the genae completely ( F ) , but is not clearly defined i n early instars. The mandibles have tooth-like points around a central cavity ( E ) , and the maxillary palpi are short as in Mystacides

(Fig. 19.3D). The hind tibia is second-

arily subdivided ( D ) . Length of larva up to 8.5 m m . CASE

Larval cases ( C ) are constructed of rock fragments, slightly curved but w i t h little

taper. The posterior opening is of approximately the same diameter as the anterior opening, and is not restricted w i t h silk or rock. Length of larval case up to 8.5 m m . BIOLOGY

Setodes larvae occur in running waters and also along lake shores. Observa-

tions on l i v i n g larvae in captivity ( M e r r i l l and Wiggins 1971) indicate that the larvae burrow into loose sand to conceal all but the case opening at which the larva stations itself; larvae can reverse their position within the case, which is correlated w i t h the observation that there is essentially no difference between anterior and posterior ends. The armoured posterior end of the larva may then be a protective adaptation for repelling intruders from what w o u l d otherwise be an exposed rear flank, thus compensating for the specialized case-building behaviour. Larval guts contained fine particles, vascular plant fragments, and arthropod sclerites; i n captivity larvae fed readily on enchytraeid worms. W h i l e feeding, larvae were observed to reverse their respiratory current, a useful arrangement for burrowing larvae, perhaps enabling them to flush faeces from the case. These and other aspects of the biology o f Setodes were considered by M e r r i l l and Wiggins (1971). REMARKS

Taxonomy and distribution of the North American species have been sum-

marized by Holzenthal (1982).

Setodes incertus (Michigan, Presque Isle Co., 1 July 1969, R O M ) A , larva, lateral x 2 1 , lateral hump sclerite enlarged; B , head and thorax, dorsal; C, case, lateral x l 4 ; D , hind leg, lateral; E, mandibles, dorsal; F, head, ventral; G , anal prolegs, caudolateral, anal claw enlarged 262

Leptoceridae: Setodes 19.6

263

19.7

Genus

Triaenodes

D I S T R I B U T I O N AND S P E C I E S The genus Triaenodes is predominantly Holarctic but extends also into the Ethiopian and Oriental faunal regions, and into the northernmost part of the Neotropical region (Flint 1967a). The group is widely distributed over North America, and 23 species are now known north o f M e x i c o ; most occur in the eastern half of the continent but some are transcontinental. Larval diagnoses and a key were provided for 19 species by Glover (1993). A key to larvae o f five species was given by Ross (1944); larval characters for T.flavescens Banks were provided by Vorhies (1909), and for T marginatus Sibley by Sibley (1926). M O R P H O L O G Y Head markings are usually dark bands or blotches contrasting with a light ground colour (B). Most Triaenodes larvae have a dense fringe of long setae on the hind tibia and tarsus (A), presumably an asset for swimming. However, in larvae of T. taenius (Ross) this dense setal fringe is reduced (Manuel and Braatz 1984), as it is in some other species (Glover 1993); but even when reduced, the setal fringe in Triaenodes larvae is denser than in similar genera such as Mystacides. I n young larvae of Triaenodes and Ylodes the ventral apotome is triangular, the rectangular condition (D) developing in later instars. Length of larva up to 14.5 m m . C A S E Slender, tapered cases of plant pieces arranged in a spiral (C) are constructed by larvae o f Triaenodes. Depending on the habitat, the cases are constructed of pieces o f leaves (C), often including green leaf tissue, or of short lengths of plant roots, when they are uniformly light in colour. Cases o f either dextral or sinistral spirals occur ( M e r r i l l 1969), and this behaviour pattern is fixed for one or the other in an individual larva (Tindall 1960). Length of larval case up to 33 m m . B I O L O G Y Larvae of most Triaenodes occur in plant beds in both standing and moving waters where they s w i m w i t h their cases, propelled by rapid movements o f the hind legs. L i v i n g plant tissues are ingested (Berg 1949; McGaha 1952; Tindall 1960). Triaenodes larvae exploit green plants so successfully that at least one species, T. bicolor (Curtis), has become a pest of cultivated rice in Italy (Moretti 1942); this is also testimony to the high water temperatures o f 28 to 3 1 ° C that can be tolerated. Larvae of some species, such as T. taenius, live i n small cool streams among submerged root mats o f riparian plants (Manuel and Braatz 1984; Glover 1993); they construct cases of root pieces, have a reduced setal fringe on the hind legs, and do not swim. R E M A R K S Distinction between larvae o f Triaenodes and Ylodes (q.v.) is uncertain. Triaenodella Mosely has been treated as both a genus and as a subgenus of Triaenodes (cf. Morse 1981; Yang and Morse 1993); no information on the larval stage has been advanced in support of generic status (cf. Lepidostoma, pp. 241-2).

Triaenodes sp. (Ontario, Kent Co., 3 June 1965, ROM) A, larva, lateral x l 4 , hind tibia and lateral hump sclerite enlarged; B, head and thorax, dorsal; C, case, lateral x7; D, head, ventral; E, anal prolegs, ventral 264

Leptoceridae: Triaenodes

19.7

265

19.8 Genus Ylodes D I S T R I B U T I O N AND S P E C I E S Species of this genus occur i n western and north central North America, through northern Asia and Europe (Manuel and N i m m o 1984). Four North American species are known: Y frontalis (Banks), Y. schmidi Manuel & N i m m o , Y kaszabi Schmid, and Y reuteri (McLachlan) (= Triaenodes griseus Banks); the latter two species are Holarctic. Since K kaszabi and schmidi are known in North America only from Alaska and Yukon, material o f Ylodes from other parts of the continent is likely to be either Y frontalis or reuteri, both of which range from Manitoba westward and south to Colorado. We have material for a larval association o f Y reuteri established through rearing by G.G.E. Scudder; and we have several series of similar larvae taken at sites where Ylodes adults occur, most of which were studied by Glover (1993) in proposing diagnoses for four North American species. M O R P H O L O G Y Characters proposed as diagnostic for Ylodes by Manuel and N i m m o (1984), including the presence of a g i l l in the posterolateral position of segment III (A), have proved to be variable through our analyses and those of Glover (1993). Characters of leg setation used to separate Ylodes from Triaenodes in Europe ( I . D . Wallace et al. 1990) proved to be variable i n North American species (Glover 1993). From circumstantial larval associations for Ylodes species, Glover (1993) proposed that larvae of this genus could be distinguished by a thin crescent of the light ground colour along the posterior margin of the head (B). Although this diagnosis was equivocal for at least one North American species, it appeared to hold for others and for several Eurasian species described in the literature (Glover 1993). Markings on the head are usually dark brown spots at muscle scars (B). Length o f larva up to 12 m m . C A S E Slender cases of pieces of leaves or o f roots fastened together in a continuous spiral are characteristic of Ylodes (C), as they are of Triaenodes. Both dextral and sinistral spirals occur i n each genus. I t is unknown whether all Ylodes larvae swim with their cases; some have the same dense long setae on the hind legs as do Triaenodes larvae that swim, and some do not. Length o f larval case up to 22 m m . B I O L O G Y Larvae o f Ylodes occur in the same types of habitats as Triaenodes do aquatic plant beds in lentic waters and the submerged root mats o f riparian plants i n small streams. Ecological data on Y frontalis were published by Richardson and Clifford (1986).

Ylodes (prob. reuteri McLachlan) (British Columbia, Chilcotin, June 1966, ROM) A, larva, lateral x l l , lateral hump sclerite enlarged; B, head and thorax, dorsal; C, case, lateral x6; D, anal prolegs ventral 266

Leptoceridae: Ylodes 19.8

267

20 Family Limnephilidae

The Limnephilidae are the largest family o f Trichoptera in North America, w i t h some 230 species now assigned to 39 genera. The group is dominant at higher latitudes and elevations through much o f the northern hemisphere. Larvae o f Limnephilidae occupy a wider range of habitats than any other family in the Trichoptera, reflected in the fact that about one-quarter o f all Nearctic caddisfly genera are members of this single family. There are genera characteristic o f spring streams, o f rivers, of lakes, and o f marshes; there are some whose larvae live in temporary pools and streams, and a few limnephilid larvae live in moist terrestrial sites. Plant materials are the principal food. Larvae in the subfamilies Pseudostenophylacinae and Limnephilinae are shredders, reducing larger pieces of plant debris to small particles, although the fungi growing on the dead plant materials are the primary source o f nutrients (Mackay and Kalff 1973). L i m nephilid larvae occasionally found clustered on the body o f dead fish (Brusven and Scoggan 1969) or mammals may be attracted to the microorganisms associated with the decomposition of these tissues. Larvae in some genera o f the Dicosmoecinae feed mainly by scraping periphyton and fine organic particles from rock surfaces. Diapause is known in the life cycle of a number o f species in the Limnephilidae; development is suspended for a time and reactivated, largely by changing photoperiod, w i t h the result that the life cycle coincides more effectively w i t h seasonal changes and food resources i n particular habitats (see General Section under Life Cycles). Larvae in some limnephilid genera construct cases o f rock fragments, and in others plant materials are used. In the Nearctic fauna, at least, these behavioural patterns bear a broad relationship to the subfamilial groupings, as indicated in the outline of characters that follows. In general, larvae living in currents of cool waters use rock materials for case-building, and those in more lentic habitats, especially in warmer waters, use plant materials. Larval diagnosis for the family as a whole is based on a combination o f several characters: consistent location o f the antenna approximately midway between the eye and the anterior edge of the head capsule, with a prosternai horn and chloride epithelia almost always present. Extensive development o f setae on abdominal segment I in many 268

20 F a m i l y Limnephilidae Limnephilidae is unusual among Nearctic caddisfly families. Arrangement o f these setae has proved to be o f particular taxonomic value in working out diagnostic characters for the genera; and it is possible that the chaetotaxy o f segment I w i l l prove to be useful for recognizing larvae to species. A descriptive basis for these setae is outlined in the General Section under Morphology. As in other families o f the Limnephiloidea, forked lamellae and bifid filaments occur on the lateral line o f the abdomen i n most genera, but not i n all. A l l o f the traditional elements o f the Limnephilidae were resolved into a single comprehensive classification o f the world fauna in a landmark study by Schmid (1955). Although based almost entirely on characters of the adults, that classification was shown to have a considerable level of concordance with larval morphology (Flint 1960). Further study, especially of the western Nearctic fauna, demonstrated that there were, however, some lineages still discordant w i t h the subfamilial groupings o f the classification ( W i g gins 1973c). Phylogenetic analysis of the subfamily Neophylacinae and several genera allied to Neothremma led to their transfer from the Limnephilidae to the Uenoidae (q.v.) (Wiggins et al. 1985; Vineyard and Wiggins 1988). Phylogenetic analysis of the L i m nephiloidea led to erection of the families Apataniidae and Rossianidae (q.v.), and re-definition o f the Goeridae (q.v.) (Gall and Wiggins, i n press); through these modifications the long-standing problem of the Limnephilidae genera incertae sedis (Wiggins 1973c, 1977) was resolved. Because the Limnephilidae are such a large group, it is useful to consider character states for each subfamily. Thus, in what follows, the general comparative features o f larvae i n each subfamily of the Limnephilidae are given, although these are not necessarily diagnostic. Only one subfamily, the Drusinae (Ecclisopteryginae o f Nielsen 1943b), is not represented in North America; species o f this group, largely European, occur i n cold, running waters. D I C O S M O E C I N A E : Aliocosmoecus, Amphicosmoecus, Cryptochia, Dicosmoecus, Ecclisocosmoecus, Ecclisomyia, Eocosmoecus, Ironoquia, Onocosmoecus Head with primary setae only; mandibles usually but not always w i t h separate tooth-like points; labrum w i t h anterolateral margins entirely sclerotized; labium w i t h sclerite o f palpiger ring-like, extending more than half-way around base o f labial palp; maxilla w i t h lobe sclerotized, elongate, and finger-like (shorter i n Cryptochia); ventral apotome vase-shaped. Thorax not modified; primary setal areas o f mesonotum tend to be confluent; metanotal sal and sal represented by pair of sclerites bearing setae (sal sclerites fused in Amphicosmoecus); trochanteral brush present on all legs; femora o f middle and hind legs w i t h three or more major setae on ventral edge. Abdominal gills single or multiple; lateral fringe of bifid filaments present; chloride epithelia ventral only; dorsal sclerite o f segment I X w i t h many setae; anal claw w i t h accessory hook. Cases constructed of rock materials i n some genera, of plant materials i n others. Represented over most o f the Holarctic region, the Dicosmoecinae are the only group of the Limnephilidae to occur i n the southern hemisphere as well. Except for some species of Ironoquia that live in temporary pools and streams, North American larvae o f this subfamily are characteristic o f permanent, cool, usually running, waters. This subfamily is believed to contain the most primitive l i v i n g members o f the Limnephilidae. 269

20 Family Limnephilidae L I M N E P H I L I N A E Characters generally as in the Dicosmoecinae, except that mesonotal setae are reduced in number and primary setal areas tend to be separate; middle and hind femora usually have only two major setae on ventral edge; and setae on dorsal sclerite o f segment IX usually are reduced in number. Cases in most genera are constructed o f plant materials, although rock materials are used in some. This is the dominant group of the Limnephilidae, comprising approximately one-half of all species in the family. Four tribes are recognized, and all but the Chaetopterygini, a small Palaearctic group, are represented i n North America. Chilostigmini: Chilostigma, Chilostigmodes (larva unknown), Frenesia, Glyphopsyche, Grensia, Homophylax, Phanocelia, Psychoglypha Abdominal gills single i n some genera, branched in others; chloride epithelia occur ventrally only. Lateral sclerite of anal proleg w i t h several very stout, short setae. Genera are characteristic o f both cool lotie and warm lentic waters. L i m n e p h i l i n i : Anabolia, Arctopora, Asynarchus, Clistoronia, Grammotaulius, Halesochila, Hesperophylax, Lenarchus, Leptophylax (larva unknown), Limnephilus, Nemotaulius, Philarctus, Platycentropus, Psychoronia, Sphagnophylax Most abdominal gills of dorsal and ventral series arise i n clusters of three or more filaments; chloride epithelia frequently occur on side and dorsum of abdominal segments as well as venter. Larvae of most genera use plant materials for cases, but rock materials are used by some. This tribe includes most of the lentic genera o f the Limnephilidae, a fact correlated generally w i t h the occurrence o f multiple g i l l filaments throughout the group (Wichard 1974). Stenophylacini: Chyranda, Clostoeca, Desmona, Hydatophylax, Philocasca, Pycnopsyche A b d o m i n a l gills single; chloride epithelia present only on venter o f abdominal segments. Most species i n this tribe live i n cool, lotie waters. P S E U D O S T E N O P H Y L A C I N A E : Pseudostenophylax Characters generally as in Dicosmoecinae, except abdominal gills single and setae present on membrane between metanotal sal sclerites. Case o f sand grains. This group is predominantly one of the Oriental and Asian Palaearctic regions, w i t h only a small Nearctic element (Schmid 1955, f i g . 7). Larvae of the sole North American genus live i n small cool streams. A satisfactory generic key to limnephilid larvae is difficult to produce and often tedious to use. The key that follows is based on close comparative study of a great deal of material. Consistent diagnosis for many genera was found possible only w i t h characters requiring careful microscopic study under good illumination. Final instars should always be used where possible because setae and small sclerites may not be fully developed in younger larvae. It is especially important in the Limnephilidae to confirm each generic identification w i t h the corresponding summary of structural, biological, and distributional information. Since a large number of species are not yet k n o w n in the larval stage, some specimens may not be identifiable w i t h the key in its present form.

270

20 F a m i l y L i m n e p h i l i d a e Key to G e n e r a 1

1 2

Anterior margin o f pronotum densely fringed with long setae (Fig. 20.10A); dorsum o f head flattened and bearing two bands o f closely packed scale-setae (Fig. 20.10B); case o f wood and bark fragments arranged transversely, flattened dorsoventrally and tapered (Fig. 20.10c). Western 20.10 Cryptochia Anterior margin o f pronotum and dorsum o f head without dense setae as above

2

(Fig. 20.2B) 2

3

(1) Abdominal gills of single filaments (Fig. 20.9A)

Most abdominal gills o f dorsal and ventral rows with branched filaments (Figs. 20.21A, 20.26A), lateral gills sometimes single (Fig. 20.17A) 17 3

(2) Metanotal sal and sal sclerites large in relation to metanotum, distance between sal sclerites approximately 2 to 3 times the maximum dimension o f one sal sclerite (Fig. 20.14B); case a slender tube o f rock fragments, frequently incorporating long pieces o f plant material (Fig. 20.14c). Western 20.14 Ecclisomyia Metanotal sal and sal sclerites smaller than above in relation to metanotum, distance between sal sclerites more than twice the maximum dimension of one sal sclerite (Fig. 20.7B); sal sclerites sometimes fused into single median scler-

4

ite (Fig. 20.23B) 4

(3) Each mesonotal plate distinctly wider than long, and shorter mesally than laterally (Fig. 20.29B); abdominal segment V I I I with transverse posterodorsal line o f slender, closely spaced setae (Fig. 20.29E); cases of pieces o f moss arranged transversely (Fig. 20.29c). Widespread, local 20.29 Phanocelia Mesonotal plates o f varying width, but length differing little from lateral margin to median line (Figs. 20.6B, 20.7B); abdominal segment V I I I with or without posterodorsal line o f setae, but less dense than above i f present (e.g. Fig. 20.1 I D ) 5

5

(4) Lateral humps o f segment I w i t h one or two sclerites adjacent to base o f hump, the sclerites often only lightly pigmented but distinguished by the smooth and relatively shinier surface (Figs. 20.7A, 20.22A, 20.34A, 20.36A) 6 Lateral humps of segment I without sclerites (Fig. 20.13A)

6

12

(5) Large single sclerite at base o f lateral hump enclosing posterior half of hump

1 See qualifications under Use of Keys, p. 7 2 Larvae are unknown in two genera: Chilostigmodes, recorded from Alaska to Labrador (see Krivda 1961); Leptophylax, recorded from north-central states (see Ross 1944). 271

20

Family L i m n e p h i l i d a e and extending posterodorsad as irregular lobe (Fig. 20.7A); case o f leaves or bark formed into flattened tube w i t h lateral seam and narrow flange along each side (Fig. 20.7c). Transcontinental

20.7 C h y r a n d a

One or two smaller sclerites at base of lateral hump (Figs. 20.11 A , 20.22A, 7

20.34A, 20.36A) 7

(6) One elongate sclerite at posterior edge o f base o f each lateral hump (Fig. 8

20.23A) Two or more sclerites, variously shaped and positioned, at base of each lateral

10

hump (Figs. 20.11A, 20.34A) 8

(7) Sclerite at base o f lateral hump elongate, its longest dimension almost equiva9

lent to basal width o f hump (Figs. 20.23A, 20.36A)

Sclerite at base o f lateral hump shorter, its longest dimension equal to approximately one-half the basal width o f hump (Fig. 20.22A); case usually a cylinder of smooth outline and thin walls, rarely three-sided, consisting largely o f bark pieces irregularly arranged (Fig. 20.22c), occasionally o f rock pieces. Western 20.22 Homophylax 9

(8) Metanotal sal sclerites fused on mid-dorsal line into single sclerite (Fig. 20.23B, D ) ; segment I I with ventral chloride epithelium, and segment I X w i t h only a single seta laterad o f dorsal sclerite (77. argus); or venter 11 without chloride epithelium, and segment I X w i t h tuft o f 3-6 setae laterad of dorsal sclerite (H. hesperus, F i g . 20.23A); case o f wood pieces or leaves, irregular in outline (Fig. 20.23c). Eastern and western

20.23 Hydatophylax

Metanotal sal sclerites not fused on mid-dorsal line (Fig. 20.36B) although often close together; venter I I without chloride epithelium, segment I X usually w i t h single seta laterad of dorsal sclerite (Fig. 20.36A); case of twigs or gravel, or o f leaves and occasionally three-sided (Fig. 20.36c). Widespread i n east, extending to Rocky Mountains 10

20.36 Pycnopsyche

(7) Two small, ring-shaped sclerites located posterodorsally at base o f each lateral hump (Fig. 20.11A); case largely of rock fragments w i t h some small pieces o f wood (Fig. 20.11c). Western

20.11

Desmona

Two or more sclerites dissimilar in shape at base o f each lateral hump (Figs. 11

20.9E, 20.34A) 11

(10) One or t w o small rounded posterior sclerites and one elongate dorsal sclerite at base o f each lateral hump (Fig. 20.34A), or dorsal area o f small discrete sclerites at bases o f setae; case a straight tube o f rock and wood fragments (Fig. 20.34c). Transcontinental

20.34 Psychoglypha

One irregular posterior sclerite and an irregular dorsal sclerotized area surrounding the bases o f 2-3 setae (Fig. 20.9E) 272

14

20 12

Family

Limnephilîdae

(5) Anterior margin of pronotum with flattened scale-setae, dorsum of head flattened (Fig. 20.31B, D ) ; cases of coarse rock fragments, slightly curved (Fig. 20.31c). Western 20.31 Philocasca Anterior margin of pronotum with normal setae only, dorsum o f head usually convex, rarely flattened (only in the western species Pseudostenophylax edwardsi, Fig. 20.33D) 13

13

(12)

Mesonotal sal and sal separated by gap free of setae (Fig. 20.9B)

14

Mesonotal sa 1 and sal connected by continuous band of setae (Fig. 20.13B) 16 14(11,13) Pronotum covered w i t h fine spines (Fig. 20.19B); cases of plant and rock fragments (Fig. 20.19C). Arctic 20.19 Grensia Pronotum smooth, lacking fine spines (Fig. 20.9B) 15

15

(14) Each mesonotal plate w i t h length and width approximately equal (Fig. 20.9B); cases of leaf pieces fastened together to form flanges at each side of flattened tube (Fig. 20.9c). Western 20.9 Clostoeca Each mesonotal plate clearly wider than long (Fig. 20.6B); case a rough cylinder of leaf and bark fragments arranged irregularly (Fig. 20.6c). K n o w n only from Minnesota 20.6 Chilostigma

16

(13)

Head and pronotum strongly inflated and with pebbled texture (Fig. 20.13A, B ) ; case of small rock fragments, tapered and curved, outline smooth (Fig. 20.13c). Western 20.13 Ecelisocosmoecus Head and pronotum not unusually inflated (Fig. 20.33A, B), although dorsum of head flat in the one western species (Fig. 20.33D); sclerotized areas not pebbled; case of rock fragments, tapered and curved, outline smooth (Fig. 20.33c). Eastern and western 20.33 Pseudostenophylax

17

18

(2)

Most gills with two or three branches (Fig. 20.26A), none with more than four

(Fig. 20.12A)

18

A t least some gills w i t h more than four branches (Figs. 20.21A, 20.25A, 20.35A)

39

(17) Dorsum of head w i t h two contrasting dark bands extended from coronal suture to base of each mandible (Fig. 20.20B), and/or narrowed posterior portion o f frontoclypeus with three light areas - one at posterior extremity and usually one along each side (Figs. 20.8B, 20.26B) 19 Dorsum o f head lacking bands or other well-defined contrasting areas, usually largely uniform in colour (Fig. 20.1B), often with prominent spots (Fig. 20.3B)

25 273

20 Family Limnephilidae 19

(18) Dorsum of head with prominent dark bands contrasted against a light background, lateral bands extended from coronal suture to base of each mandible, median band on frontoclypeus (Figs. 20.20B, 20.27B) 20 Dorsum of head lacking dark lateral bands, but narrowed posterior portion of frontoclypeus with three light areas - one along each side and one at the apex (Figs. 20.5B, 20.8C) 22

20

(19) Dark dorsal bands on head fused at junction of coronal and frontoclypeal sutures to form U-shaped marking, pronotum with narrow dark bands along anterior border and across dorsum (Fig. 20.27B); case usually of leaf pieces arranged transversely on dorsal and ventral surfaces (Fig. 20.27c), sometimes only longitudinally in final instar. Transcontinental 20.27 Nemotaulius Dark, dorsal bands on head extended posterad beyond junction of coronal and frontoclypeal sutures to form V-shaped marking (Fig. 20.20B); pronotal markings variable 21

21

(20) Chloride epithelia present dorsally on abdominal segments, as well as ventrally and laterally (Fig. 20.20A); case of wood or leaf fragments (Fig. 20.20c), changed to fine gravel during final instar. Western 20.20 Halesochila Chloride epithelia lacking dorsally, present only ventrally and sometimes laterally (Fig. 20.26A) 24

22

(19) Venter I usually with more than 100 setae merged from all setal areas (Fig. 20.8D); small spines on head and pronotum (Fig. 20.8B); short, stout setae on lateral sclerite of anal proleg (Fig. 20.8A); case cylindrical, usually of pieces of twigs and bark, sometimes of small rock fragments (Fig. 20.8c). Western 20.8 Clistoronia Venter I with fewer than 100 setae overall and primary setal areas discrete, usually without spines on head and pronotum; short, stout setae on lateral sclerite of anal proleg usually lacking; cases highly variable (e.g. Fig. 20.26) 23

23

(22) Chloride epithelia present both dorsally and ventrally on most abdominal segments (Fig. 20.5A); case of plant and rock materials (Fig. 20.5c). Northern, extending south in western mountains 20.5 Asynarchus (in part) Chloride epithelia lacking dorsally, but present ventrally and occasionally laterally (Fig. 20.26A) 24

24(21,23) Mesothoracic femur with the two major ventral setae situated at either side of and equidistant from midpoint of femur (Fig. 20.26A); cases of a wide range of materials and architecture (e.g. Fig. 20.26C-F). Widely distributed throughout the continent 20.26 Limnephilus (in part) Mesothoracic femur with the two major setae not equidistant from midpoint, 274

20 F a m i l y L i m n e p h i l i d a e but w i t h proximal seta about midway between proximal end of femur and distal seta (Fig. 20.30A); case o f fine gravel, sedge seeds, or snail shells (Fig. 20.30c). Western 20.30 Philaretus 25

(18)

Femur o f hind leg with two major setae arising from ventral edge, setae may be unequal (Fig. 20.17A)

26

Femur o f hind leg with more than two major setae arising from ventral edge (Fig. 20.12A) 35 26

(25)

Pronotum and lateral sclerite o f anal proleg bearing sharp, stout, spine-like setae (Fig. 20.17A, B )

27

Pronotum without sharp, stout setae (Fig. 20.3B), lateral sclerite of anal proleg never w i t h setae as above 28 27

(26)

Tibiae and tarsi of all legs w i t h dark, contrasting band (Fig. 20. 17A); case of twigs and bark arranged to form smooth cylinder (Fig. 20.17c). Transcontinental 20.17 Glyphopsyche Tibiae and tarsi lacking dark band (Fig. 20. 16A); case mostly o f small stones with wood fragments forming smooth cylinder (Fig. 20.16c). Eastern 20.16 Frenesia

28

(26)

Chloride epithelia present dorsally on at least some abdominal segments (Fig. 20.5A) 29 Chloride epithelia lacking dorsally on abdominal segments (Fig. 20.26A)

29

(28)

Metanotal sal represented by a few setae, usually two, without sclerite (Fig. 20.4B); case o f elongate leaf pieces arranged in smooth cylinder (Fig. 20.4c). Northern and western 20.4 Arctopora Metanotal sal with sclerite and more than two setae (Fig. 20.37B)

30

(29)

32

30

Dorsum of head w i t h numerous large spots often coalescing i n places into diffuse blotches, or small discrete spots, especially on frontoclypeal apotome (Fig. 20.3B). 31 Dorsum of head w i t h varied markings, but not spots as above (Fig. 20.5B); case o f plant and rock materials (Fig. 20.5c). Northern, extended south i n western mountains 20.5 Asynarchus (in part)

31

(30)

Anterolateral corner of pronotum w i t h small patch o f spines (Fig. 20.3D); case of plant materials, usually cylindrical (Fig. 20.3c) but sometimes three-sided. Transcontinental 20.3 Anabolia Anterolateral corner of pronotum lacking patch o f spines

34 275

20 Family L i m n e p h i l i d a e 32

(28)

Prosternai horn unusually long, extended ventral 1 y well beyond distal edge o f head capsule, approximately to men tu m o f labium (Fig. 20.32D); case cylindrical, o f short, narrow pieces o f plant material arranged transversely (Fig. 20.32c). Eastern and northern 20.32 Platycentropus Prosternai horn not unusually long, extended ventrally approximately to distal edge o f head capsule (Fig. 20.26A); cases diverse, o f plant or rock materials (Fig. 20.26C-F) 33

33

(32)

Chloride epithelia only on ventral surface o f abdominal segments (Fig. 20.37A); mesonotal sal with a single seta (Fig. 20.37B); venter o f abdominal segment I w i t h a single seta at sal (Fig. 20.37E); case mainly of leaf pieces arranged lengthwise. K n o w n only from arctic tundra o f Yukon and Northwest Territories 20.37 Sphagnophylax Chloride epithelia on ventral and occasionally on lateral surfaces o f abdominal segments (Fig. 20.26A); mesonotal sal usually with more than one seta (Fig. 20.26B); venter of abdominal segment I usually w i t h several setae at the sal position (Fig. 20.18E) 34

34(31,33) Dorsum o f head light brownish yellow with numerous discrete, small dark spots (Fig. 20.18B); case o f sedge or similar leaves arranged longitudinally to form cylinder (Fig. 20.18c). Northern and transcontinental 20.18 Grammotaulius Dorsum o f head with varied markings, usually darker than above; case o f wide range of materials (Fig. 20.26C-F). Widely distributed throughout continent 20.26 Limnephilus (in part) 35

36

(25)

(35)

Tibiae w i t h several pairs of stout spur-like setae (Fig. 20.1 A )

36

Tibiae w i t h only one pair o f stout spur-like setae, situated at the apex (Fig. 20.28A)

37

Dorsum I w i t h transverse row of setae posterior to median dorsal hump (Fig. 20. I D ) ; scale-hairs on dorsum o f head (Fig. 2 0 . I B ) ; venter I I with two chloride epithelia (Fig. 2 0 . I E ) ; case o f small pebbles arranged into slightly curved and flattened cylinder o f irregular outline (Fig. 20. l c ) . Western 20.1 Aliocosmoecus Dorsum I usually lacking setae posterior to median dorsal hump (Fig. 20.1 2D); scale-hairs absent from dorsum o f head; venter I I with single chloride epithel i u m (Fig. 20.12E) sometimes w i t h smaller epithelium at each side, or epithelia lacking on n; case o f final instar constructed o f small rock pieces (Fig. 20.12c), slightly depressed, w i t h plant materials in cases o f younger larvae. Western montane areas 20.12 Dicosmoecus

37 276

(35)

Metanotal sal sclerites usually fused along mid-dorsal line into single sclerite

20

Family L i m n e p h i l i d a e

(Fig. 20.2B), occasionally separated by a small gap; case a hollow t w i g w i t h ring o f bark pieces at anterior end (Fig. 20.2c), or entire case of wood fragments. Western, but extended to Saskatchewan 20.2 Amphicosmoecus Metanotal sa 1 sclerites always clearly separate (Fig. 20.15D, 20.28B) 38

(37)

38

Pronotum w i t h erect setae just behind anterior margin longest mesally, decreasing in length laterally, and widely spaced especially mesally (Fig. 20.15D); abdominal segment v u with single long posterodorsal seta on either side o f midline, sometimes w i t h 1 or 2 much smaller setae (Fig. 20.15c); lateral abdominal gills usually lacking from segment v, sometimes from IV or terminating at anterior position on IV (Fig. 20.15A); case of wood or rock pieces (Fig. 20.15B, E ) . Western 20.15 Eocosmoecus Erect setae just behind anterior margin of pronotum mostly of similar length, but w i t h seta on each side o f midline shorter and spaced closer to next lateral seta than intervals between remaining setae (Fig. 20.28B); abdominal segment v u w i t h 1-5 posterodorsal setae on either side of midline (Fig. 20.28D); lateral abdominal gills terminating at anterior position on segment V (Fig. 20.28A); case a rough cylinder of thin bark fragments (Fig. 20.28c). Transcontinental 20.28

39

Onocosmoecus

(17) Femora of second and third legs with 3 to 5 major setae along ventral edge (Fig. 20.24A); case of bark and leaves (Fig. 20.24c) or of sand. Eastern 20.24 Ironoquia Femora o f second and usually third legs w i t h two major setae along ventral edge (Fig. 20.21 A )

40

(39)

40

Metanotum with all setae confined to primary sclerites (Fig. 20.25B); case of lengths o f sedge leaves arranged longitudinally to form cylinder (Fig. 20.25c), or of fragments of bark and leaves. Northern and transcontinental, higher elevations i n western mountains from Alaska to California 20.25 Lenarchus Metanotum with at least a few setae arising between primary sclerites (Figs. 20.21B, 20.35B) 41

41

(40)

Lateral abdominal gills only on segment II and occasionally III, and of single f i l aments only (Fig. 20.35A); case of small rock fragments (Fig. 20.35c). H i g h elevations in New Mexico, Colorado, and probably adjacent states 20.35 Psychoronia Lateral series of abdominal gills usually extending to segment V, in some species only to III or IV, but at least some gills branched (Fig. 20.21A); case mostly of small rock fragments, sometimes w i t h wood pieces as well (Fig. 20.21c). Widespread 20.21 Hesperophylax

277

20.1

Genus A l l o c o s m o e c u s

D I S T R I B U T I O N AND S P E C I E S Allocosmoecus partitus Banks, the single species o f this genus, was known only from Idaho (Flint 1966); we have collected it in British Columbia, California, Idaho, Oregon, and Washington. The larva o f Allocosmoecus

was identified from specimens associated in California and

Oregon (Wiggins 1977). M O R P H O L O G Y Larvae are similar to those o f Dicosmoecus but are distinguished by short scale-hairs scattered over the head and pronotum ( B ) , and by a transverse row o f setae posterior to the median dorsal hump on abdominal segment I ( D ) . Allocosmoecus is also distinctive in having three ventral chloride epithelia on each of segments n i - V ( A , E ) , and in lacking forked lamellae on the side of abdominal segments. The femur of at least the hind legs bears more than two major setae ( A ) , and as i n Dicosmoecus, the middle and hind tibiae bear several pairs of stout, spur-like setae ( A ) . Sclerotized parts of the head and thorax are dark brown to black. For the most part, abdominal gills have three or four branches, occasionally one or two ( A ) . Length of larva up to 25 m m . CASE

Cases of final-instar larvae are constructed entirely of small stones but, as in

Dicosmoecus,

cases of the earlier instars show a transition from plant to rock materials.

Superficially the final-instar case is similar to that of Dicosmoecus

spp., but usually is

constructed of coarser pieces, giving it a rougher, cruder aspect. Length of larval case up to 31 m m . B I O L O G Y We collected larvae o f A. partitus in small, cool streams, but did not find them i n the larger rivers frequented by some species of Dicosmoecus. Gut contents of larvae (3) examined were mostly vascular plant fragments, fine organic particles, and filamentous algae. Our collections indicate that a generation is completed i n one year; larvae seal up their cases in June and July, and adults appear i n September and October, the length o f the intervening period suggesting that the larvae undergo diapause similar to Dicosmoecus (q.v.).

Allocosmoecus partitus (Idaho, Kootenai Co., 8 June 1967, ROM) A, larva, lateral x6, middle tibia enlarged; B , head and thorax, dorsal, portion of head capsule enlarged; C, case, ventral x4; D , segment I dorsal; E, segments I—III, ventral 278

Limnephilidae: AHocosmoecus 20.1

279

20.2 Genus

Aniphieosmoecus

D I S T R I B U T I O N AND S P E C I E S A single species, Aniphieosmoecus canax (Ross), is known in this genus. Originally discovered in Utah (Ross 1947), this species has been subsequently recorded from Alberta and British Columbia ( N i m m o 1965). The larva of A. canax was identified through material reared from British Columbia (Wiggins 1977); we have collected series of similar larvae i n Alberta, British Columbia, California, Oregon, and Saskatchewan. M O R P H O L O G Y Structurally, these larvae resemble Onocosmoecus, but can be distinguished by the fused sa 1 sclerites on the metanotum (B). Fusion of the sal sclerites may be incomplete i n some specimens but they are always very close together; mesal portions of the sclerites lack the brown pigment of the lateral portion and must be examined under good illumination to distinguish the sclerotized area. Sclerotized parts o f the head and thorax are golden brown i n colour and have the light dorsomedian band characteristic of several genera in the Dicosmoecinae; the hind femur bears more than two major setae, and the middle and hind tibiae bear only apical spurs (A). Length of larva up to 23 m m . C A S E Larvae believed to be of this genus have been found in cases that are of two types. One (C) is a hollow t w i g or stem, frequently w i t h a turret of bark pieces around the anterior end; in some cases the t w i g shows evidence o f having been tapered at the ends as illustrated, presumably by the mandibles. The other case type is constructed entirely o f small bits of wood suggestive of the case in Onocosmoecus, except that in Aniphieosmoecus the pieces are thicker. Length o f larval case up to 33 m m . B I O L O G Y These larvae live in small, cool streams although we have collected some in lakes in Saskatchewan. Our records are consistent with one generation per year; finalinstar larvae occur as early as June and July, adults in September and October. Evidence suggests that the species is local i n distribution, and even where it does occur, larvae are not abundant.

Aniphieosmoecus

canax (Oregon, Klamath Co., 8 June 1968, ROM)

A, larva, lateral x7; B, head and thorax, dorsal; C, case x5 280

Limnephilidae: Amphicosmoecus

20.2

281

20.3

Genus A n a b o l i a

D I S T R I B U T I O N AND S P E C I E S arctic region (Schmid 1950a). Five ranging westward to the plains, but foundland to Yukon and Colorado. 1960).

Species of this genus are widely distributed in the H o l are known from this continent; all occur in the east, A. bimaculata (Walk.) is transcontinental from NewLarvae have been described for three species (Flint

M O R P H O L O G Y Larvae have characteristic head markings of light yellowish brown w i t h relatively large, dark spots coalescing, especially on the frontoclypeal area, into irregular blotches ( B ) ; spotted head markings may also occur in Limnephilus, Grammotaulius, and Asynarchus, w i t h a tendency for coalescence of spots in some Limnephilus. Larvae o f Anabolia have a small patch of stout spines on the anterolateral corner of the pronotum (A, D ) ; these spines are also known in a few Limnephilus. The hind femur bears only two major setae on the ventral edge ( A ) . Chloride epithelia are present dorsally and laterally as w e l l as ventrally ( A ) . Abdominal gills are mostly two- or three-branched; and the anal claw usually bears three accessory hooks ( A ) . Identification o f Anabolia hinges on a combination o f these characters. Length o f larva up to 29 m m . C A S E Larval cases are made largely of elongate pieces of twigs, stems, or leaves arranged lengthwise ( c ) ; sometimes larvae of this genus construct three-sided cases o f broader pieces o f leaves (Flint 1960). Length of larval case up to 50 m m . B I O L O G Y Larvae inhabit marshes, slow-flowing streams, and temporary pools (Flint 1960; Wiggins 1973a). Gut contents o f larvae (3) examined were mostly pieces of vascular plant tissue; because of their widespread distribution and frequent local abundance these larvae are probably important detritivores i n lentic communities. The life cycle of A. bimaculata was studied by Berté and Pritchard (1986). Diapause occurs in the last larval instar o f the European A.furcata Brauer (Novak 1960), but is not known i n Nearctic species of Anabolia.

Anabolia bimaculata (Alberta, Blackfoot, 16 June 1962, ROM) A, larva, lateral x7, anal claw enlarged; B, head and thorax, dorsal, mesonotal setal areas detailed; C, case, ventral x3; D , spines on anterolateral corner of pronotum, lateral 282

Limnephilidae: Anabolia 20.3

283

20.4

Genus

Arctopora

D I S T R I B U T I O N AND S P E C I E S Arctopora is a small Holarctic genus. There are three species in North America: A. pulchella (Banks) is transcontinental and A. salmon (Smith) is recorded from Idaho; A. trimaculata (Zett.), is widespread in northern Eurasia, but extends into Alaska and the Yukon in a Beringian pattern (Wiggins and Parker, in press). Larvae of only A. pulchella

are known, reared by us in Ontario, and described by Flint

(1960). M O R P H O L O G Y Meso- and metanotal setae are reduced in number and confined to the primary areas; metanotal sal sclerites are lacking, and the sa 1 sclerites are very small (B). Setae of abdominal segment I are also reduced (A, D ) . Sclerotized parts of the head and thorax are light brown w i t h few markings except faint muscle scars. Most gills have two or three branches; chloride epithelia are present on the venter of segments ii-VH, and are apparent on the dorsum o f some segments as well (A). Length of larva up to 15 m m . CASE

The larval case o f A. pulchella

is constructed of pieces of grass or sedge arranged

longitudinally to form a cylinder of rather regular outline. Length of larval case up to 27 mm. BIOLOGY

A. pulchella

was reared from larvae collected in a temporary pool.

R E M A R K S These species have been treated under Lenarchulus (Schmid 1955), but Fischer (1969) pointed out that Arctopora Thomson is the valid name for the genus. Taxonomy o f adults was reviewed by Schmid (1952b) and Smith (1969).

Arctopora pulchella (Ontario, Algonquin Pro v. Park, M a y 1959, ROM) A , larva, lateral x l 2 ; B , head and thorax, dorsal; C, case, ventral x5; D , segment I , ventral 284

Limnephilidae: Arctopora 20.4

285

20.5 Genus Asynarchus A N D S P E C I E S Ten of the 16 species assigned to this genus occur in North America, where they are widespread across the northern half of the continent, extending south in the western mountains to Utah and Colorado. The remaining species occur in northern Eurasia; several species are Holarctic in distribution (Wiggins and Parker, in press). For the North American fauna, larvae have been described previously only for A. montanus (Banks) (Flint 1960, as A. curtus); we have associated larvae for seven species. D I S T R I B U T I O N

Larvae of Asynarchus usually have blotches or bands of contrasting colour on the dorsum of the head with three light areas in the narrowed part of the frontoclypeus ( B ) . Since there is a tendency for reduced contrast in these head markings, the genus is reached at two places in the key. In most larvae that we have, mesonotal sal setae range from two to eight on each side and are variable within species, but in European material studied by Solem (1983) mesonotal sal has one or two setae; one of these species is A. lapponicus Zetterstedt, which also occurs in North America. Larvae of Asynarchus with one mesonotal sal seta might be confused with Halesochila, but light areas on the dorsum of the head do not extend laterad of the frontoclypeal suture as they do in Halesochila (Fig. 20.20B). In most characters, larvae fit within the range of Limnephilus, and indeed the species of Asynarchus have been assigned to Limnephilus in the past. Chloride epithelia are, however, present dorsally on all Nearctic Asynarchus now known; dorsal chloride epithelia have not yet been found in Nearctic Limnephilus, but since they occur in some European larvae of this genus, this distinction is unlikely to hold for all species on this continent. Length of larva up to 23 mm.

M O R P H O L O G Y

Larval cases in this genus are constructed either of small rock fragments plant materials arranged lengthwise. Length of larval case up to 28 mm. C A S E

B I O L O G Y

(C)

or of

We have collected larvae in streams, ponds, and temporary pools.

R E M A R K S Some progress has been made in distinguishing among larvae of Asynarchus, Limnephilus, and Philarctus, but the diagnostic characters offered in the key are provisional until larvae of more species are known. Taxonomy of Asynarchus adults was reviewed by Schmid (1954b). The larva of A. rossi (Leonard and Leonard), which we have identified, will key to Limnephilus in the present work; based on characters of the adults, this species would be better placed in Limnephilus (F. Schmid, pers. comm.), and I have treated it accordingly.

Asynarchus circopa (Montana, Beaverhead Co., 7-8 July 1964, R O M ) A , larva, lateral x8, detail of dorsal chloride epithelia; B , head and thorax, dorsal, detail of mesonotum; C , case x5; D , segment I, ventral 286

Limnephilidae: Asynarchus 20.5

287

20.6 Genus Chilostigma A N D S P E C I E S This genus has been recognized in Scandinavia and Finland, and more recently in North America. A single Ne arctic species, C. itascae, is known from Minnesota (Wiggins 1975). Larvae of Chilostigma have not been positively identified. Two larvae collected at the type locality of C. itascae in Minnesota comply with characters of the Chilostigmini, and are unlike larvae of any species known in the Limnephilidae in North America. These larvae, illustrated here, are likely candidates for Chilostigma. D I S T R I B U T I O N

The head bears light posterodorsal muscle scars ( B ) . Each half of the pronotal plate is longer than wide; and each half of the mesonotal plate is wider than long. The metanotal sclerites at the sal and sal positions are relatively large and well developed. Abdominal gills are single. The lateral sclerite of the anal proleg bears several short setae together with longer ones ( A ) . Length of larva at least up to 11mm; the larva illustrated is not a final instar. M O R P H O L O G Y

C A S E The cases of the two larvae are constructed of small pieces of leaves and bark fastened together irregularly ( C ) . Length of larval case at least 12mm.

These larvae were collected in spring seepage areas of a wet meadow draining into a small, slow stream. The chronology of development in C. itascae may be unusual because adults were active on the surface of snow in February and March (Wiggins 1975). B I O L O G Y

Chilostigma itascae (?) (Minnesota, Itasca State Park, Clearwater Co., Nicollet Creek, August 1974, R O M ) A , larva, lateral xl2, detail of anal proleg; B , head and thorax, dorsal; c, case, x8; D , abdominal segment I, dorsal; E , dorsal sclerite of abdominal segment I X , dorsal 288

Limnephilidae: Chilostigma

20.6

289

20.7

Genus

Chyranda

D I S T R I B U T I O N AND S P E C I E S Chyranda centralis (Banks) is the sole species recognized in the genus. Its range extends across much of Canada to Q u é b e c , north to Alaska and south to California, Utah, and Colorado; our collection records indicate that the species is much more abundant i n the western part of the continent. The larva and pupa o f C. centralis

were described by Wiggins (1963).

M O R P H O L O G Y The larva of Chyranda bears little resemblance to any other. The head (B) is fairly uniform dark brown, smooth and shiny, round in circumference, and the dorsum somewhat flattened. The unusually large, irregular sclerite (A) at the base o f each lateral abdominal hump is diagnostic. On the venter o f abdominal segment I ( D ) the pair o f sal sclerites bearing several setae lie close together, the intervening space less than the length of one of the sclerites. Abdominal gills are single, forked lamellae are apparently absent, but a lateral fringe is well developed; chloride epithelia are present ventrally on segments III-VII. Length of larva up to 18 m m . C A S E The larval case ( c ) consists o f pieces of thin bark or stout leaves arranged to form a straight tube w i t h a prominent flange-like seam along each side. I n cross-section the case is broadly elliptical. Larval cases i n only Clostoeca (Fig. 20.9c) are similar. Length of larval case up to 35 m m . B I O L O G Y Larvae live i n small spring streams, and are usually found in accumulations of leaves. Pieces of vascular plants and moss were the dominant items i n guts of larvae (3) we examined.

Chyranda centralis (Oregon, Douglas Co., 9 June 1968, R O M ) A, larva, lateral x9, segment I enlarged; B, head and thorax, dorsal; C, case, ventrolateral x5 (California, Yosemite National Park, 13 June 1961, R O M ) ; D , abdominal segment I , ventral 290

Limnephilidae: Chyranda 20.7

291

20.8

Genus C l i s t o r o n i a

D I S T R I B U T I O N AND S P E C I E S This genus is confined to North America, where four species are distributed over western montane areas from Alaska to Arizona. A n additional species was described from M e x i c o at an elevation o f 8800 feet (approx. 2700 m) (Denning and Sykora 1966; Flint 1967c). Larval diagnosis for Clistoronia is based on material of C. magnified (Banks) we reared from localities in British Columbia, Oregon, and Washington (Wiggins 1977). M O R P H O L O G Y The larva o f C. magnified has head markings generally similar to those of related genera such as Limnephilus and Asynarchus, but the venter of abdominal segment I is unusually setose, w i t h more than 100 setae in all setal positions combined, merging from both sides (D). The head and pronotum are covered w i t h small spines (B), and the lateral sclerite o f the anal proleg bears several short, stout setae (A). Most gills are threebranched. Length of larva up to 28 m m . CASE

The larval case (C) is composed of small pieces of wood arranged irregularly to

form a cylinder w i t h little curvature or taper. I n our associated series of C. mdgnificd

from

Washington a new case o f fine rock fragments was constructed during the final instar. Length of larval case up to 34 m m . B I O L O G Y Species o f Clistoronid generally occur at higher elevations; larvae o f C. nmgnifica live in ponds and small lakes. According to Winterbourn (1971a), who studied the life history o f C. mdgnificd in M a r i o n Lake, British Columbia (elev. approx. 300 m), o v i position occurred i n August and September, larvae fed primarily on detrital materials in bottom sediments, and grew quickly to overwinter as final instars; adults emerged in M a y and June, but apparently did not become sexually mature until late summer. I n a population o f C. mdgnificd that we sampled at a higher elevation, adults evidently emerged later (Washington, M t Rainier National Park, elev. approx. 1500 m , pupae 4 July). R E M A R K S Clistoronid mdgnificd has been reared under laboratory conditions continuously for 14 years through 30 generations (Anderson and Belnavis 1991); ultimate loss o f the culture was attributed to the effects of inbreeding.

Clistoronid mdgnificd (Oregon, Jefferson Co., 1 June 1968, ROM) A, larva, lateral x7, anal proleg enlarged; B, head and thorax, dorsal; C, case x3; D, segment I, ventral 292

Limnephilidae: Clistoronia 20.8

293

20.9 Genus C l o s t o e c a DISTRIBUTION

AND SPECIES

This genus occurs only in western North America,

from California to British Columbia, and possibly to Alaska (Flint 1960). A l l populations are currently recognized as a single, somewhat variable, species C. disjuncta

(Banks).

The larva was described by Flint (1960); we reared larvae from Oregon. M O R P H O L O G Y Sclerites o f the head and thoracic nota are uniform reddish to yellowish brown, shiny and smooth, marked only by faint muscle scars ( B ) ; mesonotal setae are sparse, the primary setal areas widely separated. I n some specimens t w o small sclerites are apparent at the dorsal and posterior edges o f the lateral humps o f segment I (E), but often these are very faint or not evident ( A ) ; the generic key is designed to retrieve Clostoeca with both conditions. Larvae o f Clostoeca differ from Chyranda in the ventral setation o f segment I ; the sal sclerites are widely separated, and the intervening space is several times larger than one o f the sclerites (D). Ventral chloride epithelia are present on segments I I v i i , and gills are single; forked lamellae are lacking, but the lateral fringe is well developed. Length o f larva up to 14 m m . C A S E The larval case i n Clostoeca is constructed o f leaf pieces and is similar only to Chyranda because o f the lateral flanges. In some specimens the flanges are much wider than in Chyranda and there are fewer individual pieces i n the entire case ( C ) ; but i n others the cases are similar to Chyranda (Fig. 20.7c). Length o f larval case up to 18.5 m m . B I O L O G Y Larvae we reared in Oregon were collected under wet leaves in a spring seepage area.

Clostoeca disjuncta (Oregon, Benton Co., 8 A p r i l 1964, ROM) A , larva, lateral x l l ; B , head and thorax, dorsal, detail o f mesonotum; c, case, ventral x8 (Oregon, L i n c o l n Co., 23 March 1982, ROM); D, E, abdominal segment I ; D, ventral; E, lateral 294

Limnephilidae: Clostoeca 20.9

295

20.10 Genus Cryptochia D I S T R I B U T I O N

A N D

S P E C I E S

Seven species are known in this genus, all confined to

western North America. We have collected larvae in mountainous sections of Alberta, British Columbia, California, Idaho, Montana, Oregon, Washington, and Wyoming. Larvae of Cryptochia pilosa (Banks) were associated in Oregon (Wiggins 1977); the larva described as Dicosmoecinae 1 by Flint (1960) belongs to this genus. Larvae of Cryptochia are unusual. The anterior edge of the pronotum bears a dense fringe of very long setae ( A ) , often heavily laden with sand and silt. The dorsum of the head is flattened and bears a peripheral carina thickly beset with setae, and the frontoclypeal apotome bears two bands of dense setae (B). The ventral apotome has concave lateral margins terminating posteriorly in a sharp point ( E ) , and sclerites of the submentum and stipes bear many long setae ( F ) . The legs bear small spines in comb-like clusters ( D ) . Dorsal and ventral abdominal gills are of one or two filaments, but most of the lateral gills have four filaments; forked lamellae are lacking. Length of larva up to 8 mm. M O R P H O L O G Y

C A S E The unique larval cases of Cryptochia ( C ) are flattened, tapered strongly from front to rear, and are made of plant materials arranged transversely. The smooth outer surface of the posterior part of the case suggests that the larva shapes the rough edges with its mandibles. The compressed layered structure of the case appears to retain moisture like a sponge, and also provides buoyancy (Wisseman and Anderson 1987); larvae of C. pilosa float in their cases in water, lodging along the edge of the stream until they can crawl up on the damp shore. Length of larval case up to 13 mm.

We have found larvae in a wide range of small, cold, spring streams, usually in mountainous terrain. Some larvae were found beneath the water surface in areas of little current, but most were collected above the surface on pieces of wet wood or in wet leaves at the water's edge. Pupae have been found in similar wet logs above the water surface. The life cycle of C. pilosa studied by Wisseman and Anderson (1987) extended over two years; most larvae lived in damp, decaying leaves and wood above the water surface, probably feeding mainly on fungi. B I O L O G Y

A key to males of seven species was provided by Denning (1975). The type species of Cryptochia, C. pilosa (Banks), was originally assigned to the European genus Parachiona (Ross 1944: 297). R E M A R K S

Cryptochia pilosa (Oregon, Douglas Co., 9 June 1968, R O M ) A , larva, lateral x25; B , head and thorax, anterolateral; c, case, anteroventral xl4; D , middle leg, lateral, spines enlarged; E , head, ventral; F, maxilla and half of labium, ventral 296

Limnephilidae: Cryptochia 20.10

297

20.11 Genus Desmona A N D S P E C I E S This is a North American genus of two species: D. bethula Denning from California, and D. mono (Denning) from Idaho, Oregon, Washington, and Wyoming as well as California (Wiggins and Wisseman 1990). D I S T R I B U T I O N

Desmona larvae can be recognized by two small, ring-shaped sclerites on abdominal segment I at the base of each lateral hump ( A ) (Wiggins 1977). The head and thorax are dark to reddish brown without prominent markings; fine spines cover most sclerotized surfaces, and small secondary setae on the dorsum of the head are variable in D. bethula but absent in D. mono. Mesonotal setal areas 1, 2, and 3 are confluent, and some metanotal setae usually arise from the membrane between the primary sclerites ( B ) , although the metanotal setae are highly variable and sometimes lacking between the sal sclerites. The prosternai horn is long, and coxae of the hind and middle legs have coarse spines scattered over their anterior surfaces. Abdominal segment I bears 18-30 setae on each side of the dorsal hump, approximately 10 setae both dorsad and ventrad of each lateral hump, and many setae ventrally ( A ) ; gills are single, although somewhat variable on V I I and V I I I , and chloride epithelia are present ventrally on segments I I - V I I . The sclerite on abdominal segment I X bears many setae and a row of approximately 20 fine setae extends across the posterior margin of V I I I ( D ) ; lateral sclerites of the anal prolegs bear several stout, clear setae. Length of larva up to 15 mm. M O R P H O L O G Y

The larval case ( C ) is made of coarse sand and organic debris in varying proportions. Length of larval case up to 17 mm. C A S E

Larvae live in slow currents of small spring runs and seepage areas of alpine meadows, frequently buried in sand deposits where pupation occurs; final-instar larvae occur in summer, and adults emerge in September and October. Larvae of D. mono also occur in the littoral zone of small alpine lakes. At dusk, final instar larvae of D. bethula crawl up stream-side sedges and other vascular plants to feed on leaves and flowers, returning to the stream by sunrise (Erman 1981); gut contents of these larvae were primarily vascular plant fragments with some diatoms. Late- instar larvae of D. mono also feed out of water nocturnally (Wiggins and Wisseman 1990), but larvae were not observed to crawl up the plants as D. bethula do. Ingestion of living vascular plant tissue is unusual among larval Trichoptera, as is leaving the water to feed where there is no spray zone. Correlation between larval head width and instar has been established for D. bethula (Erman 1981, fig. 5). B I O L O G Y

R E M A R K S The genus was revised and taxonomic information on all stages summarized by Wiggins and Wisseman (1990). Assignment of D. mono to a new genus Monophylax (Nimmo 1991) is not followed here.

Desmona bethula (California, Nevada Co., 20 July 1966, R O M ) A , larva, lateral xlO, hind femur and abdominal segment I enlarged; B , head and thorax, dorsal; C , case x8; D , segments V I I I and I X , dorsal 298

Limnephilidae: Desmona

20.11

299

20.12 Genus Dicosmoecus A N D S P E C I E S This is a Holarctic genus confined to western North America, eastern Russia, and Japan. Four species occur in montane areas of North America from Yukon and Alaska to California and New Mexico. We have associated larvae for all four species. D I S T R I B U T I O N

Larvae are large and stout-bodied; the head and thorax are reddish brown to black. Flattened scale-hairs are lacking, but the pronotum is variously provided with stout setae and the anterior margin in some species bears large spines ( B ) . The tibiae of all legs have several pairs of stout spur-like setae ( A ) , and there are metanotal setae on the membrane between the primary sclerites ( B ) . Abdominal segment I bears many setae, variable in number ( D , E ) ; gills have 2-4 filaments and are variable ( A ) ; segment VII bears a single prominent seta, and sometimes one or two smaller setae on each side of the middorsal line ( F ) ; a band of 20 to 40 setae extends ventrad from each side of the dorsal sclerite of I X ( A ) . Length of larva up to 28 mm. M O R P H O L O G Y

Final-instar larvae have a characteristic stout case of fine gravel, slightly curved, and somewhat flattened but little tapered ( C ) ; the anterior lip of the case at larval maturity is heavily coated with silk. In the early instars cases are made largely of plant materials (Hauer and Stanford 1982, fig. 3), and examples showing the abrupt transition from plant to mineral materials (Lepneva 1966, fig. 117) are occasionally collected. Length of case up to 36 mm. C A S E

Larvae usually live on rocks in running waters, although they also occur along the shores of lakes. Larvae of D. gilvipes graze diatoms and fine organic particles on rock surfaces. Larvae of the other three North American species are generalized predatorshredders in the final instar at least, and usually require two years for completion of the life cycle (e.g. Gotceitas and Clifford 1983). Consistent with their grazing habit, larvae of D. gilvipes have rather slender scoop-like mandibles from which the thin toothed points are soon eroded against rock surfaces, leaving a scraping edge (Wiggins and Richardson 1982, figs. 31, 32); larvae of the detritivorous species have stouter toothed mandibles. The two common species, D. atripes and gilvipes, rarely occur at the same site although they are geographically sympatric over much of their range. Larvae fix their cases to the underside of rocks in midsummer, remaining in diapause for several weeks before metamorphosis takes place, and adults emerge in late summer and early autumn. Larvae of Dicosmoecus pupate in aggregations, a behavioural pattern studied by Gotceitas (1985) in D. atripes. B I O L O G Y

R E M A R K S Keys to species for larvae and adults were provided in a revision of the genus by Wiggins and Richardson (1982); ecology and phylogeny were also considered.

Dicosmoecus gilvipes (Oregon, Jefferson Co., 19-23 Sept. 1966, R O M ) A , larva, lateral x5, middle tibia enlarged; B , head and thorax, dorsal, detail of mesonotum; C , case, ventrolateral x3; D , segment I, dorsal; E , segments I and II, ventral; F, segments V I I , V I I I , I X , dorsal 300

Limnephilidae: Dicosmoecus

20.12

301

20.13

Genus

Ecclisocosmoecus

D I S T R I B U T I O N AND S P E C I E S This is a genus of two species: the type species from Sakhalin (Schmid 1964a), and E. scylla ( M i l n e ) from western North America. For many years the latter was assigned to Ecclisomyia, but when the larva was discovered it was evident that E. scylla was not congeneric w i t h Ecclisomyia spp. (Wiggins 1975). We have collected larvae i n British Columbia, Oregon, and Washington; and adults were taken in Alaska (Ellis 1978). The larva o f Ecclisocosmoecus was associated through material from M t Hood, Oregon (Wiggins 1977). M O R P H O L O G Y The head and pronotum are bright uniform brownish red in colour, and have a finely pebbled texture; both are inflated in lateral aspect and wide in dorsal aspect, the pronotum strongly constricted at its posterior margin (A, B). Mesonotal setae are largely continuous from sal to sal to sa3; some metanotal setae arise from the membrane between the sal sclerites (B). The lateral abdominal fringe does not extend across segment v i i i ; abdominal gills are single, and ventral chloride epithelia occur on segments III-VII. Length of larva up to 17 m m . C A S E Larval cases o f E. scylla (C) are made of sand grains closely fitted into a smooth exterior surface; the case has a pronounced taper and curvature. Length o f larval case up to 19 m m . B I O L O G Y Larvae o f Ecclisocosmoecus occur in small, cold mountain streams; most o f those we collected were concealed i n sand and gravel. Pupal cases are fastened to rocks, adults emerging in June and July; the range of larval instars in some collections indicates that more than one year may be required for a generation. Guts of larvae (3) we examined contained pieces of vascular plants and moss w i t h fine organic particles. REMARKS under

Diagnostic characters of the male o f E. scylla

were given by Ross (1950,

Ecclisomyia).

Ecclisocosmoecus scylla (Oregon, Clackamas Co., 23-29 Sept. 1966, ROM) A, larva, lateral x l O ; B, head and thorax, dorsal, detail o f mesonotum; C, case, x7 302

Limnephilidae: Ecclisocosmoecus 20.13

303

20.14

Genus

Ecclisomyia

D I S T R I B U T I O N AND S P E C I E S Ecclisomyia is a small genus o f the Nearctic and Asian Palaearctic regions. Three North American species are confined to western montane areas, ranging as a group from Alaska to California. Larvae have been described previously for E. conspersa Banks (Flint 1960) and for a Siberian species E. digitata (Martynov) (Lepneva 1966); we have associated larvae for all three North American species. M O R P H O L O G Y Larvae o f Ecclisomyia can be recognized by the large size of the metanotal sal and sal sclerites in relation to the area of the metanotum (B); the distance between the sal sclerites is approximately two or three times the largest dimension of one sal sclerite. Metanotal sal sclerites in some Psychoglypha may approach the diagnostic condition of Ecclisomyia, but the genera can be distinguished by other characters outlined. The light-coloured stripe on the mid-dorsal line o f the pro- and mesonota and the coronal suture i n the illustration occurs in both E. maculosa Banks and conspersa Banks but not in E. bilera Denning. Mesonotal setal areas are continuous from sal to sal to sa3. Typically for the Dicosmoecinae, the middle and hind femora bear more than two major setae ventrally (A). Abdominal segment I bears many setae, often with small sclerites incorporating the bases of several of them; gills are single. Length of larva up to 19 m m . C A S E Larval cases in Ecclisomyia (C) tend to be more slender than in most other l i m nephilids and are straight with little taper; they are constructed of rather coarse rock fragments, often incorporating some long pieces of plant materials. Length of case up to 31 mm. B I O L O G Y Larvae o f Ecclisomyia live in cool mountain streams, among rocks and gravel. In guts of larvae (3) we examined, diatoms were the dominant part of the contents, w i t h small amounts of vascular plant pieces and fine organic particles. Fine organic particles were found to be the major component in the food o f E. maculosa, w i t h a small proportion of vascular plant fragments (Mecom 1972a). R E M A R K S Diagnostic characters reviewed by Ross (1950).

of males

of the North American species were

Ecclisomyia conspersa (Oregon, L i n n Co., 1 June 1968, ROM) A, larva, lateral x l l ; B, head and thorax, dorsal; C, case x5 304

Limnephilidae: Ecclisomyia 20.14

305

20.15

Genus

Eoeosmoecus

D I S T R I B U T I O N AND S P E C I E S Two species are assigned to this North American genus: E. frontalis (Banks) in Washington, Oregon, and western British Columbia; and E. schmidi (Wiggins) in Idaho, Montana, and eastern British Columbia (Wiggins and Richardson 1989). M O R P H O L O G Y Larvae o f Eoeosmoecus are similar to Onocosmoecus but can be distinguished by setal characters. Segment VII in Eoeosmoecus bears a single long seta on each side of the mid-dorsal line, sometimes w i t h one or two smaller setae on each side (C); in a row of 10-14 erect setae behind the anterior margin o f the pronotum, the setae are more widely spaced than i n Onocosmoecus, particularly on each side of the mid-dorsal line (D), and the lateral setae are shorter than the others. U n l i k e some other dicosmoecine genera, larvae of Eoeosmoecus lack the broad, median, light band on the coronal suture of the head, pronotum, and mesonotum, although a narrow median band sometimes occurs on the thoracic sclerites. Metanotal setae are confined to the primary sclerites (D). A b d o m inal gills have 2 - 4 filaments, lateral gills are usually absent from segment v and sometimes IV, or terminate at the anterior position of IV (A). Length of larva up to 21 m m . C A S E A l t h o u g h cases of early instars of both species are made of pliable plant materials, final-instar larvae of the two species of Eoeosmoecus construct cases of different materials. The stout wood-fragment cases of E. frontalis (E) are usually found on submerged logs, but the mineral cases of E. schmidi (B) are buried in gravel. I n one population of E. frontalis, some larvae were found constructing gravel cases similar to those of E. schmidi, others occupied and pupated in cases of a Philocasca species, and others constructed typical wood cases (Wiggins and Richardson 1989). I n preparation for pupation, larvae construct a posterior silken sieve membrane w i t h i n the larval case, an unusual behaviour known also i n Onocosmoecus. Length of larval case up to 22 m m . B I O L O G Y Larvae live in cold spring streams at higher elevations and at least two years are required for completion of the life cycle. Larvae o f E. schmidi leave the water at night to feed on stream-side vascular plants (White and Brusven 1994). The two Eoeosmoecus species present an unusual situation because adults are very close morphologically, but the species are most clearly distinguished by larval case-making behaviour and habitat. REMARKS

Taxonomy and biology of the species of Eoeosmoecus

were studied by W i g -

gins and Richardson (1989).

Eoeosmoecus schmidi (Montana, Missoula Co., 24 June 1968, R O M ) A, larva, lateral x6; B, case, ventrolateral x4; c, abdominal segments vu, vin, IX, dorsal Eoeosmoecus frontalis (Oregon, Marys Peak, 5 July 1963, R O M ) D, head and thorax, dorsal x l 6 w i t h detail o f pronotum; E, case, ventral x3 (From Journal of the North American Benthological Society) 306

Limnephilidae: Eocosmoecus 20.15

307

20.16

Genus F r e n e s i a

D I S T R I B U T I O N AND S P E C I E S Frenesia is a Nearctic genus, with two species F. difficilis (Walker) and F. mi s sa (Milne) confined to the northeastern part of the continent, roughly within the area bounded by Nova Scotia, North Dakota, and Virginia. The larva o f F. difficilis was described by L l o y d (1921, under Chilostigma), and of F. mis sa by Ross (1944). Larvae of both species were described and distinguished by Flint (1956); we have associated larvae for both. M O R P H O L O G Y Sclerites of the head and thorax in these larvae are light brown with few markings other than light muscle scars on the posterior part of the head. The head is covered w i t h tiny spines; the pronotum bears stout, spine-like setae, especially along the anterior margin (B); and in contrast to Glyphopsyche the legs are not banded. On the venter of abdominal segment I , sal and sal are conjoined ( D ) . Most abdominal gills are two-or three-branched, a few consisting of a single filament (A); chloride epithelia are present on the venter o f segments I l - V i i . The lateral sclerite of the anal proleg bears stout spine-like setae similar to those of Glyphopsyche (A). Length of larva up to 17 m m . C A S E Larval cases in Frenesia are mainly o f rock fragments, often with small bits of wood added (C). Length of case up to 21 m m . B I O L O G Y A n extensive account of the biology of both species has been provided by Flint (1956). Larvae live in cold streams and spring seepage areas, where they feed on leaves and decaying wood ( L l o y d 1921). Larvae reach the final instar in September and October, pupate, and emerge as adults i n November. REMARKS

Frenesia

Taxonomy o f adults was reviewed by Schmid (1952c).

difficilis

(Ontario, York Co., 11 Sept. 1953, ROM)

A, larva, lateral x l O ; B, head and thorax, dorsal, detail o f mesonotum; C, case x5; D, segment I , ventral 308

Limnephilidae: Frenesia 20.16

309

20.17

Genus

Glyphopsyche

D I S T R I B U T I O N AND S P E C I E S The genus Glyphopsyche is confined to the Nearctic region. Two species are known: G. irrorata Fab., northern and transcontinental from Newfoundland to the western mountains and from Alaska to California; and G. missouri Ross, recorded only from Missouri. Larvae have been described and assigned to both species: G. missouri by Ross (1944) and Flint (1960); and G. irrorata by Flint (1960) although no positive evidence of association was available for the latter species. We have reared larvae o f G. irrorata and have collected them at many localities from Ontario to British Columbia. M O R P H O L O G Y Few of the Limnephilinae larvae in North America have dark-coloured bands on the legs (A); among those w i t h single gills are only certain species o f Psychoglypha, and of those w i t h branched gills, there are only species o f Glyphopsyche. Larvae of this genus have stout, sharp setae on the lateral sclerite of the anal proleg (A) and on the anterior edge of the pronotum (B). Length of larva up to 21 m m . CASE

Larval cases range from a rather evenly contoured cylinder of rock and plant

pieces (C) to irregular cases incorporating larger wood pieces arranged longitudinally. Length of case up to 34 m m . B I O L O G Y For the most part, Glyphopsyche irrorata is a species of marshes and the edges of slow streams; larvae are often associated w i t h an abundance of decaying vegetation. Data from our collections indicate that larvae are i n the final instar by late summer; adults have been collected from September through most winter months to May. REMARKS

Schmid (1952c) has reviewed taxonomy of the adults.

Glyphopsyche irrorata (California, Lake Co., 6 Sept. 1946, ROM) A, larva, lateral x7, anal proleg enlarged; B, head and thorax, dorsal; C, case, lateral x4 310

Limnephilidae: Glyphopsyche 20.17

311

20.18

Genus

Grammotaulius

D I S T R I B U T I O N A N D S P E C I E S Grammotaulius is a northern genus widespread over much o f the Hoi arctic region. Five species are known in North America and these are largely western and montane from Alaska to Colorado; one species, G. interrogationis Zett., is transcontinental across the northern part of the continent as far south as Minnesota and occurs also in Greenland. Larvae have been identified for only one North American species, G. lorettae Denning from Colorado (Flint 1960). Larvae of four Eurasian species have been described (Lepneva 1966). M O R P H O L O G Y Although there is still much to learn about the North American species of Grammotaulius, the consensus from the Holarctic fauna is that larvae have a light, yellowish brown head, bearing numerous small, dark spots ( B ) . North American larvae I have examined, apparently of this genus, have all three setal areas separate on both dorsum and venter of abdominal segment I (D, E), w i t h 1-3 setae at ventral sal. Length of larva up to 34 m m . C A S E Larval cases i n Grammotaulius ( C ) are made of lengths of sedge or similar leaves arranged lengthwise. Length o f larval case up to 41 m m . B I O L O G Y The larvae of G. lorettae described by Flint (1960) were collected in a small weed-filled pond near the tree line in Colorado. The habitat of G. betteni H.-G. was described by H i l l - G r i f f i n (1912) as small ponds and slow streams at much lower elevations around Corvallis, Oregon, and she also observed that although adults of this species emerged i n M a r c h and A p r i l , they were on the wing in September, October, and N o v e m ber. It seems likely, then, that in at least some of the North American species of Grammotaulius, adults emerging in spring are in diapause, their sexual maturity and flight activity delayed until the onset of a shorter photoperiod i n late summer; and i n fact the European G. atomarius Fab. was one of the species studied in the elucidation of this type of life cycle i n Trichoptera (Novak and Sehnal 1963, 1965). REMARKS taulius.

Grammotaulius

Schmid (1950b, 1964b) has reviewed taxonomic data for adults of Grammo-

sp. (Utah, Summit Co., 12 June 1961, ROM)

A, larva, lateral x5, segment I enlarged; B, head and thorax, dorsal, detail of mesonotum; c, case, ventral x3; D, segment I , dorsal; E, segment I , ventral; F, segments v m and IX, dorsal 312

Limnephilidae: G r a m m o t a u l i u s

20.18

313

20.19

Genus

Grensia

D I S T R I B U T I O N A N D S P E C I E S The single boreal species, G. praeterita (Walker), is common to both Palaearctic and Nearctic regions. In North America the records available indicate that the species occurs in arctic tundra areas of the Northwest Territories, Yukon, and Alaska, extending northward at least to Victoria Island, and east to Greenland. The larva was identified from an associated series of larvae and pharate adults from the Northwest Territories (Wiggins 1977). M O R P H O L O G Y The pronotal plates and the head are covered w i t h tiny spines (B), the head is dark brown in colour w i t h some muscle scars; mesonotal sal and sal are separated by a gap without setae. The lateral hump o f abdominal segment I lacks basal sclerites, and gills are single. Typically for the Chilostigmini, the lateral sclerites of the anal prolegs bear many stout, clear setae (D). Length o f larva up to 14 m m . CASE

For their cases larvae use small pieces of woody plant tissue, some rock frag-

ments, and organic materials with concentric rings that appear to be opercula of prosobranch snails ( C ) . Length of larval case up to 16 m m . B I O L O G Y This is one of the few truly arctic species of Trichoptera (Wiggins and Parker, i n press). Our material indicates that G. praeterita is an inhabitant of lakes located beyond the northern l i m i t of trees; but we have one series of larvae from Alaska, apparently of this genus, with the habitat note 'seeps i n cliffs.' R E M A R K S Most of our larval and pupal specimens to date have come from stomachs of Arctic char collected by the Arctic Survey of the Fisheries Research Board of Canada. Diagnostic characters of adults were illustrated by Betten and Mosely (1940, under Frenesia).

Grensia praeterita (Northwest Territories, D r i n k Lake, 12 Sept. 1956, ROM) A, larva, lateral x l O ; B, head and thorax, dorsal, portion o f pronotum enlarged; C, case, lateral x7; D, segment IX and anal prolegs, dorsal 314

Limnephilidae: G r e n s i a

20.19

315

20.20

Genus

Halesochila

D I S T R I B U T I O N AND S P E C I E S The genus Halesochila is confined to western North America, where a single species, H. taylori (Banks), is known. Larvae have been identified from a series we reared in British Columbia, and we have collected larvae evidently congeneric with them from many localities in Oregon and Washington (Wiggins 1977); adults have been recorded from Idaho (Smith 1965) and Alaska (Vineyard 1982). M O R P H O L O G Y Three dark and often indistinct bands on the head are characteristic of H. taylori, as is a single seta in the mesonotal sa 1 position (B). Dorsal chloride epithelia are present i n addition to lateral and ventral series (A). The venter of abdominal segment I is heavily setate in all three primary positions ( D ) . Most abdominal gills are threebranched (A). Length o f larva up to 24 m m . Some Asynarchus (q.v.) larvae are now known also to have a single seta in the mesonotal sal position; larvae o f Halesochila can be distinguished by the colour pattern on the dorsum of the head, where wider light areas extend laterad of the frontocylypeal apotome. C A S E Larval cases are usually constructed of leaf pieces or wood fragments laid flat to form a cylinder o f rough exterior (C), although not always as wide at the anterior end as in the illustration; some larvae in our collection, apparently o f this genus, have three-sided cases of large pieces of leaves. Final instars construct cases of fine gravel. Length of larval case up to 35 m m . B I O L O G Y Larvae live in small lakes and ponds, some of the latter reputed to be temporary. Life-history data compiled by Winterbourn (1971a) show that food of larvae in a small British Columbia lake was largely detritus, and that larvae of this species grew rapidly in spring and early summer to reach the final instar from June to September; pupae were found partially buried in bottom sediments. Adults are active in October. REMARKS

Halesochila

Taxonomic data for adults o f / / , taylori were provided by Schmid (1950c).

taylori (British Columbia, Vancouver Is., M a y 1965, ROM)

A, larva, lateral x7; B , head and thorax, dorsal, detail of mesonotum; c, case, lateral x4; D, segment I , ventral 316

Limnephilidae: Halesochila 20.20

317

20.21 Genus Hesperophylax D I S T R I B U T I O N A N D S P E C I E S Hesperophylax is exclusively aNearctic genus widely distributed through much o f the continent. Seven species are known: five in the west, one in M e x i c o , and one wide-ranging, transcontinental and western montane species, H. désignât us (Walker).

Larvae o f Hesperophylax have long been known (Vorhies 1905, 1909, and L l o y d 1921, as Platyphylax; Ross 1944; Flint 1960). From study of associated series o f larvae and adults, diagnostic characters were established for three species, but others, including H. designatus, cannot be distinguished (Parker and Wiggins 1985); however, any larvae o f this genus found east of the Great Plains are likely to be H. designatus. M O R P H O L O G Y This is one of the few limnephilid genera in which most gills of the dorsal and ventral series have four or more branches ( A ) . Chloride epithelia occur ventrally on segments H-Vll; the lateral fringe extends from II or III to VIII. Mesonotal sal has several setae, and setae are numerous on the metanotal membrane between the primary sclerites ( B ) . Femora of the second and third legs have only two major setae along the ventral edge ( A ) . The head is medium brown w i t h few markings save for some dark muscle scars; fine spines cover much o f the dorsum. Length of larva up to 33 m m . C A S E Most cases consist entirely of rock fragments (C), but larvae of western species sometimes incorporate small pieces of wood; cases are cylindrical, and often much more irregular than illustrated when larger pieces are used. Length of larval case up to 40 m m . B I O L O G Y Larvae of most Hesperophylax species are found in running waters, but species appear to have broad tolerances for they occur i n intermittent streams, cold spring seeps, spring runs, streams, rivers, and lakes. I n lentic habitats larvae normally are found in shallow water, but have been found as deep as 20 m. Water temperatures of larval habitats range from 3 to 3 1 ° C . Apparently all species are univoltine, overwintering as fourth and fifth instars, w i t h pupation beginning in late February or March; emergence usually occurs from March through September. Gut analyses indicate that larvae o f all species feed mainly on detritus but are opportunistic omnivores (Parker and Wiggins 1985); food items ingested include vascular plants, filamentous algae and diatoms, insects, and unrecognizable detritus. Extended observations on biology and behaviour of H. designatus were recorded by Vorhies (1905, 1909) and L l o y d (1921); young instars o f H. designatus feed mainly on diatoms, older larvae ingest vascular plant materials as w e l l . The biology of H. occidentalis (Banks) was studied in Colorado by Martinson and Ward (1982). R E M A R K S Taxonomy of adults and larvae was revised by Parker and Wiggins (1985), and distributional and biological information summarized; hypotheses of phylogeny and biogeography were proposed.

Hesperophylax designatus (Ontario, Durham Co., 13 M a r c h 1966, ROM) A, larva, lateral x7, middle femur enlarged; B, head and thorax, dorsal, detail of mesonotum; C, case, lateral x5 318

Limnephilidae: H e s p e r o p h y l a x

20.21

319

20.22 Genus Homophylax A N D S P E C I E S This genus is exclusively Nearctic, represented throughout western montane parts of the continent from Alaska to California. Ten species are known. Larvae of Homophylax were identified from material we associated for three species (Wiggins 1977), and we have taken larvae generally similar to these at many other localities. D I S T R I B U T I O N

Larvae of Homophylax are most similar to those of Psychoglypha, but material available indicates that the two can be separated by the form of the sclerite at the base of each lateral hump of abdominal segment I; in Homophylax the sclerite is a short bar along the posterior edge of the hump ( A ) . Sclerotized parts of the head and thorax in Homophylax larvae are medium brown without contrasting markings; muscle scars are ring-like with clear centres. The anterior border of the labrum is unpigmented but not especially membranous ( D ) . Femora have only two major setae on the ventral edge. Abdominal gills are single and forked lamellae are lacking; the dorsal sclerite of segment I X bears many setae ( E ) . Length of larva up to 21 mm. M O R P H O L O G Y

C A S E Larval cases of late-instar Homophylax are usually constructed of thin pieces of bark arranged irregularly into a smooth-walled cylinder with relatively little taper or curvature; the thin walls are often flexible. Cases of this type ( C ) are usually diagnostic for Homophylax, although occasionally larvae have a three-sided case; pieces of rock are sometimes utilized as well, making distinction from Psychoglypha difficult. Length of larval case up to 25 mm.

Larvae we collected were restricted to small, cold streams on mountain slopes, where they are most often concealed in fine gravel or accumulations of leaves. Adults of different species occur at various times through spring and summer months. B I O L O G Y

R E M A R K S

A taxonomic review of adults was provided by Denning (1964).

Homophylax andax (Washington, Mt Rainier National Park, 3 July 1969, R O M 690164) A , larva, lateral x8, segment I enlarged; B , head and thorax, dorsal; C , case, lateral x5; D , labrum, dorsal; E , segment I X and anal prolegs, dorsal, lateral seta of basal tuft enlarged 320

Limnephilidae: Homophylax 20.22

321

20.23

Genus

Hydatophylax

D I S T R I B U T I O N AND S P E C I E S Hydatophylax is a genus of the Holarctic region, w i t h four North American species. I n the east, / / . argus (Harr.) is widespread from South Carolina to Q u é b e c and west to Minnesota; H. victor Banks is k n o w n only from the northeast. I n the west, H. hesperus (Banks) occurs from Alaska to California; H. variabilis (Mart.), a species widespread i n northern Europe and Siberia, has been recorded from Alaska. Larvae have been described for H. argus ( L l o y d 1915, as Astenophylax\ Flint 1960); we associated larvae for H. hesperus, illustrated here, in Oregon and Washington, and have material of H. variabilis. M O R P H O L O G Y Similarity between Hydatophylax and some Pycnopsyche larvae complicates generic identification, as is evident in the key. Hydatophylax larvae have fused metanotal sal sclerites (B, D), and one species (H. argus) has chloride epithelium on the venter of abdominal segment I I ; larvae o f the western H. hesperus (A) differ from H. argus in lacking chloride epithelium on segment I I , and in having a tuft of 3-6 setae on segment IX laterad of the dorsal sclerite. In both species, sclerotized parts of the head and thorax are light to medium brown and have diffuse spots somewhat like those in Anabolia. Larval taxonomy i n Hydatophylax may be even more complex because the larva of H. victor is unknown, and subterminal instars may not have the diagnostic patterns of abdominal setae. As i n Pycnopsyche, an elongate sclerite lies along the posterior margin of each lateral hump, and gills are single. Length of larva up to 35 m m . C A S E Typical larval cases in Hydatophylax are constructed o f bulky pieces of wood and leaves (C); H. argus probably constructs a larger case than any other North American caddisfly. The cases are irregular; occasionally a larva i n a flattened case of leaves is found. Length of larval case up to 76 m m . B I O L O G Y Larvae o f Hydatophylax live i n streams, often small but not exclusively so. They are largely confined to accumulations o f plant debris or to vegetation along the edge; H. argus feeds on dead wood and bark ( L l o y d 1921). R E M A R K S A taxonomic review of adults was provided by Schmid (1950d); the genus was previously k n o w n as Astenophylax.

Hydatophylax hesperus (Oregon, L i n c o l n Co., 10 July 1963, ROM) A, larva, lateral x6, segments I and IX enlarged; B, head and thorax, dorsal; C, case lateral x2; D, fused metanotal sal sclerite enlarged 322

Limnephilidae: Hydatophylax 20.23

323

20.24

Genus I r o n o q u i a

D I S T R I B U T I O N AND S P E C I E S Ironoquia is a Holarctic genus. I n North America four species are known, all within the eastern part of the continent from Nova Scotia to L o u i s i ana and Wisconsin; a fifth species is widely distributed in Europe. Larvae were described for /. punctatissima (Walker) and /. parvula (Banks) by Flint (1960). There is associated material for /. lyrata (Ross) i n the R O M collection from w o r k by Mackay (1969) in Q u é b e c . MORPHOLOGY Ironoquia, one of four North American limnephilid genera in which most abdominal gills o f the dorsal and ventral rows have more than four branches, is distinct from the others i n having more than two (usually five) major setae along the ventral edge of the middle and hind femora (A). M a n y metanotal setae arise from the integument between the primary sclerites (B). Length of larva up to 22 m m . CASE

Two types of larval case are known. I n I . punctatissima

and /. lyrata cases are

made o f bark and leaves, curved but little tapered (C); the case of I . parvula

is made of

sand grains (Flint 1960, fig. 48). Length of larval case up to 27 m m . B I O L O G Y A l t h o u g h North American larvae of the subfamily Dicosmoecinae are largely restricted to cool, running waters, species o f Ironoquia are the sole exception, l i v ing i n temporary pools and streams (Ross 1944; Flint 1958, 1960; Wiggins 1973a); these habitats are characterized by extremes of temperature and by a drought period of several months. Observations by Flint (1958) and Williams and Williams (1975) have demonstrated that larvae avoid drought by aestivating i n leaf litter around the margin of the receding water from late spring until pupation in early autumn. But sexually mature females o f I . lyrata emerged in June from larvae reared i n Q u é b e c by Mackay (1969), and there was no evidence of autumn activity by adults around the temporary stream habitat. Filamentous algae and vascular plant pieces were the dominant items in guts of larvae (3) we examined. R E M A R K S Taxonomy o f Ironoquia adults has been reviewed by Schmid (1951). Species have been assigned to Caborius i n the past.

Ironoquia sp. (Missouri, Franklin Co., 1 M a y 1961, R O M ) A, larva, lateral x8, middle femur enlarged; B, head and thorax, dorsal, detail of mesonotum; c, case x5 324

Limnephilidae: Ironoquia 20.24

325

20.25

Genus

Lenarchus

D I S T R I B U T I O N AND S P E C I E S Species of Lenarchus are widely distributed throughout the northern part of the Holarctic region. O f nine species k n o w n in North America, most are western and occur at higher elevations from Alaska to California; eastern species have been recorded from Minnesota to Q u é b e c and Massachusetts. Larvae were identified for Lenarchus from material of L . vastus (Hagen) we associated from Oregon and o f L . rho ( M i l n e ) from British Columbia (Wiggins 1977). Larvae described as L i m n e p h i l i n i 1 by Flint (1960) are probably of this genus. M O R P H O L O G Y Lenarchus is one of the few North American limnephilid genera i n which most abdominal gills of the dorsal and ventral rows have more than four branches. Larvae o f Lenarchus can be recognized because they have only two major setae on the ventral edge of the second and third femora (A), have all metanotal setae confined to the primary sclerites, and have separate mesonotal setal areas (B). Larvae have a dark brown head and thorax: in some species there is a light line running obliquely through the eyes (A, B), but not i n all. Length of larva up to 30 m m . C A S E Larval cases i n this genus are somewhat variable. Sometimes lengths of sedge leaves are arranged longitudinally (C). We have collected other larvae that probably are Lenarchus i n cases of irregular fragments of bark and leaves. Length of larval case up to 55 m m . B I O L O G Y These are species of standing waters - edges o f small lakes, ponds, marshes, and temporary pools, especially at higher elevations and latitudes. Winterbourn (1971a) found final-instar larvae o f L . vastus in Marion Lake, British Columbia, from October through A p r i l ; the larvae fed on organic sediments. Larvae of L . expansus M a r t y n o v occur in water-saturated tundra turf i n Alaska (MacLean and Pitelka 1971). R E M A R K S A taxonomic review of adults o f Lenarchus was provided by Schmid (1952b); a key to adults of North American species was given by Ross and Merkley (1952).

Lenarchus

vastus (Oregon, Jefferson Co., 17-18 June 1968, ROM)

A, larva, lateral x8; B, head and thorax, dorsal, detail of mesonotum; C, case, lateral x2 326

L i m n e p h i l i d a e : L e n a r c h u s 20.25

327

20.26

Genus L i m n e p h i l u s

D I S T R I B U T I O N AND S P E C I E S

Limnephilus

is a large genus of the Holarctic region.

Approximately 100 species are now known in North America and they occur over much o f the continent. Larval descriptions are available in the literature for only five species (Ross 1944; Flint 1960; N i m m o 1965); to date, we have associated material for 40 species. MORPHOLOGY

Colour patterns o f the head and thorax are of two basic types, and the

genus emerges from the key accordingly in two places. In one type, the dorsum of the head bears bands or patches of contrasting colour, and w i t h i n the narrowed posterior portion o f the frontoclypeal apotome are three light areas ( B ) - one along each side and one at the posterior extremity as i n Philarctus from Philarctus

(Fig. 2 0 . 3 0 B ) . A t least some Limnephilus

larvae differ

in having the two major setae of the mesofemur both situated at about the

midpoint of the femur (A) ( D . H . Smith, pers. comm.). In the second type of

Limnephilus

the head lacks bands or other well-defined areas of contrasting colour, and may have prominent spots, much as illustrated for L.frijole

Ross ( G ) ; i n some larvae the spots are

more numerous and tend to coalesce as i n Anabolia

bears several setae i n Limnephilus

(Fig. 20.3B). Mesonotal sa 1 usually

( B ) , but only a single seta in a few species (e.g. Johans-

son et al. 1991). Chloride epithelia are lacking dorsally from abdominal segments. Length o f larva up to 29 m m . CASE

The variety o f larval cases for Limnephilus

spp. known from our associations is

extremely broad: sand grains, pebbles (E), bark ( F ) , wood, and leaves arranged lengthwise (D) or transversely (C). Length of case up to 51 m m . BIOLOGY

Limnephilus

larvae are predominantly members of lentic communities in

ponds and marshes and along lake margins, although a few have been collected in streams and cold springs. Some species are typical of temporary pools and streams, marginal habitats they can exploit because diapause delays sexual maturity until late summer when the height of the drought is over; and also because after hatching from the eggs a few weeks later, larvae can remain within the thick gelatinous egg-matrix for several months until the basin is flooded again (Wiggins 1973a; Berté and Pritchard 1986). Limnephilus

larvae

feed mainly on detritus ( L l o y d 1921; Hodkinson 1975). REMARKS

Some progress has been made in distinguishing between larvae of

nephilus, Asynarchus,

and Philarctus,

Lim-

but the diagnostic characters offered are provisional

until more larvae of proven identity are available. Ross and M e r k l e y (1952) provided a key to males o f North American Limnephilus

species. Diagnostic characters for adults of a

number of western species were illustrated by N i m m o (1971). Limnephilus

indivisus (Ontario, Durham Co., M a y 1969, ROM)

A, larva, lateral x6, w i t h detail o f mesofemur; B , head and thorax, dorsal; C, case x3 L . submonilifer:

L . canadensis:

D, case x l . 7 E, case x2.4

L . ate reus: F, case L.frijole:

328

G , head, dorsal

Limnephilidae: Limnephilus 20.26

329

20.27

Genus

Nemotaulius

D I S T R I B U T I O N AND S P E C I E S Nemotaulius is a small Holarctic genus w i t h four species in eastern Asia, one in Europe, and one i n North America (Schmid 1952a). The single Nearctic species, N. host il is (Hagen), occurs across the continent from Alaska through Colorado to Newfoundland, south to the New England states and Pennsylvania. Larvae have been identified by L l o y d (1921) and Ross (1944) under Glyphotaelius, described by Flint (1960); we reared several series of larvae from Ontario.

and

M O R P H O L O G Y Nemotaulius larvae have distinctive head markings (B); on a base colour o f light brownish yellow a dark U-shaped band extends through each eye, and a median band extends through most of the length of the frontoclypeal apotome. The pronotum bears a central, transverse, dark band, and the anterior border is also dark; mesonotal sa 1 bears a stout single seta, sometimes w i t h small accessory setae. There are tiny spines on the head and pronotum. The venter of abdominal segment I has a group of prominent setae i n each of the three primary positions (D). The anal claw bears several accessory hooks (A). Length of larva up to 28 m m . C A S E From midsummer through autumn, Nemotaulius cases are constructed of pieces of leaves and twigs fastened more or less transversely; in the later instars rather large pieces are arranged i n dorsal and ventral series, giving the case a flattened appearance (C). But when collected in M a y and early June just before pupation, cases are of leaf pieces fastened longitudinally much as shown for Grammotaulius. Thus, it appears that case architecture is changed during the final instar and transitional cases are sometimes found (Flint 1960, f i g . 60); but evidently this does not always occur (Bernhardt 1966). Length of case up to 70 m m . B I O L O G Y Larvae are typical inhabitants of standing waters, especially small permanent ponds with a dense growth o f aquatic plants. The life cycle of N. hostilis was studied by Berté and Pritchard (1986).

Nemotaulius hostilis (New York, Tompkins Co., 12 Nov. 1957, ROM) A, larva, lateral x7, anal claw enlarged; B, head and thorax, dorsal; C, case, ventral x2; D, segment I , ventral 330

Limnephilidae: Nemotaulius 20.27

331

20.28 Genus Onocosmoecus D I S T R I B U T I O N A N D S P E C I E S This is a genus of North America and northeastern Asia. Two species are now recognized: O. unicolor Banks extends across North America from Newfoundland to Alaska south to California, and into eastern Asia; O. sequoiae Wiggins and Richardson is known from California, principally in the Sierra Nevada Mountains. The larva of O. unicolor has been described (Flint 1960, as O. quβdrinotatus Banks). We have many associated series of larvae.

Onocosmoecus larvae usually have a light median band on the proand mesonota and on the coronal suture of the head ( B ) , as do several other dicosmoecines. A row of 12-16 long, black, erect setae behind the anterior margin of the pronotum are of more uniform length than in Eocosmoecus, and the space between each seta of the mesal pair in this row and the adjacent lateral seta is less than the intervals between remaining setae ( B ) ; this character is valid in the last three instars at least. Metanotal setae are confined to the primary sclerites ( B ) . Abdominal segment V I bears 1-4 setae on each side of the mid-dorsal line; VII bears 1-5, usually 4, setae in this position; vin has a dorsal transverse row of 16-24 setae; segment ix bears 12-15 setae on the dorsal sclerite, and a row of 4-6 setae on each side ventrad from the sclerite ( D ) . Length of larva up to 25 mm. M O R P H O L O G Y

The larval case of O. unicolor is constructed of pieces of wood, bark, and leaves; the walls are thinner and more flexible than in Eocosmoecus frontalis, the species with which it is most likely to be confused. Prior to pupation, larvae construct a posterior sieve membrane of silk within the larval case but with more openings than in Eocosmoecus (Wiggins and Richardson 1989). Length of case up to 27 mm. C A S E

Larvae of O. unicolor live in slow flowing sections of cool rivers and streams, and also in the littoral zone of cool lakes, apparently with little preference in substrate since they occur on stony stream beds as well as organic sediments of lake margins. Larvae usually burrow into bottom materials for pupation, fixing the case to some larger object such as a rock; pupae were collected from June to the middle of October (Wiggins and Richardson 1987). Larvae are principally shredders; vascular plant pieces and filamentous algae together accounted for over 70% of the total gut content in specimens sampled, insect fragments, diatoms and fine particulate organic matter were present in smaller proportions in most guts. The life cycle of O. unicolor was studied in a British Columbia lake (Winterbourn 1971a), and in a stream system in Oregon (Wisseman and Anderson 1991). In Siberia larvae fed mainly on leaves and other allochthonous plant materials (Levanidova 1975, as O.flavus (Martynov)). Larvae develop from eggs deposited in September. B I O L O G Y

A taxonomic revision of Onocosmoecus (Wiggins and Richardson 1987) includes morphological, life history, and distributional information. R E M A R K S

Onocosmoecus unicolor (British Columbia, Marion Lake, 1969, R O M ) A , larva, lateral x6, middle tibia enlarged; B , head and thorax with detail of pronotum, dorsal; C , case x4; D , posterior abdominal segments, dorsal 332

Limnephilidae:

Onocosmoecus 20.28

333

20.29 Genus Phanocelia D I S T R I B U T I O N A N D S P E C I E S This is a monotypic genus confined to northern North America. A single species, P. canadensis (Banks), has been recorded from the Northwest Territories, Alberta, Manitoba, Quιbec, Nova Scotia, New Brunswick, and New Hampshire; sparse records for P. canadensis indicate that populations are highly localized. Information on the immature stages and biology was provided by Fairchild and Wiggins (1989). M O R P H O L O G Y Among larvae of North American Limnephilidae with single-filament gills ( A ) , Phanocelia is distinguished by short, wide mesonotal sclerites ( B ) , and by sparse setation and lightly sclerotized oblique bands on abdominal segment I ( A , D ) . Mesonotal setal areas 1, 2, and 3 are discrete, each represented by several setae ( B ) ; metanotal setae are confined to the three primary sclerites. Abdominal segment I bears approximately four setae at each side of the dorsal hump and also dorsad of each lateral hump, 1-2 setae ventrad of each lateral hump ( A ) , and 2-3 pairs of median ventral setae ( D ) . Abdominal gills are single ( A ) , chloride epithelia occur ventrally on abdominal segments I V through vil ( A ) , and forked lamellae are lacking; a linear band of fine setae extends across the posterior margin of segment vm (E). The claw of the anal proleg bears a single accessory hook; typically for the Chilostigmini, lateral sclerites of the anal prolegs bear stout, clear setae among longer black setae. In well-sclerotized larvae of P. canadensis, a pair of indistinct sclerous points may be visible at the posterodorsal margin of each lateral hump ( A ) ; these points could lead to confusion with Desmona, but they are not ring-like, and the short mesonotal sclerites are diagnostic for Phanocelia. Length of larva up to 12 mm. C A S E Larval cases of Phanocelia now known are distinctive in construction, with short pieces of sphagnum moss arranged transversely. Length of larval case up to 10 mm.

Larvae of P. canadensis are known yet from only a single site - a typical sphagnum bog pool in New Brunswick (Fairchild and Wiggins 1989); there they occurred in the floating fringe of moss around the open pool in water of pH 4.1. Whether they are restricted to sphagnum bog pools remains to be confirmed. Gut contents indicate that larvae feed on Sphagnum, insect larvae, and crustaceans. Larvae are univoltine, pupating and emerging in late summer. B I O L O G Y

Diagnostic characters for adults of P. canadensis have been summarized and illustrated by Nimmo (1971) and by Schmid (1980). A metamorphotype of this species from 1100 years B.P. has been documented from southern Ontario (Wiggins 1991). R E M A R K S

Phanocelia canadensis (New Brunswick, York Co., June 1985, R O M ) A , larva, lateral x l l , fore leg and abdominal segment I enlarged; B , head and thorax, dorsal; C , case, lateral x8; D , abdominal segment I, ventral; E , segments vm and I X , dorsal (From Canadian Entomologist) 334

Limnephilidae: Phanocelia 20.29

335

20.30

Genus

Philarctus

D I S T R I B U T I O N AND S P E C I E S This is a northern genus o f the Holarctic region, w i t h only one North American species, P. quae ris (Milne), which is known from Manitoba to Yukon and south to Colorado. Larvae associated in Manitoba have been described elsewhere (Wiggins 1963). M O R P H O L O G Y Three light-coloured areas on the narrowed portion of the frontoclypeus occur in Asynarchus, Clistoronia, and Limnephilus as well as in Philarctus. A provisional diagnostic character for Philarctus is found on the mesothoracic femur ( D . H . Smith, pers. comm.); the proximal of two major ventral setae is located about midway between the proximal end of the femur and the more distal seta (A). The accessory hook on the anal claw is single and lacks basal spines. Because of the close morphological similarity between larvae in Philarctus and Limnephilus, and of the large number of Limnephilus spp. for which larvae are not known, separation between the two genera is equivocal at this stage i n our knowledge. Length o f larva up to 18.5 m m . C A S E Larvae o f P. quae ris construct cylindrical cases of little taper or curvature. Usually cases are constructed of small rock pieces or sedge seeds, but frequently shells of snails and sphaeriid clams are used; entire cases of snail shells (C) are not uncommon in certain habitats. Length o f larval case up to 24 m m . B I O L O G Y We have found large populations o f P. quaeris in the small ponds and slow streams of the aspen parkland in southern Manitoba and Saskatchewan (Wiggins 1963). Pupation occurred in late June and early July, the larvae tending to congregate in the shallows before fastening their cases to some firm substrate. R E M A R K S Diagnostic characters for the male o f P. quaeris were provided by Ross and Merkley (1952) and by N i m m o (1971).

Philarctus quaeris (Manitoba, Erickson, 10 June 1962, ROM) A, larva, lateral x8, detail of mesofemur; B, head and thorax, dorsal; C, case, x5 336

Limnephilidae: Philarctus 20.30

337

20.31

Genus P h i l o c a s c a

D I S T R I B U T I O N AND S P E C I E S Seven species are now known in this rather obscure Nearctic genus; records extend from Alberta through Montana, Idaho, Washington, Oregon, and California. Larvae have been associated for two species, P. demita Ross and P. rivularis Wiggins (Wiggins and Anderson 1968); we have other series of larvae, almost certainly of this genus, but as yet not identified. M O R P H O L O G Y Larvae o f Philocasca are characterized by enlarged and flattened scale-hairs at least along the anterior edge of the pronotum (B, D, F). The dorsum of the head is flattened, very much so in some species, with a prominent carina (A, B), and usually bears some stout, flattened setae, too. The pronotum and usually some part of the head have a roughened texture; sclerotized parts are reddish brown in colour. Abdominal gills are single and arranged differently in at least some of the species; forked lamellae are lacking. Submental sclerites of the labium are fused (E). Length of larva up to 18 m m . C A S E A l l larval cases known are constructed of small rock fragments forming a cylinder of slight curvature; in the final instar, at least, cases have little or no taper, and the posterior opening is closed for all but a small central hole (c). Length of larval case up to 23 mm. B I O L O G Y Larvae now k n o w n indicate that Philocasca are characteristic of small, mountain spring streams; usually they are found in the stream in gravel beneath larger rocks. But larvae o f P. demita (F) have been collected only in soil and leaf litter up to 6 m from a spring stream in Oregon (Anderson 1967a; Wiggins and Anderson 1968). Larger instars o f P. demita were captured in pitfall traps sunk in the forest floor, smaller ones extracted with Berlese funnels from samples of leaf litter; no larvae o f P. demita were taken i n the nearby stream. Gut contents of the stream-dwelling P. rivularis (3) that we examined were largely vascular plant pieces. R E M A R K S A key to adults of Philocasca was given by Wiggins and Anderson (1968); one additional species was described from Alberta by N i m m o (1971). P. antennata (Banks), now assigned to this genus, was originally treated under Stenophylax (see Ross 1944: 299).

Philocasca rivularis (Oregon, Benton Co., 24 Sept. 1964, ROM) A, larva, lateral x l l ; B, head and thorax, anterolateral; C, case x6; D, anterior edge o f pronotum; E, maxillae and labium, ventral Philocasca demita (Oregon, Benton Co., ROM), F, head and thorax, anterolateral 338

Limnephilidae: Philocasca

20.31

339

20.32 Genus

Platycentropus

D I S T R I B U T I O N AND S P E C I E S amicus (Hagen) (syn. P. plectrus (Banks)); and P. radia tus Say (syn. within the area from Newfoundland

Platycentropus is a Nearctic genus of three species: P. Ross); P. indistinctus (Walker) (syn. P. frate mus P. maculipennis Kol.). Platycentropus spp. are known to Alberta, and south to Louisiana.

Larvae have been described for P. radiatus

(Flint I960; Ross 1944; L l o y d 1921 ); we

have associated material for all three species. M O R P H O L O G Y There seems to be no better diagnostic character for larvae of this genus than the unusually long prosternai horn, which in Platycentropus larvae extends ventrally to the mentum and the distal edges of the stipital sclerites ( D ) . Species differ in the markings on the dorsum of the head: P. indistinctus and P. radiatus have small, sparse muscle spots, as illustrated; muscle scars in P. amicus are more numerous, coalescing into a pattern similar to that illustrated for Anabolia. Abdominal segments have ventral and lateral chloride epithclia, but none dorsally; most gills o f the dorsal and ventral series are three-branched. Length of larva up to 22 m m . C A S E Cases for al 1 larvae we have collected are much the same as the one illustrated. Plant materials such as grasses and sedges are arranged transversely to produce a straight, fuzzy cylinder (C). Pupal cases of sand grains were attributed to P. indistinctus (Denning 1937), but all Platycentropus pupal cases known to me have been of the same construction as the larval cases. Length o f case up to 25 mm. B I O L O G Y Habitats o f Platycentropus larvae range from cool streams to warm ponds, and the two extremes were attributed to the same species, P. radiatus ( L l o y d 1921; Flint 1960). Species of this genus are among the most tolerant of all limnephilids to warm, quiet waters at the edges of slow streams, marshes, and lake margins where there are dense growths o f aquatic plants. N o Platycentropus species are k n o w n in temporary vernal pools, although cases o f Limnephilus indivis us, which is abundant in these habitats, are somewhat similar to Platycentropus cases. REMARKS

Platycentropus

Larvae illustrated were provided by O.S. Flint.

radiatus (New Hampshire, Crafton Co., 18 M a y 1957, U S N M )

A, larva, lateral x7; B, head and thorax, dorsal; C, case x4; D, head and prosternai horn, lateral 340

Limnephilidae: Platycentropus 20.32

341

20.33

Genus P s e u d o s t e n o p h y l a x

D I S T R I B U T I O N AND S P E C I E S Although primarily a genus of the Oriental region, Pseudostenophylax is sparingly represented in the Asian Palaearctic and in North America. I n the eastern half of the continent there are two species, P. uniformis (Betten) and P. sparsus (Banks); in the west, only P. edwardsi (Banks) is known, from British Columbia to California. Larvae of P. uniformis have been described (Flint 1957, 1960) and o f another species that is probably P. sparsus (Flint 1960, Pseudostenophylax species I ) ; we reared larvae for both. Larvae o f P. edwardsi have also been described (Wiggins and Anderson 1968); this is the species referred to L i m n e p h i l i d Genus A by Ross (1959) and Flint (1960). M O R P H O L O G Y The flat head of the western P. edwardsi ( D ) compared w i t h the normal head of the eastern larvae (A, B) introduces discordance in some characters of the genus; but in all species mesonotal setal areas are confluent through sal to sal to sa3, and there is a transverse band of setae between the metanotal sal sclerites. Sclerotized parts of the head and thorax are uniform reddish or yellowish brown, broken only by muscle scars. Abdominal gills are single. Length of larva up to 16 m m . C A S E Larval cases (c) are constructed mainly of small rock fragments, the exterior uniform i n outline. Length o f larval case up to 19 m m . B I O L O G Y Observations on the biology of P. uniformis have been made by Flint (1957) and Mackay (1969); the biology o f P. edwardsi was studied by Anderson (1974a). Generalizing, larvae live in cool spring runs or small streams of intermittent flow; they burrow into sand and gravel substrate as water recedes and presumably are protected there until the return of surface water. Larval development proceeds through autumn; winter is passed as final-instar larvae. R E M A R K S Species of this genus were treated for some time in the literature under Drusinus. Diagnostic characters of males of the two eastern species were provided by Ross (1944), where P. sparsus was treated under virginicus (see Flint 1966); characters for the male o f P. edwardsi were given by Denning (1956).

Pseudostenophylax sparsus (Ontario, A l g o n q u i n Pro v. Park, 1 June 1963, R O M ) A, larva, lateral x8; B, head and thorax, dorsal; C, case, lateral x7 P. edwardsi (Oregon, Benton County, 16 A p r i l 1964, R O M ) , D , head and thorax, anterolateral 342

Limnephilidae: Pseudostenophylax 20.33

343

20.34 Genus P s y c h o g l y p h a D I S T R I B U T I O N AND S P E C I E S Psychoglypha is an exclusively Nearctic genus in which 14 species are now recognized. One species, P. subborealis (Banks), cited in the literature as P. alaskensis (e.g. Schmid 1952c) until the genus was reviewed by Denning (1970), is transcontinental in a broad band extending roughly from Maine through southern Ontario and Michigan to Alaska, and south to California. A l l other species are k n o w n only i n western montane areas where as a generic group they are common and widespread. The larva of only P. subborealis

has been described (Flint 1960); we have associated

material for ten species. M O R P H O L O G Y Larvae of Psychoglypha spp. are sufficiently diverse morphologically that it is difficult to find congruent characters diagnostic for the genus. The two sclerites l y i n g close to the dorsal edge of the lateral hump of abdominal segment I (A) provide the only consistent character discovered thus far for all the larvae we have studied. Pigmentation in these sclerites is often little darker than the surrounding membrane, but they can be distinguished by a hard, shiny texture. A m o n g larvae now known, legs with alternate dark and light bands occur only in the transcontinental P. subborealis (A); in a few species stout spines and setae occur on the pronotum (B) and on the sclerite of segment IX and the lateral sclerites of the anal prolegs (D). Head markings usually consist of dark brown spots and blotches on a yellowish brown background, except i n P. be lia (Banks) where the head and legs are uniform dark brown. Abdominal gills are single. Length of larva up to 26 m m . CASE

Larval cases are usually constructed of small rock fragments and pieces of wood

combined into a straight tube o f little taper (C). Length of larval case up to 43 m m . B I O L O G Y Psychoglypha larvae occur in a wide range o f cool-water habitats, ranging from spring runs to larger streams and their marginal pools. In the autumn, as time for pupation approaches, larvae burrow into bottom gravel for metamorphosis. Observations on the biology o f P. subborealis in Oregon were contributed by Anderson (1967b); this species is believed to overwinter in the egg stage, or at least as first instars confined to the egg-matrix. Gut contents of larvae of P. subborealis were fine particulate detritus and animal fragments (Winterbourn 1971a). REMARKS

Taxonomy of Psychoglypha

adults was reviewed by Schmid (1952c).

Psychoglypha subborealis (Ontario, Durham Co., 12 Sept. 1962, ROM) A, larva, lateral x l 0, segment I enlarged; B, head and thorax, dorsal; C, case x5; D, segment IX and anal prolegs, dorsal; E, anal proleg, mesal 344

Limnephilidae: Psychoglypha 20.34

345

20.35

Genus P s y c h o r o n i a

D I S T R I B U T I O N A N D SPECIES

Psychoronia

is an obscure Nearctic genus with two

species recorded from New M e x i c o and Colorado. The taxonomic status of this genus is uncertain and its merger with Limnephilus

has been proposed; but what is now known of

larval morphology in both groups supports retention o f Psychoronia

as a distinct genus

(Wiggins 1975). Diagnostic characters for the genus were given by Ross (1959), based on an associated series of adults and larvae of P. costalis (Banks), here illustrated, from Colorado. M O R P H O L O G Y The larva of P. costalis is one of the few North American limnephilids in which most gills o f the dorsal and ventral series have four or more branches ( A ) ; i n the lateral series, gills are of single filaments and occur only on segment II and sometimes i l l . Except for a few muscle scars, the head is uniform brown. Neither of these character states occurs i n any Limnephilus now known. Mesonotal setal areas tend to be separate (B), but only the separation between sal and sa3 is distinct. On the metanotum a few setae arise between the primary sclerites (B). The dorsum and venter of abdominal segment I bear many setae; chloride epithelia are apparent only ventrally, and are somewhat shorter than in other genera ( A ) . Length of larva up to 12 m m . CASE

The case of P. costalis is made of rock fragments, for the most part coarse (C). The

posterior end of the case illustrated was closed off for pupation, as were all cases i n these series. Length o f larval case up to at least 12 m m . BIOLOGY

Larvae were collected in streams at high elevation; specimens of adults and

larvae have been taken from 8000 to 12000 ft (2400 to 3600 m). REMARKS

Through the assistance of D . E . Ruiter, we now have studied extensive series

of larvae and adults o f Psychoronia

costalis.

Psychoronia costalis (Colorado, Teller Co., 22 A u g . 1941, INHS) A, larva, lateral x l 5 ; B, head and thorax, dorsal; C, case x l l ; D, segments VIII and IX, dorsal 346

L i m n e p h i l i d a e : P s y c h o r o n i a 20.35

347

20.36 Genus P y c n o p s y c h e D I S T R I B U T I O N AND S P E C I E S Pycnopsyche is confined to North America, and comprises a dominant group of 15 species over much of the eastern half of the continent. Two species, P. subfasciata (Say) and P. guttifer (Walker), range to the Rocky Mountains, much farther westward than the others. Flint (1960) provided a key to larvae o f seven species of Pycnopsyche; ated larvae for six species.

we have associ-

M O R P H O L O G Y Pycnopsyche larvae have an elongate sclerite adjacent to the posterior edge o f the lateral hump (A). Distinction between larvae o f this genus and of Hydatophylax may be difficult because metanotal sal sclerites are close together in some species o f Pycnopsyche; diagnostic characters are given in the key. Usually the base colour of the head in Pycnopsyche is yellowish b r o w n w i t h darker spots and blotches. Sclerites of head and thorax are frequently beset with small spines, which in P. gentil is ( M c L . ) are quite stout; this species is also unusual in having a flattened head and in lacking a median dorsal hump on segment I. Gills are single. Length of larva up to 29 m m . C A S E Early instars of all species construct cases of plant materials, usually bark and twigs or leaf discs; during the terminal instar the leaf cases are usually converted to cases of w o o d (C) or rock fragments. Length o f larval case up to 59 m m . B I O L O G Y Larvae of most Pycnopsyche live in cool woodland streams and small rivers, largely in deciduous forest areas. The time of hatching coincides w i t h autumnal leaf fall in September and October, and the larvae are important detrital processors i n the autumnwinter stream community. The early instars of all species, with cases either of leaf discs or of bark and twigs, are found i n slow-flowing parts of the stream where leaves and organic detritus accumulate. After construction of the final-instar case, larvae pass a prepupal aestivation period o f 1-6 months either buried i n the stream gravel or with the case attached to the underside o f rocks and logs, the time and place characteristic of each species. Pupation and emergence occur between July and October. Pairs o f Pycnopsyche species commonly occur together i n the same stream, one species constructing a leaf case and the other a t w i g case (Cummins 1964; Mackay 1972). REMARKS

A review of adults of species o f Pycnopsyche

was provided by Betten

(1950).

Pycnopsyche guttifer (Ontario, Leeds Co., 16 M a y 1965, ROM) A, larva, lateral x6, segments I and IX enlarged; B, head and thorax, dorsal; C, case x3 348

Limnephilidae: Pycnopsyche 20.36

349

20.37

Genus

Sphagnophylax

D I S T R I B U T I O N AND S P E C I E S Sphagnophylax is a North American genus of one species, S. meiops Wiggins and Winchester (1984), known only from the Arctic tundra o f Yukon and the adjacent Northwest Territories. M O R P H O L O G Y Larvae of Sphagnophylax have stout abdominal gills of three filaments, reduced to one and two filaments on posterior segments (A); chloride epithelia occur only ventrally; a single seta occurs at each mesonotal sal position (B). This combination o f characters distinguishes larvae of Sphagnophylax from those o f several other genera having abdominal gills w i t h one to three filaments. Abdominal segment I bears setae at all three primary setal areas, both dorsally and ventrally (E); a posterodorsal transverse row of about 12 setae occurs on VIII, and the dorsal sclerite o f IX bears four long setae w i t h one or two short setae between each pair (F). Sclerites of the anal proleg lack short stout setae, and the claw o f the anal proleg bears two accessory hooks. The head is uniform light brown w i t h dark spots at muscle scars (B); the ventral apotome is short, w i t h the genae contiguous mesally over the posterior half o f the gular area. The maxillary lobes are erect and rod-like (D). The pronotum lacks stout setae along the anterior border. Legs have no more than two large femoral setae, and lack a setal brush on the trochanter (A). Length of larva up to 14 m m . C A S E Larval cases o f Splmgnophylax are constructed of pieces of sedge leaves arranged lengthwise (C). Length o f case up to 17 m m . B I O L O G Y Larvae o f S. meiops are known only in Arctic tundra pools overlying permafrost; a population was studied near Tuktoyaktuk, Northwest Territories ( 6 9 ° 2 9 N x 1 3 2 ° 3 5 ' W ) (Winchester et al. 1993). The pool held surface water for about two weeks i n June after spring thaw and then receded into water-saturated moss and other organic material where larvae completed feeding, growth, and metamorphosis. The species is univoltine; adults are brachypterous, emerging mainly in July and evidently f l y rarely, i f at all. Eggs are deposited i n the wet Sphagnum moss o f the pool basin, and larvae reach instars III to v before passing the winter of some eight months encased i n ice in the water-saturated organic materials o f the pool basin. /

R E M A R K S N o close relatives of this genus are known; evidence for assignment to the tribe L i m n e p h i l i n i was outlined by Winchester et al. (1993). Sphagnophylax is a most unusual genus; it is both a phylogenetic and geographic relict, and on present evidence is the only genus of Trichoptera restricted to Nearctic Beringia (Wiggins and Parker, i n press).

Sphagnophylax meiops (Northwest Territories, nr. Tuktoyaktuk, June 1983, ROM) A, larva, lateral x9 w i t h detail of anal proleg; B, head and thorax, dorsal; C, case x5; D , head, ventral, maxilla and labial palp enlarged; E, abdominal segment I , dorsal and ventral; F, abdominal segments VIII and IX, dorsal (From Canadian Journal o f Zoology) 350

Limnephilidae: Sphagnophylax 20.37

351

21 Family Molannidae

This is a small but distinctive family of the Holarctic and Oriental faunal regions. Two genera are represented in the Nearctic fauna, with only seven species. M o l a n n i d larvae can be recognized immediately in the field by their flattened cases of small rock fragments, which have lateral flanges and a hood over the anterior opening. Since the cases blend with the surrounding sand substrate and no part of the insect is visible from above, larvae are usually detected only when they move their case. Similar flanged cases are made by some species in the leptocerid genus Ce racle a, but they are stout, convex cases i n which the posterior opening is reduced with silk to a small regular hole; molannid cases are more fragile and the posterior opening is flattened, ragged, and ill-defined, but not reduced with silk (Fig. 21.1c). Morphologically, molannid larvae are distinguished by aberrant hind tarsal claws o f two types, as described under the generic headings; the function of these unusual claws is unknown. The hind legs are substantially longer than the others, and the tibiae secondarily subdivided near the middle; the fore tibia is extended distoventrally as a long process with a single spur at the apex. The mesonotum bears a lightly sclerotized plate, divided along the median line, i n some species completely but i n others only through the anterior half to intersect w i t h a transverse suture (Fig. 21.2B). Primary setal areas are represented on the metanotum, but sclerites are absent. Humps on abdominal segment I are prominent; gills are present on several segments. The lateral fringe is well developed, and forked lamellae are confined to segment v m . Chloride epithelia are present on the abdomen but difficult to distinguish; i n Molanna blenda they occur as anterolateral oval areas immediately dorsal to the lateral fringe on segments III to VII. Most larvae live in lakes, ponds, and areas o f slow current in rivers, but Molanna blenda occurs i n cold springs. The insects live on sand and m u d substrates, where they are omnivorous i n feeding (Balduf 1939; Lepneva 1964). M o l a n n i d larvae bury themselves in the substrate before pupation. As i n the Leptoceridae, the larval exuviae are ejected through the posterior opening of the case shortly after larval-pupal ecdysis.

352

21 Family Molannidae Key to Genera* 1

Tarsal claw of hind leg modified into setose lobe, much shorter than tarsus (Fig. 21.1 A ) Widely distributed through the east and westward to Colorado, Yukon, and Alaska 21.1 Molanna Tarsal claw of hind leg modified into slender filament of about same length as tarsus (Fig. 21.2A). Alaska and Yukon, rarely eastward to northern Ontario 21.2 Molannodes

*See qualifications under Use of Keys, p. 7. 353

21.1

Genus

Molanna

D I S T R I B U T I O N AND S P E C I E S This genus, confined to the Holarctic and Oriental regions, comprises six species in North America. A l l occur within the eastern half of the continent, fewer species to the south than the north, but M. flavicomis Banks extends west to Colorado and Alaska. Diagnoses were given for larvae of three species by Sherberger and Wallace (1971): M. tryphena Betten, M. blenda Sibley, and M. uniophila Vorhies. Other data were contributed for M. blenda by Sibley (1926) and Ross (1944); for M. flavicomis Banks by Neave (1933) and Denning (1937): for M. tryphena by Betten (1902, as M . cinerea); and for M. uniophila by Vorhies (1909) and Ross (1944). We have associated material for six species. M O R P H O L O G Y Molanna larvae are readily distinguished by the short, stout claw of the hind leg (A); the basal seta of the claw originates from about its centre, and the upper surface of the claw bears short setae. Larvae of all the Nearctic species have contrasting dark bands on the dorsal ecdysial lines of the head. I n some species, although not in the one illustrated, the mesonotal sclerite is subdivided by a transverse suture (Ross 1944, fig. 709). Most abdominal gills have 2-4 filaments. Length o f larva up to 19 m m . C A S E Molanna cases (C) are made of rock fragments, sometimes w i t h organic materials, and have a prominent lateral flange and anterior hood that conceals the larva completely. Larvae o f some species incorporate a marginal row of relatively larger pieces into their cases (Sherberger and Wallace 1971). Length of larval case up to 27 m m . B I O L O G Y Larvae live in lakes or the slower currents of rivers and streams, and inhabit the sand and mud substrates of these sites. Molanna flavicomis was found to 20 m in the deepest parts of Lake Winnipeg (Neave 1933); one species, M. blenda, is confined to small, cold springs. Diatoms, filamentous algae, vascular plant tissue, and small invertebrates are reported as the major items ingested (Neave 1933; Sibley 1926; Solem 1970). R E M A R K S Diagnostic characters of Molanna flavicomis, illustrated here, have not previously been available in the literature; the larva is distinguished from all other North American species by a long, stout spur at the base of each anal proleg (E).

Molanna flavicomis (Manitoba, Minnedosa, 10 June 1962, ROM) A, larva, lateral x7, w i t h portions of leg segments enlarged; B, head and thorax, dorsal; C, case, ventral x4.5, posterior opening i n dorsal view; D, head, ventral; E, anal prolegs, dorsal 354

Molannidae: Molanna

21.1

355

21.2 Genus Molannodes D I S T R I B U T I O N A N D S P E C I E S The species M. tinctus Zett. occurs across northern Europe and Asia into Alaska, the Yukon, and sporadically in Saskatchewan and northern Ontario. The North American populations, originally described as M. bergi Ross (1952), were found to be conspecific with the Eurasian populations (Wiggins 1968). Another species is known from Japan (Fuller and Wiggins 1987) R O M field parties have collected several series of Molannodes larvae in Yukon and Alaska, but no positive association has been established with adults in North America.

In general features Molannodes larvae are similar to those of Molanna but are distinguished by the slender filament-like tarsal claw of the hind leg ( A ) ; apparently, early instars of at least some Molanna species have a similar slender filament. The basal seta of the claw arises at about its mid-point, but is very long. The dorsum of the head is uniformly dark, and the mesonotal plate is subdivided by a transverse suture as in some species of Molanna. Abdominal gills are mostly single. Length of larva up to 12.5 mm. M O R P H O L O G Y

Molannodes larvae incorporate more pieces of plant detritus into their cases ( C ) than do Molanna, and sometimes build a case entirely of detritus (Lepneva 1966). The lateral flanges and anterior hood are smaller in Molannodes cases. Length of larval case up to 20 mm. C A S E

Larvae live in sites similar to those frequented by Molanna. Insects and vascular plant tissue are the food of this species (Siltala 1907b). B I O L O G Y

The illustration was prepared from larvae obtained from the Zoological Institute, Russian Academy of Sciences, loaned through the cooperation of L. Zhiltzova. R E M A R K S

Molannodes tinctus (Russia, River Belaja, 20 Oct. 1949, Russian Acad. Sci.) A , larva, lateral xl2, hind tarsus enlarged; B , head and thorax, dorsal; C , case, ventral x6 356

Molannidae: Molannodes 21.2

357

This page intentionally left blank

22 Family Odontoceridae

This is a small family represented in most faunal regions. Thirteen species are known north of Mexico representing six genera, three of which are monotypic; apart from some Psilotreta, the North American species tend to be local and obscure. These can be interpreted as characteristics of a senescent group, once widespread but with the passing of time increasingly confined in habitat and distribution. Morphologically, there is such marked diversity among larvae of the North American genera that it is difficult to find congruent diagnostic characters at the family level. The mesonotal plates are heavily sclerotized, separated in most genera only by a median ecdysial line, but in Marilia each plate is subdivided into three sclerites. Metanotal sclerites range from the condition in Namamyia and Nerophilus where all are small and separate with sal in two parts; through larger, separate sclerites in Pseudogoera and Marilia; to the condition in Parthina and Psilotreta where the sal and sal pairs are fused into transverse plates. The ventral apotome of the head is also diverse, ranging from a convex sclerite completely separating the genae in Marilia and Parthina; through a long, narrow sclerite in Namamyia; to a short sclerite partially separating the genae in Nerophilus and Psilotreta; to the minute ventral apotome in Pseudogoera. Large prosternai sclerites are present in all genera except Parthina; some sclerotization of the mesosternum is also evident. Tarsi of the middle and hind legs have a small distal cluster of spines (Fig. 22.4A). Abdominal gill filaments are usually short, thin, and always in tufts. The anal prolegs usually lack curved accessory hooks, but tend to have straight spines on both the claw and the lateral sclerite; and the lateral sclerite is often extended ventrally. The lateral fringe is variously developed; forked lamellae are usually confined to segment V I I I , but in Pseudogoera are extended anteriorly at least to segment IV. For the most part North American odontocerid larvae are burrowers in gravel, sand, and silt deposits of running waters, and are not usually encountered unless these deposits are searched. The eastern genus Psilotreta might appear to be an exception because the larvae pupate gregariously in layers on the underside of rocks, but observations indicate that all instars burrow. Larvae of the European Odontocerum albicorne (Scop.), found

359

22 Family Odontoceridae under stones during the day, were active at night, scavenging plant and animal materials (Elliott 1970). Case-making behaviour in the Odontoceridae is different from that in other families i n a way that is probably related to the burrowing habit. Examination reveals that cases in most trichopteran families are held together by means o f some silk around the edges o f component pieces i n a kind o f mortar j o i n t , and by a continuous lining sheet o f silk around the whole interior o f the case. Odontocerid cases appear to be constructed with larger mortar joints but w i t h no internal lining o f silk; instead, most have interior silken brace bands between adjacent rock pieces (Fig. 22.6F). This method o f construction is evident in cases of Psilotreta,

Namamyia,

and Pseudogoera,

where larger rock fragments are combined

w i t h small pieces; on the inside o f these cases it can also be seen that small rock pieces are incorporated into the silken mortar joints almost as a mosaic between larger pieces (Fig. 22.6F). The remarkable resistance o f Psilotreta

cases to crushing between one's fingers

suggests that these modifications i n case construction are effective safeguards against case breakage i n shifting gravel deposits o f running waters. Sieve-like closure o f the posterior opening of their cases w i t h rock fragments by larvae o f Psilotreta

and Namamyia

also

seems to contribute to the solidity o f the case. Larvae making cases o f smaller and more uniform rock fragments, such as Nerophilus

and Parthina

in North America, are more

characteristic o f fine-particle deposits i n small streams; these cases do not seem to be unusually resistant to breakage. Larvae o f Parthina

cover the external surface o f their

cases w i t h a thin layer o f silk. Thus, the North American odontocerids reveal examples o f somewhat different case-making behaviour; and this appears to have furthered diversification o f habitats to a burrowing mode o f life. Perhaps also related to a burrowing habit is the tendency for odontocerid larvae to have sclerotized sternal plates on the first and second thoracic segments. Absence o f a complete silk lining in odontocerid cases is possibly correlated w i t h the broadly pointed anal claws of the larvae and w i t h their tendency to bear straight accessory spines. Larvae in other families constructing portable cases generally have acutely pointed anal claws w i t h curved accessory hooks. I infer that the odontocerid prolegs anchor the larva more effectively i n its case when the interior is not lined w i t h silk. Transverse discontinuities i n the arrangement o f rock pieces in some odontocerid cases (Fig. 22.1c) are also an unusual feature o f this family. Gut contents from larvae o f North American genera indicate that the family is largely omnivorous; insect parts are found in the guts w i t h some consistency, but it is not clear whether this reflects predacious feeding or scavenging. The wide range of instars represented i n single collections o f larvae throughout our material suggests that life cycles o f more than one year are the general condition. Two subfamilies are recognized i n North America. The Pseudogoerinae comprise only the unusual genus Pseudogoera

(Wallace and Ross 1971). A l l other genera remain i n the

Odontocerinae. Larval morphology has been little used i n assessing relationships within the Odontoceridae, but the diversity among larvae o f the North American genera indicates that it has much information to offer.

360

22 F a m i l y O d o n t o c e r i d a e K e y to G e n e r a * 1

Fore tibia broad, approximately four times as long as tarsus, single apical tibial spur expanded and blade-like (Fig. 22.5A). Southeastern (subfamily Pseudogoerinae) 22.5 Pseudogoera Fore tibia normal, approximately same length as tarsus, apical spurs slender and not expanded ( F i g . 22.1A)

2

3

(subfamily Odontocerinae) 2

(1) Anterolateral corner o f pronotum produced into sharp point (Fig. 22.6A, B)

3

Anterolateral corner of pronotum rounded and not pointed (Fig. 22.2A)

4

(2) Ventral apotome o f head long, separating genae completely (Fig. 22 AD);

claw

of anal proleg stout, claw and lateral sclerite armed w i t h straight spines (Fig. 22.4A). Western montane areas

22.4 Parthina

Ventral apotome o f head short, genae largely contiguous along median ventral ecdysial line (Fig. 22.6c); claw o f anal proleg slender, claw and lateral sclerite without spines (Fig. 22.6A). Eastern half of continent 4

22.6 Psilotreta

(2) Each mesonotal plate subdivided into three sclerites, metanotal sal sclerites large and rectangular, closely appressed along mid-dorsal line (Fig. 22.1A, B ) Widespread

22.1 M a r i l i a

Each mesonotal plate undivided, metanotal sal sclerites small, ovate, and 5

widely separated across mid-dorsal line (Fig. 22.2A, B) 5

(4) Venter abdominal segment I w i t h t w o clusters of g i l l filaments and two pairs of setae ( F i g . 22.3E). Western

22.3 Nerophilus

Venter segment I without gills but w i t h many setae (Fig. 22.2E). Western 22.2 N a m a m y i a

*See qualifications under Use of Keys, p. 7. 361

22.1

Genus M a r i l i a

D I S T R I B U T I O N A N D S P E C I E S Apart from two species known to occur north of M e x i c o , Marilia is a Neotropical genus in the New World; species assigned to Marilia are also recorded from the Oriental and Australian regions. Marilia nobsca M i l n e is known from Texas; and M. flexuosa Ulmer is recorded from California, Arizona, Texas, and Arkansas. We have associated larvae and adults for both, and also for a population from southeastern Ontario (Hastings Co.) similar to M. flexuosa. Diagnostic larval characters for the genus were given by Ross (1959). M O R P H O L O G Y Marilia larvae are the only North American odontocerids i n which each mesonotal plate is subdivided into three sclerites (A, B ) . Metanotal sal sclerites are separated mesally and posterior to each is a transverse line of setae i n the sal position. The head bears one or t w o ridges along each side, and the genae are entirely separated by the ventral apotome ( D ) . The abdomen lacks a lateral fringe and the lateral sclerite of the anal proleg is edged mesally w i t h stout spines ( A ) . Length of larva up to 9.5 m m for M. flexuosa; up to 17.5 m m for M. nobsca. C A S E Larval cases ( c ) are made o f sand grains, smoothly contoured, curved, and tapered posteriorly. The silken membrane reducing the size of the posterior opening has an oval hole at the dorsal edge. On the case illustrated, the arrow indicates a discontinuity in the addition o f new pieces, a condition often found in odontocerid cases. Length o f larval case up to 10.5 m m for M. flexuosa; up to 24 m m for M. nobsca. BIOLOGY Our collections o f Marilia larvae have been taken in small streams in arid areas o f the southwest and in a shallow river 50 m or so wide i n Ontario; the Ontario larvae o f Marilia were taken literally i n the same sample o f bottom gravel as specimens o f Psilotreta. Gut contents of both M. flexuosa and nobsca (three larvae of each species) were largely arthropods, but there were also filamentous algae and pieces of vascular plants. REMARKS

Diagnostic characters for the male o f M. flexuosa

were given by Denning

(1956).

Marilia flexuosa (Arizona, Cochise Co., 25 June 1966, ROM; A , larva, lateral x l 7 , anal proleg enlarged; B , head and thorax, dorsal; c, case, lateral x l 2 , arrow indicates discontinuity; D , head, ventral 362

Odontoceridae: Marilia 22.1

363

22.2 Genus N a m a m y i a D I S T R I B U T I O N AND S P E C I E S The genus Namamyia occurs only in western North America, where a single species, N. plutonis Banks, is recorded from Oregon and California. No positive larval association has been established for this genus. But with generic identity of all other Nearctic odontocerid larvae now known, the one type still outstanding, here illustrated, is almost certain to be Namamyia; this is probably the larva referred to Odontocerid Genus A by Ross (1959). We have collected several series of larvae in California and Oregon and have adults from the Oregon locality (in Benton Co.) as well. M O R P H O L O G Y Larvae of Namamyia as well as Nerophilus are distinctive among North American odontocerids in having small, separate metanotal sclerites in the sal position and a second group of setae in sal ( B ) . But in Namamyia abdominal segment I is heavily setate dorsal 1 y and ventrally, and lacks ventral gills (A, E ) . The head in Namamyia is pebbled in texture dorsal ly, bears a ridge along each side ( B ) , and has a slender ventral apotome separating the genae entirely ( F ) . The prosternum bears a pair of heavily sclerotized plates ( D ) , shorter than in Pseudogoera but subdivided mes all y as in Nerophilus. The lateral fringe of the abdomen is well developed (A), and forked lamellae are confined to segment vill. Length of larva up to 20 mm. C A S E The larval case ( C ) is made of small rock fragments and is somewhat coarser textured than that of Nerophilus. The case is curved, and in some examples more tapered than illustrated. The sieve-like closure of the posterior end gives the impression of a pupal case, but cases of subterminal instars in our collections are similar in this detail; case-building behaviour is therefore different from that in Nerophilus. Length of larval case up to 30 mm. B I O L O G Y Larvae we have collected were living in gravel substrates of small, cool streams. Gut contents of larvae (3) examined were largely pieces of vascular plants with some fine particulate organic material. R E M ARKS (1968b).

Diagnostic characters for adults of N. plutonis were summarized by Schmid

Namamyia prob. plutonis (?) (California, Shasta Co., 29 July 1950, R O M ) A , larva, lateral x7, anal claw enlarged; B , head and thorax, dorsal ; C , case, lateral x5; D , prothorax, ventral; E , abdominal segment I, ventral; F, head, ventral 364

Odontoceridae: N a m a m y i a

22.2

365

22.3

Genus

Nerophilus

D I S T R I B U T I O N AND S P E C I E S

This is another genus endemic to mountainous parts

o f western North America; a single species, N. californiens

(Hagen), is recorded from Cal-

ifornia and Oregon. The larva o f N. californiens

was identified from material we reared in Oregon (Wiggins

1977). M O R P H O L O G Y Nerophilus larvae are generally similar to those o f Namamyia, but can be distinguished by the presence o f two g i l l tufts on the venter o f abdominal segment I , and by the much sparser setation on both dorsum and venter o f abdominal segment I (A, E). Another character distinctive for Nerophilus is the fringe o f short setae along the posterior margin o f the ventral extension o f the anal proleg's lateral sclerite (F); the anal claw bears stout, straight spines dorsally (A). The head and pronotum have a dark median band. The ventral apotome o f the head separates the genae only partially (D). A heavily sclerotized prosternai plate is present, divided along the mid-ventral line as in Namamyia. The lateral fringe o f the abdomen is well developed (A). Length o f larva up to 16.5 m m . C A S E Larval cases i n Nerophilus (C) are built o f sand grains, smoothly textured, curved and tapered. The posterior end o f the case is evidently left entirely open until some time during the final instar, when i t is reduced to the curved central opening illustrated. Length o f larval case up to 25 m m . BIOLOGY Larvae we collected in several Oregon localities were all l i v i n g in sand and silt deposits of small, cool streams. Guts o f larvae (3) we examined contained vascular plant pieces and fine organic particles, but each one also contained arthropod remains. Diagnostic characters for the male o f N. californiens

REMARKS

were given by Den-

ning (1956).

Nerophilus

californiens

(Oregon, L i n c o l n Co., 15 A p r i l 1964, ROM)

A, larva, lateral x l O , anal claw enlarged; B, head and thorax, dorsal; C, case, lateral x8; D, head, ventral; E, abdominal segment I , ventral; F, segment IX and anal proleg, lateral 366

Odontoceridae: Nerophilus 22.3

367

22.4 Genus P a r t h i n a D I S T R I B U T I O N AND S P E C I E S

Parthina are known only from western N o r t h Amer-

ica: P. linea Denning from California, Arizona, and Oregon; and P. vierra Denning from California. Larvae o f Parthina

have been identified from associated series collected for both spe-

cies (Wiggins 1977). M O R P H O L O G Y Larvae o f Parthina are similar to those of the eastern genus Psilotreta, but can be distinguished by the broad anal claw; both claw and lateral sclerite are beset w i t h stout spines (A). O n the head the genae are separated almost entirely by the ventral apotome (D), much as in Marilia. The prothorax lacks a transverse ventral sclerite, but the notum is extended into a prominent anterolateral point at each side (A). Metanotal sal and sal sclerites are each fused with their opposite members into single transverse sclerites (B). The abdomen is without a lateral fringe (A), and forked lamellae are confined to segment vill. Length o f larva up to 8.5 m m . The larva o f P. vierra differs from that o f P. linea (illustrated) in having a crenate anterior pronotal margin and prominent extensions on each side o f the head. C A S E Larval cases i n Parthina (C) are made o f sand grains, but are unique among North American odontocerids in having a layer of silk applied to the exterior, giving a varnished aspect to the case. Evidently the posterior opening o f the case is not restricted until the final instar, when a s mal 1 rock fragment is fastened to a silken tab at one side (C); a closure membrane is ultimately spun across the entire opening. Length of larval case up to 10 m m . BIOLOGY

Larvae o f Parthina

occur in small, cold springs in sand and gravel or on

rocks or moss. Contents examined from guts o f larvae (3) were mostly vascular plant pieces and fine organic particles, with some filamentous algae. REMARKS

Parthina

Diagnostic characters for adults were given by Denning (1956, 1973).

linea (California, Nevada Co., 19 July 1966, ROM)

A, larva, lateral x l 3 , middle tarsus, claw and anal proleg enlarged; B, head and thorax, dorsal; c, case, lateral x l O ; D, head, ventral 368

O d o n t o c e r i d a e : P a r t h i n a 22.4

369

22.5

Genus

Pseudogoera

D I S T R I B U T I O N AND S P E C I E S The rather unusual species Pseudogoera singularis Carpenter, the sole member o f this genus, has been found only in the southeastern United States (Georgia, North and South Carolina). Originally assigned to the Goeridae on the basis o f the male, and long an enigma (Flint 1966), P. singularis was finally shown to be an aberrant member o f the Odontoceridae when identity of its larval and pupal stages was established (Wallace and Ross 1971). We collected larvae i n North Carolina. M O R P H O L O G Y The larva can be distinguished by the enlarged tibia o f the fore leg (A), which is about four times as long as the tarsus and unusually wide; the movable apical tibial spur is expanded into a blade-like structure w i t h a terminal point; the legs are unusually long. The head is elongate, and the anterior ventral apotome is very small ( E ) . The prothorax bears a sclerotized sternal plate ( D ) that is not subdivided along the mid-ventral line as in Namamyia and Nerophilus, and the fore trochantin is reduced; the mesosternum also bears a sclerotized plate. Metanotal setal areas are located on large discrete sclerites (B). A b d o m i n a l segment I bears a pair o f large setal patches ventrally (A), and the lateral fringe of the abdomen is lacking; tiny forked lamellae occur on segment v n i but extend anteriorly at least to IV. The lateral sclerite o f each anal proleg is heavily spined (F). Length o f larva up to 8.5 m m . C A S E The larval case o f P. singularis (C) is constructed of rock fragments, curved, and tapered. The posterior opening is reduced w i t h silk to a rosette shape. Length o f larval case up to 10 m m . BIOLOGY Larvae live i n small, cool streams, where they are most commonly found associated w i t h small waterfalls (Wallace and Ross 1971); generally larvae are found in moss growing on rocks, often under ledges of the waterfalls. Gut contents o f larvae (2) we examined were fine organic particles and arthropod parts.

Pseudogoera singularis (North Carolina, Great Smoky Mountains Nat. Park, 21 M a y 1970, ROM 700366) A, larva, lateral x l 8 , fore leg enlarged; B, head and thorax, dorsal; C, case, lateral x9; D , pro- and mesothorax, ventral; E, head, ventral; F, segment IX and anal prolegs, dorsal 370

Odontoceridae: Pseudogoera 22.5

371

22.6

Genus P s i l o t r e t a

D I S T R I B U T I O N A N D S P E C I E S Psilotreta is k n o w n from the Nearctic and Oriental regions. Six species are recorded from North America, collectively from the area bounded by Tennessee and North Carolina to New Hampshire and Q u é b e c , through Ontario to Wisconsin. Larval stages have been characterized for all of the Nearctic species (Parker and W i g gins 1987). M O R P H O L O G Y Larvae o f Psilotreta are generally similar to those o f the western genus Parthina; but the more slender claw o f the anal proleg and the absence of stout spines w i l l distinguish Psilotreta ( A ) , as w i l l the small ventral apotome separating the genae for only a short distance (C). The anterolateral pronotal margins are sharply pointed, and the presternum bears a short transverse sclerite; much of the mesosternum is also sclerotized; metanotal sal and sal sclerites are fused to form two transverse plates ( B ) . The trochanters are subdivided into four sclerites ( E ) . The abdomen bears a lateral fringe and a few forked lamellae occur on v m ( A ) . Length of larva up to 15 m m . C A S E Psilotreta cases ( F ) are curved, tapered, and constructed o f rather coarse fragments of rock; they are exceedingly sturdy and are more resistant to crushing than cases of any other North American caddisfly that we have found. As discussed i n the introduction to the Odontoceridae, sturdiness appears to be gained by reinforcing the depressions between larger pieces i n the interior wall w i t h small rock fragments, and by strengthening interior connections between pieces w i t h bands of silk ( F ) . The posterior opening is reduced w i t h rock and silk to only a small eccentric hole. Length o f larval case up to 20 m m . BIOLOGY Larvae live i n riffle areas o f streams both large and small, where they crawl over bottom substrates or burrow i n them; similar observations were reported by Mackay (1969). Food is largely plant materials: algae were the main items ingested by P. indecisa (Coffman et al. 1971); gut contents from larvae (3) we examined were mainly pieces o f vascular plants and fine organic particles. L l o y d (1921) noted the marked gregarious behaviour that causes Psilotreta larvae to fasten their cases for pupation in dense layers on the underside of rocks: no comparable behaviour is k n o w n in any other North American odontocerid. REMARKS

Taxonomy, distribution, and phylogeny of all stages of the Nearctic species

were studied by Parker and Wiggins (1987).

Psilotreta rufa (Virginia, Shenandoah Nat. Park, 18 Sept. 1958, R O M ) A , larva, lateral x l 3 , anal proleg enlarged; B , head and thorax, dorsal; c , head, ventral; D , mandibles, ventral; E , right mesotrochanter, posterior and dorsal; F, case, lateral x7, portion o f case showing construction of interior wall and two rock fragments with silken cross braces enlarged 372

O d o n t o c e r i d a e : P s i l o t r e t a 22.6

373

23 Family Phryganeidae

The Phryganeidae are a family o f the Holarctic and Oriental regions, numbering about 75 species i n 15 genera. For the most part, they are insects of northerly latitudes or high elevations; in N o r t h America there are 10 genera w i t h 28 species. Larvae of different genera live i n a wide range o f aquatic habitats: spring streams, marshes, lakes to depths of 100 m , and temporary vernal pools. Available evidence suggests that overall the larvae are omnivorous, although some are largely predacious for at least part o f their life cycle. Larvae are large, often over 40 m m long, but morphologically homogeneous. Intersegmental constrictions are more prominent, the larvae are more slender and agile than in other case-making families, and the head is more prognathous; these are characteristics conveyed in the term suberuciform

applied to the Phryganeidae. The head and pronotum

in almost all species are conspicuously marked w i t h dark bands on a yellow background; genera and often species in the same genus differ in these markings. A prominent prosternai horn is present, and there is a median sternellum (Fig. 2 3 . I F ) on the prosternum i n all Nearctic genera except Phryganea.

In contrast to most other case-making families, the

mesonotum and metanotum are largely unsclerotized, although small sal and sal mesonotal sclerites occur i n a few genera; both meso- and metanota have small, convex, ovoid sa3

sclerites bearing several setae. The characteristic arrangement o f light markings on both meso- and metanota (e.g. F i g . 23.1B) appears to coincide w i t h the attachments of muscles to the cuticle. The coxal combs are comb-like spines, present on the basal leg segments i n all genera, but, under moderate magnification o f approximately 50x, are seen i n most only as raised points (Fig. 23.9E); the coxal combs are larger and of taxonomic use in t w o genera, Agrypnia

(Fig. 23. I D , E ) and Phryganea

(Fig. 23.8E, F). Mouthparts of the Phryga-

neidae (Fig. 23.5D) have a slender, sclerotized maxillary lobe similar to that o f several groups i n the Spicipalpia and Annulipalpia, and different from the short, rounded lobe o f other families i n the Integripalpia. Humps o f segment I are prominent and gills single. Segment I always bears t w o ventral gills on each side; segments I I - V usually have a complete set o f six single gills on each side, but gills are frequently absent from succeeding segments. Arrangement o f gills often provides characters o f taxonomic value, but is subject to variation w i t h i n species. The lateral abdominal fringe o f bifid filaments is well 374

23 F a m i l y P h r y g a n e i d a e developed, but lamellae are absent; segment I X bears a small dorsal sclerite w i t h at least one pair o f major setae (Fig. 23.1G), sometimes t w o . There are t w o subfamilies: the Yphriinae, w i t h a single genus and species Yphria

fornica

cali-

(Banks), are markedly different i n all stages from the others, and are probably the

more primitive group i n the family (Wiggins 1962; i n press); the remaining genera are assigned to the Phryganeinae. Larvae o f the Phryganeinae usually cut pieces o f leaves and bark to construct cases o f two types; i n spiral construction (Fig. 23.8c, D ) the pieces are fastened i n a continuous spiral ribbon; and i n ring construction (Fig. 23.9c, D ) the pieces are fastened to form discrete sections j o i n e d end to end. As i n spiral cases o f the leptocerid genus Triaenodes,

Phryganea

cases o f

are known to be both dextral or sinistral w i t h i n the same species; this is proba-

bly a variable feature o f behaviour in all phryganeids constructing spiral cases. Phryganeid larvae removed from their cases have greater ability for re-entry than do those o f most other families ( M e r r i l l 1969), thus compensating for the speed w i t h which they voluntarily abandon their cases when disturbed. Larvae i n all other families that construct tubular cases show marked reluctance to abandon them. Phryganeid larvae leave the posterior end o f their cases completely open until just prior to pupating; at that time the larva conceals its case by burrowing into bottom sediments or into rotting logs. The posterior end is sealed with a perforate sieve membrane o f silk, as is the anterior end o f the case i n several genera; this is the normal behaviour for Trichoptera. B u t i n some phryganeid genera, the anterior closure mesh is not spun, and only a loose plug o f debris is fastened w i t h silk over the opening; correlated w i t h this specialized behaviour are the reduced pupal mandibles i n such genera as Banksiola,

Ptilostomis,

Beothukus,

Oligostomis,

and Hagenella

(Wiggins

1960a; i n press), some o f the very few examples o f adecticous or non-functional pupal mandibles i n the Trichoptera (Hinton 1971). Observing living larvae, one sees that the suberuciform phryganeids are more active and agile than larvae o f other tube-case families, and that they are less dependent on their case than the others. On evidence derived from all stages, the Phryganeidae are regarded as among the more primitive o f the tube-case makers (Gall and Wiggins, i n press); and perhaps these unusual features can be interpreted as representing some o f the transitional stages leading to eruciform larvae and their greater dependence on cases. In this connection i t may be relevant that arrangement o f the tracheal system o f phryganeid larvae is unique and distinct from that o f other tube-case-making families (Novak 1952). The taxonomy and phylogeny o f the Phryganeidae have been treated elsewhere (Wiggins, i n press). K e y to G e n e r a * 1

Ventral surface o f head w i t h genae mostly contiguous, separated only near anterior border by small ventral apotome (Fig. 23. 10D); case o f both plant and rock pieces (Fig. 23.10c). Western

(subfamily Yphriinae) 23.10 Y p h r i a

Ventral surface o f head w i t h genae almost completely separated by ventral apotome (Fig. 23.2D)

(subfamily Phryganeinae) 2

*See qualifications under Use of Keys, p. 7. 375

23 Family Phryganeidae 2

(1) Each mesonotal sal seta arising near anterior edge of rounded sclerite of diameter several times larger than sa3 sclerite (Fig. 23.6B); case of ring construction (Fig. 23.9c, D ) 3 Mesonotal sal seta lacking rounded sclerite, or seta arising from centre of small sclerite of diameter smaller than sa3 sclerite (Fig. 23.5B); case usually of ring or spiral construction 4

3

(2) Antennae long, approximately equal in length to diameter of cluster of stem23.3 Beothukus mata (Fig. 23.3B). Northern and central Antennae shorter than above (Fig. 23.6B). Eastern and central 23.6 Oligostomis

4

(2) Head and pronotum uniform light brown, without contrasting light and dark markings except for muscle scars on head (Fig. 23.5B); case of ring construction (Fig. 23.5c). Northeastern, central 23.5 Hagenella Head and pronotum with dark markings contrasting prominently with light or brownish yellow ground colour (Fig. 23.1B)

5

5

(4) Coxal combs of fore legs well developed, their structure (Fig. 23. I D , E) apparent at relatively low magnification of approximately 50x

6

Coxal combs of fore legs small (Fig. 23.9E), appearing as tiny raised points at a magnification of approximately 50x 7 6

(5) Small, pigmented sclerite (sternellum) usually present between prothoracic coxae (Fig. 2 3 . I F ) ; coxal combs on prothoracic legs with axis of base transverse to long axis of coxa (Fig. 2 3 . I D ) , coxal combs of mesothoracic legs with basal axes both transverse and parallel to long axis of coxa (Fig. 23. I E ) ; case usually of spiral construction. Widespread 23.1 Agrypnia Sternellum between prothoracic coxae lacking; coxal combs on both pro- and mesothoracic legs with basal axis transverse to long axis of coxa (Fig. 23.8E, F); case of spiral construction (Fig. 23.8D). Widespread 23.8 Phryganea

7

(5) Meso- and metanota with pair of longitudinal, irregular, dark bands (Fig. 23.2B); case of spiral construction (Fig. 23.8D)

8

Meso- and metanota mostly uniform in colour without dark bands (Fig. 23.4B) 8

9

(7) Segments VI and VII with anterodorsal gills present, segment VII with posteroventral gills absent (Fig. 23.2A). Widespread 23.2 Banksiola Segments VI and VII with anterodorsal gills absent, segment VII with posteroventral gills present (Fig. 23.7A). In North America only in Yukon and Alaska 23.7 Oligotricha

376

23 Family Phryganeidae 9

(7) Pronotum with dark line only along anterior border (Fig. 23.4B); case basically of spiral construction, but trailing ends give it a bushy, irregular appearance (Fig. 23.4c). Central and northern 23.4 Fabria Pronotum with transverse dark band on each side, more central in position and not along anterior border (Fig. 23.9B); case of ring construction (Fig. 23.9c, D ) . Transcontinental 23.9 Ptilostomis

377

23.1

Genus

Agrypnia

D I S T R I B U T I O N AND S P E C I E S

This is essentially a genus o f the northern Holarctic

region w i t h ten species known in North America. Most Nearctic species are transcontinental and northern i n distribution, and some follow montane areas southward to Georgia and California (Wiggins, in press). Two species, A. pagetana

Curtis and colorata Hagen, have

a broad Holarctic distribution; two other Eurasian species occur i n North America only i n the extreme northwest (Wiggins and Parker, i n press). We have associated material for seven species o f Agrypnia\

key were given for A. improba (Hagen), A. pagetana

larval descriptions and a

Curtis, A. straminea

Hagen, and A .

vestita (Walker) by Wiggins (1960b; i n press). The larva of A . vestita was described by

Ross (1944), but the larva described as that species by L l o y d (1921, Phryganea probably Banksiola

crotchi.

vestita) is

The coxal combs of North American Agrypnia

larvae differ consider-

species are larger than those o f other genera except Phryganea,

and are confined to a

MORPHOLOGY

ably in size, those o f A. vestita being the smallest; but as a group the combs o f Agrypnia smaller area (D, E ; cf. Ptilostomis

Fig. 23.9E). In Agrypnia

larvae, the basal axes of the

coxal combs on the prothoracic legs are transverse to the long axis of the coxa, but on the mesothoracic legs the basal axes are both transverse and parallel to the long axis of the coxa. Markings o f the head and pronotum are not consistent among Agrypnia larvae ( W i g gins 1960b, figs. 7-10; i n press); in some species the median dark band o f the frontoclypeus is lacking and i n others the pronotum bears dark markings on the anterior margin but lacks the oblique bands o f the one illustrated. Most, but not all, Agrypnia

larvae have

characteristic meso- and metanotal markings of dark blotches broken up by light areas along the lines o f muscle attachments (B). Length of larva up to 30 m m . CASE

Larval cases of Agrypnia

species are usually constructed of pieces of leaves and

bark arranged spirally (C), the individual pieces closely fitted and without trailing ends. Larvae of Agrypnia pagetana

occasionally use a piece of hollow stem as a case. Length of

larval case up to 50 m m . BIOLOGY

These are species of lakes, marshes, and slow-flowing rivers; larvae were

found as deep as 45 m i n Lake Superior (Selgeby 1974). Guts of larvae (3) we examined all contained arthropod parts.

Agrypnia

improba (Ontario, Peel Co., 29 M a y 1955, ROM)

A, larva, lateral x5; B , head and thorax, dorsal; C , case x3; D, fore coxa, ventral; E , middle coxa, ventral; F, prothorax, ventral; G , sclerite of segment I X , dorsal 378

Phryganeidae: A g r y p n i a

23.1

379

23.2 Genus Banksiola D I S T R I B U T I O N AND S P E C I E S Banksiola is exclusively a Nearctic genus. Five species are known; four are restricted to eastern parts of the continent from Nova Scotia to Minnesota and Florida, but the most common species, B. crotchi Banks (syn. B. se Una Betten), is transcontinental. Larvae of three species have been described (Wiggins 1960b; in press): B. crotchi, B. dossuaria (Say), and B. smithi (Banks). The larva assigned to Phryganeid Genus A by Ross (1944, 1959) is probably B. crotchi, but that assigned to Banksiola selina is probably Agrypnia straminea. M O R P H O L O G Y Larvae of some species of Banksiola have a median dark band on the frontoclypeal apotome (Wiggins 1960b, figs. 11, 12), but in B. crotchi the band is absent (B); the dark pronotal bands are parallel in B. dossuaria. Dark bands on the membranous meso- and metanota (B) are characteristic of all Banksiola now known, and provide a ready character for field identification of even early instars; Oligotrichia, a related genus also characterized by these bands, is confined to Yukon and Alaska in North America. Tibiae of the fore and middle legs are somewhat more expanded distally in Banksiola (A) and Oligotricha than in some other phryganeid genera. Gill characters given in the key for separating these two genera in North America may not hold for subterminal instars or for the two eastern species of Banksiola not yet known as larvae. Length of larva up to 22 mm. CASE Larval cases are constructed of pieces of plant materials arranged spirally (C) and often with some ends trailing. Length of larval case up to 45 mm. B I O L O G Y Banksiola larvae occur in lakes, marshes, and sluggish streams, but not in seasonally transient waters. Larvae of B. crotchi in a British Columbian lake hatched from eggs in August and September, and most passed through the first three or four instars before November, feeding mainly on filamentous algae; fifth instars were almost exclusively predacious (Winterbourn 1971b). Larvae burrowed in bottom sediment where they pupated, and emergence began in July. This species, probably the most common and widespread North American phryganeid, appears to be a very successful ecological generalist. R E M A R K S Taxonomy and distribution of Banksiola adults were reviewed by Wiggins (1956; in press).

Banksiola crotchi (Oregon, Jefferson Co., 1 June 1968, R O M ) A, larva, lateral x7, tibiae and tarsi enlarged; B, head and thorax, dorsal; C, case x3; D , head, ventral 380

Phryganeidae: Banksiola 23.2

381

23.3

Genus

Beothukus

D I S T R I B U T I O N AND S P E C I E S The genus Beothukus was erected for a single species, B. complicatus (Banks), from north central North America (Wiggins and Larson 1989). Records are available from Newfoundland, Q u é b e c , Ontario, Wisconsin, and Alberta. Throughout its range, this species is local and uncommon. M O R P H O L O G Y A m o n g the phryganeid genera o f N o r t h America, larvae o f Beothukus share w i t h Oligostomis two prominent sal sclerites on the mesonotum (B). As in most phryganeid larvae, sclerotized areas of the head and pronotum are yellow w i t h dark markings; the pronotum bears a diagonal dark blotch on each side, and the head lacks a median frontoclypeal band. The coxal combs are small, somewhat larger on the first legs than i n Oligostomis, smaller on the second and third legs. Beothukus larvae are distinguished from all others i n the Phryganeidae by unusually long antennae, subequal to the width o f the pigmented area o f each cluster of stemmata (B). Length of larva up to 20 m m . C A S E The case o f B. complicatus (E) is typically phryganeid i n its construction from small pieces of plant material cut to the appropriate length. The pieces are fastened together into rings, behaviour congruent w i t h morphological evidence for affinity o f Beothukus w i t h Oligostomis (Wiggins, in press). Length of larval case up to 40 m m . B I O L O G Y The life cycle of B. complicatus has been studied at only one site - sphagnum bog pools i n Newfoundland (Wiggins and Larson 1989). The species was univoltine, and larvae passed the winter as fifth instars. Gut contents of larvae were mostly filamentous algae and vascular plant fragments, but animal material such as insects, crustaceans, mites, and rotifers was also consumed. The p H of the pools was 4.2 to 4.9, but i t is not known whether Beothukus is confined to sphagnum bogs. R E M A R K S The systematic relationships o f this unusual species were obscure for a long time, but were resolved through discovery of the larva and pupa (Wiggins 1961 and in press; Wiggins and Larson 1989). The supporting evidence was accumulated gradually, mainly from populations i n Newfoundland, and the generic name Beothukus is based on the name o f the aboriginal inhabitants of the island - now extinct. For many years this species was assigned to the genus Fabria (q.v.).

Beothukus complicatus (Newfoundland, nr. St John's, M a y 1986, ROM) A, larva, lateral x7, detail of anal claw; B, head and thorax, dorsal, detail o f antenna; C, case x2; D, diagram showing ring structure of case; E, head, ventral; F, mandibles, dorsal. (From Canadian Journal o f Zoology) 382

Phryganeidae: Beothukus 23.3

383

23.4

Genus

Fabria

D I S T R I B U T I O N AND S P E C I E S A single North American species is now assigned to the genus Fabria; F. inomata (Banks) is k n o w n from Ontario and Q u é b e c through Illinois, Iowa, Manitoba, and Minnesota to the Northwest Territories (Wiggins, in press). This species is rare and highly localized. The larva o f F. inomata Ontario (Wiggins 1977).

was first identified in the literature from specimens reared i n

M O R P H O L O G Y The larva o f F. inomata (A, B) is essentially similar to all others in the Phryganeinae. Markings of the head and pronotum are closest to Agrypnia vestita ( W i g gins 1960b, f i g . 10), but the meso- and metanota i n F. inomata are uniformly pigmented and lack the dark blotches of that species. Gills are all present on abdominal segments I v i i ; segment v m bears the three anterior gills and a prominent posterolateral lobe on each side (A). Length o f larva up to 32 m m . C A S E The case of F. inomata (C) is highly characteristic, and readily distinguished from any other North American caddisfly. The basic spiral construction o f phryganeine cases can be made out, but is obscured by the long trailing ends of component pieces that give this case a unique bushy aspect. Length of larval case up to 55 m m . B I O L O G Y Our collections indicate that larvae of F. inomata live i n dense beds of submerged aquatic plants i n standing or slowly m o v i n g waters; shallow areas where Ceratophyllum and Potamogeton flourish are typical of these sites. Larvae tend to use fresh green pieces o f these same plants i n construction, and the resultant cases are difficult to distinguish from the plants; the trailing ends o f l i v i n g plant pieces probably also give additional buoyancy to the case, helping the larva to maintain its position near the surface. Gut contents o f larvae (3) examined were vascular plant pieces and fine organic particles. R E M A R K S A second species, F complicata (Banks), assigned to this genus for many years (Wiggins 1977), has been transferred to a new genus, Beothukus (q.v.).

Fabria inomata (Ontario, Leeds Co., 27 A u g . 1966, ROM) A, larva, lateral x7; B, head and thorax, dorsal; C, case x3 384

Phryganeidae: F a b r i a

23.4

385

23.5

Genus

Hagenella

D I S T R I B U T I O N A N D S P E C I E S Hagenella is a Holarctic genus w i t h one species in Europe, two in Asia, and one in North America; H. canadensis (Banks) is known from New Brunswick and New Hampshire through Q u é b e c , Ontario, and M i c h i g a n to Wisconsin and Minnesota. The North American species is rare and highly localized. No larva has been associated positively with adults of H. canadensis. The larva illustrated here, and provisionally assigned to this species, is one of the few that we have collected in Ontario. These larvae are considerably different from any other North American phryganeids now k n o w n , but are similar to the European and Asian species o f Hagenella (Wiggins, in press). They are almost certainly Hagenella canadensis. M O R P H O L O G Y The larvae are unique among phryganeids now k n o w n in having the head and pronotum uniformly brown and without contrasting markings (A, B ) ; rounded muscle scars are evident on the head. Meso- and metanotal setae i n positions sal and sal have a small sclerotized area around the base; although there is some tendency for this i n other genera, the sclerotized setal bases i n this larva are considerably larger and darker than i n the others, apart from Oligostomis and Beothukus. The ventral apotome of the head (D) is narrower than i n other phryganeid genera; segment V I I I is without gills. I n other characters the larva is typical o f the Phryganeinae. Length o f larva illustrated 21 m m . C A S E The larval case (C) is constructed o f leaf pieces arranged to form ring-like sections joined end to end. Length o f case illustrated approximately 20 m m . B I O L O G Y Our larvae were taken i n a small pool, apparently sustained by floodwater from a nearby stream. Larvae o f another Hagenella species were taken i n similar habitats in Japan, and the European species occurs i n sphagnum bog pools (Wallace and Wiggins 1978).

Hagenella canadensis (Ontario, Nipissing Dist., Samuel de Champlain Prov. Park, 15 May 1972, ROM 720139) A, larva, lateral x7; B , head and thorax, dorsal; C, case, lateral x5; D , head, ventral 386

P h r y g a n e i d a e : H a g e n e l l a 23.5

387

23.6

Genus O l i g o s t o m i s

D I S T R I B U T I O N AND S P E C I E S Oligostomis is a Holarctic genus, with two North American species: O. ocelligera (Walker) distributed from Wisconsin to Newfoundland, south to New Jersey and Tennessee; and O. pardalis (Walker) from Ontario to Newfoundland, south to Massachusetts and N e w York. Larvae o f both species were described by L l o y d (1921); we have associated material for both (Wiggins 1960b). M O R P H O L O G Y Larvae o f Oligostomis are distinctive from most other North American phryganeids in having a rounded sclerite at the base o f each mesonotal sa 1 seta (B); the diameter of the sclerite is approximately three times that o f the sa3 sclerite. The pronotum has an oblique angular dark mark on each side, but the anterior margin is without dark markings. The largest seta at mesonotal sal and metanotal sal and sal frequently has a very small sclerotized area around the base. Abdominal gills are complete only on the first four segments, anterodorsal gills are absent from segments V to V I I inclusive, and segment V I I I lacks gills entirely. Length of larva up to 24 m m . Larvae o f the two species appear to differ only in size; but rather than the total length used previously to distinguish them (Ross 1944; Wiggins 1960b), a more effective index w o u l d probably be the w i d t h o f the anterior border of the frontoclypeal apotome. We do not have sufficient material of proven identity to establish a range, but this measurement from exuviae o f a reared female of each species is: O. pardalis 1.60 m m ; O. ocelligera 1.13 m m . C A S E Larval cases i n Oligostomis (c) are composed of ring-like sections o f leaf and bark pieces joined together as i n Ptilostomis (Fig. 23.9c). Length o f larval case up to 50 mm. B I O L O G Y Oligostomis larvae live in cool forest streams, generally i n sections o f slow current where leaves accumulate. Larvae o f O. pardalis (3) that we examined had ingested animal remains as w e l l as filamentous algae and some vascular plant tissue. Food o f the European O. reticulata ( L . ) was found to be largely insects (Smirnov 1962). R E M A R K S Although O. pardalis has been frequently assigned to Eubasilissa past, that genus is confined to Asia (Wiggins 1960a; i n press).

Oligostomis pardalis (Ontario, York Co., 20 Oct. 1951, ROM) A, larva, lateral x6; B, head and thorax, dorsal; C, case x3 388

in the

Phryganeidae: Oligostomis 23.6

389

23.7

Genus

Oligotricha

D I S T R I B U T I O N AND S P E C I E S Oligotricha is entirely Palaearctic except for an extension o f the Eurasian species O. lapponica (Hagen) into Alaska and Yukon (Wiggins and Parker, in press). Five species are known, three of them in Japan (Wiggins and Kuwayama 1971). The larva o f O. lapponica was described by Silfvenius (1905) and Lepneva (1966), among others. M O R P H O L O G Y The larva o f O. lapponica is similar to species of Banksiola, but in so far as the latter are k n o w n , O. lapponica can be distinguished by the presence of posteroventral gills on segment VII and absence o f anterodorsal gills on segments VI and VII (A). Larvae of both Oligotricha and Banksiola are distinctive i n the parallel dark bands on the meso- and metanota (B). Since Banksiola crotchi (Fig. 23.2B) is the only species of that genus i n western N o r t h America, and lacks a median dark band on the frontoclypeus, O. lapponica w o u l d be distinctive among these related western larvae because the median dark band is present. Length of larva illustrated 18 m m . C A S E Larval cases o f Oligotricha species are made of short lengths of plant pieces arranged spirally (C); i n contrast to cases o f Banksiola, trailing ends of plant pieces are lacking. Length of larval case illustrated 28 m m . B I O L O G Y The habitat o f O. lapponica and O. striata ( L . ) in Europe and Asia is slowly flowing or standing waters, often the brown-water drainage ditches of peatlands (Lepneva 1966). Food of the European O. striata was reported as largely insect larvae (Siltala 1907b). R E M A R K S N o North American larvae o f this species have yet been positively identified. The specimen illustrated here was provided by J.O. Soiem.

Oligotricha lapponica (Norway, 24 A u g . 1968, DKNVS Museet 3106) A, larva, lateral x8; B, head and thorax, dorsal: C, case x3 390

Phryganeidae: Oligotricha

23.7

391

23.8

Genus

Phryganea

D I S T R I B U T I O N AND S P E C I E S

The genus Phryganea

is widely distributed through

the Holarctic region. T w o species occur in North America: P. cinerea Walker extends from

Newfoundland to Alaska, south to California, Pennsylvania, and Massachusetts; P. sayi M i l n e (syn. P. interrupta

Say) is an eastern and central species occurring from Maine

through southern Ontario to Wisconsin, south through Missouri to North Carolina. These two species overlap i n a broad belt from N e w Hampshire through the southern Great Lakes area. We have associated larvae of both species (Wiggins 1960b), but I am unable to distinguish between them structurally. The larva o f P. cinerea was described by Neave (1933), and the larva o f P. sayi by Vorhies (1909); L l o y d ' s (1921) description of P. cinerea is not o f that species, but probably pertains to Banksiola MORPHOLOGY

(Wiggins 1960b).

Phryganeid coxal combs reach m a x i m u m development in

Phryganea

(E, F ) , their basal axes consistently transverse to the long axis o f the coxa. This is the only phryganeid genus i n N o r t h America i n which the prosternai sternellum (Fig. 2 3 . I F ) is lacking. D a r k markings on the head and pronotum o f P. cinerea are variable (Neave 1933); the median dark band on the frontoclypeus may be shorter than the sclerite, and the dark pronotal markings more restricted than illustrated here. Membranous areas are usually green i n l i v i n g larvae. Length o f larva up to 43 m m . CASE

Larval cases i n this genus are normally constructed o f short lengths o f plant mate-

rials arranged to form a continuous spiral (C, D). Larvae taken far from shore in the deepest parts o f Lake Winnipeg, where plant detritus is rare, used animal parts for building cases (Neave 1933): ostracods, cladoceran ephippia, fish scales, sclerotized parts of insects, snails and their opercula. M a n y o f the ostracods were affixed while alive. Case-building behaviour i n P. cinerea was studied by W i l l i a m s and Penak (1980). Length o f larval case up to 56 m m . BIOLOGY cinerea

Phryganea

larvae are most often found in marshes and lake margins, but P.

has been recorded at depths o f 20 m i n Lake Winnipeg (Neave 1933), and to 100

m in Lake Superior (Selgeby 1974). Larvae ingest dead and l i v i n g plant, as w e l l as animal, materials; the offshore larvae studied by Neave (1933) consumed oligochaetes, copepods, ostracods, cladocerans, and algae.

Phryganea

cinerea (Ontario, Peel Co., 18 Nov. 1955, ROM)

A, larva, lateral x4; B , head and thorax, dorsal; C, case x2; D , diagram showing spiral structure o f case; E, fore coxa, ventral; F, middle coxa, ventral, coxal comb enlarged 392

Phryganeidae: Phryganea 23.8

393

23.9

Genus P t i l o s t o m i s

D I S T R I B U T I O N AND S P E C I E S Ptilostomis is a Nearctic genus of four species: P. ocellifera (Walker) and P. semifasciata (Say) are transcontinental; P. postica (Walker) and P. angustipennis (Hagen) are known only from the eastern half of the continent. The larva o f P. ocellifera

was described by Vorhies (1909, as Neuronia postica)

Ross (1944). We have associated larvae for P. ocellifera

and semifasciata

and by

(Wiggins 1960b)

and also for P. postica, but diagnostic characters have not been found for separation o f any of these species.

M O R P H O L O G Y Ptilostomis larvae (B) have a transverse dark marking on each side o f the pronotum, separated from the anterior border by an area o f yellow ground colour o f approximately the same length. The head lacks a median dark band. Tibiae of the fore and middle legs are broad distally, much as i n Banksiola; at magnifications of approximately 50x the coxal combs in Ptilostomis are seen only as tiny points spread over much of the ventral surface o f the coxa (E). Abdominal gills of the first six segments are complete, on segment VII the anterolateral g i l l is variable, and on VIII all three anterior gills are present, although the anterodorsal g i l l is variable i n occurrence (A). Other structures are typical for the Phryganeinae. Length of larva up to 35 m m . CASE

Larval cases in Ptilostomis

are of ring-like sections of leaf pieces j o i n e d end to

end (C, D). Length of larval case up to 60 m m . B I O L O G Y Larvae of Ptilostomis are noteworthy for their occurrence i n an unusually wide range o f aquatic habitats. We have taken larvae in both lentic and lotie waters, ranging from cool streams to lakes and temporary vernal pools. Ptilostomis ocellifera was reared from a temporary vernal pool (Wiggins et al. 1980); and final instars o f this species were present in the littoral region o f a British Columbia lake from November to June (Winterbourn 1971a), where late instars were largely predacious in feeding. To what extent other species are as generalized i n habitat has yet to be determined.

Ptilostomis ocellifera (Ontario, York Co., 16 M a y 1958, ROM) A, larva, lateral x6; B, head and thorax, dorsal; c, case x2; D, diagram showing ring structure o f case; E, fore coxa, ventral, showing minute coxal combs 394

Phryganeidae: Ptilostomis 23.9

395

23.10 Genus Yphria D I S T R I B U T I O N AND S P E C I E S In the remarkable Nearctic genus Yphria there is a single species, Y californica (Banks), recorded from California and Oregon. All stages have been described and the systematic relationships of the species assessed (Wiggins 1962; in press); Y californica is the sole member of the subfamily Yphriinae, and the most primitive living phryganeid. The geographic distribution and habitat of this species appear to place it outside the range of other potentially competing species of the family. M O R P H O L O G Y The larva is unique among all of the Phryganeidae in having the ventral apotome reduced to a small anterior sclerite ( D ) . Yphria larvae are further distinguished by enlarged mesonotal sal sclerites contiguous mesally ( B ) ; mesonotal sal sclerites are present but small and separate. Meso- and metanotal sa3 sclerites are convex and ovoid. Length of larva up to 22 mm. CASE The larval case is unlike that of any other North American phryganeid, nor is it likely to be confused with cases in any other genus. Pieces of rock, bark, and twigs are used, but the rock fragments are placed anteriorly for the most part, and extended posteroventrally (C) as a wedge that concentrates the weight of the case ventrally in accordance with its orientation by the larva. The diameter of the posterior opening of the larval case is not reduced with silk as in all Phryganeidae. At pupation, Yphria larvae construct an entirely new and less rigid case of mica-like mineral fragments (Wiggins 1962, fig. 7); other larvae (Phryganeinae) pupate in the larval case, but in the Asian family Phryganopsychidae, larvae also construct an entirely new case for pupation (Wiggins and Gall 1993, figs. 8, 9). Length of larval case up to 33 mm. B I O L O G Y We have collected larvae of K californica from many localities, but always on bottom materials in pools and along the margin of small, cool mountain streams. Larvae move with exceptional agility, and when disturbed or picked up, their immediate reaction is to vacate the case. The rate of development is variable, but collection of early- to late-instar larvae, adults, and eggs in June suggests a life cycle of more than one year. Larvae burrow in coarse sediments for pupation. Gut contents of larvae (3) indicate that at least the late instars are mainly predacious.

Yphria californica (Oregon, Deschutes Co., 23 April 1964, R O M ) A , larva, lateral x8; B , head and thorax, dorsal; C , case, lateral x4; D , head, ventral, ventral apotome enlarged; E, mandibles, dorsal 396

Phryganeidae: Yphria 23.10

397

This page intentionally left blank

24 Family Rossianidae

This family o f t w o western N o r t h American genera was recognized i n an extensive phylogenetic analysis o f the Limnephiloidea (Gall and Wiggins, in press). It is supported by derived character states o f larvae, pupae, and adults; these states are not congruent w i t h any of the related families. Larvae o f the Rossianidae are distinctive from all other case-making families. The head and pronotum bear coarse surface sculpturing; the mesepisternum is modified by prominent surface sculpturing. Primary sclerotized plates o f the me so no tu m are subdivided into two or three pairs of secondary sclerites. Setae o f the metanotum are confined mainly to three pairs o f separate well-developed sclerites. The abdomen bears single gills; bifid filaments o f the lateral fringe are w e l l developed, and forked lamellae occur on several segments. Chloride epithelia are lacking. The mandibles are toothed, and bear a mesal tuft o f stout setae. The antennae are located more or less midway between the eye and the anterior margin o f the head capsule. Larvae construct tubular cases o f rock fragments. The single species i n each genus is very highly localized and seldom found. The larval habitat is small, cold mountain streams. K e y to G e n e r a * 1

Dorsum o f head concave, w i t h prominent lateral flange on each side, pronotum concave laterally, mesepisternum granulate (Fig. 24.2A, B, E ) . Western montane 24.2 Rossiana Head and pronotum lacking flange or carina (Fig. 24.1A, B ) , mesepisternum extended slightly as spiny lobe (Fig. 24.lG). Western montane

24.1 Goereilla

See qualifications under Use of Keys, p. 7.

:

399

24.1 Genus Goereilla D I S T R I B U T I O N AND S P E C I E S Goereilla is an unusual case-making genus found only in western North America; a single species G. baumanni Denning is known from Montana and Idaho. We reared larvae from Montana. M O R P H O L O G Y The head is sculptured; the mandibles have separate tooth-like points ( E ) and the labrum is not membranous anteriorly ( D ) . The pronotum has pebbled surface sculpturing, and bears a few coarse teeth on the anterior margin (A), but is not thickened laterally. Mesonotal sclerites are subdivided into three pairs; the mesepisternum is modified to form a rounded, spinose lobe (A, G ) . All three metanotal sclerites are large (B). The basal seta of all tarsal claws is short (A). Abdominal gills are single and chloride epithelia are lacking; a lateral fringe and forked lamellae are present. Setae of the basal tuft of the anal proleg arise from the dorsal plate ( F ) ; a large accessory hook is present on the anal claw (A). Length of larva up to 9 mm. CASE Larvae of G. baumanni construct smoothly contoured cases of sand grains with a few small pieces of detritus. The posterior opening is reduced with silk to a central hole with a crenulate margin (C). Length of larval case up to 11 mm. B I O L O G Y Larvae live in the watery organic muck of spring seepage areas; they are almost impossible to see in these habitats, but can be collected by washing samples of the material in a fine-mesh sieve in flowing water. Gut contents of larvae (3) examined were pieces of vascular plants with fine organic particles. We have collected larvae sealed up in pupal cases in August; adults were recorded in May. R E M A R K S A more extensive account of the larva, pupa, adults, and life history of this species appeared elsewhere (Wiggins 1976).

Goereilla baumanni (Montana, Missoula Co., 17-18 August 1973, R O M ) A, larva, lateral x21, anal claw enlarged; B, head and thorax, dorsal; C, case, lateral x l l ; D , labrum, dorsal; E , mandible, ventral; F, segment I X and anal prolegs, dorsal; G , mesopleuron, lateral 400

Rossianidae: Goereilla 24.1

401

24.2 Genus Rossiana D I S T R I B U T I O N AND S P E C I E S Rossiana is a distinctive Nearctic genus; a single species, R. montana Denning, is known from Montana, Washington, and British Columbia. The larva of R. montana was identified from an associated series of larvae and mature pupae collected in Montana (Wiggins 1977). M O R P H O L O G Y Structurally, larvae of R. montana are among the most unusual of the case-makers. The posterolateral margins of the head are extended as prominent flanges, and the pronotum is concave on each side ( B , E ) ; the head and pronotal sclerites are brownish red and coarsely pebbled. The mandibles have separate tooth-like points ( H ) , and the labrum is sclerotized but unpigmented anteriorly ( G ) ; the ventral apotome is uniquely pegshaped ( D ) . Each mesonotal plate is subdivided by a longitudinal gap in the sclerotization, and the membranous separation on the mid-dorsal line between the sclerites is unusually wide ( B ) ; metanotal sclerites are indistinct. The basal seta of the middle and hind tarsal claws (A) is longer than in Goereilla, but does not reach the end of the claw. Abdominal gills are single and long, chloride epithelia are absent; forked lamellae occur on several segments and the lateral fringe is well developed. The anal claw bears an accessory hook ( F ) . Length of larva up to 9 mm. CASE The larval case (C) is constructed of small rock fragments, somewhat curved, but with little taper. Length of larval case up to 10.5 mm. B I O L O G Y This species is characteristic of small, cold, mountain streams and is very local in occurrence. We have taken larvae in gravel under moss in shallow water at the edge of streams, and on vertical rock surfaces in a thin layer of running water. Guts of larvae (3) we examined contained mostly plant fibres, suggesting that woody materials are ingested, and fungi. Pupae and larvae of the last three instars were taken in a single collection in June. R E M A R K S Morphology of adults was reviewed by Schmid (1968b).

Rossiana montana (Montana, Missoula Co., 24 June 1968, R O M ) A, larva, lateral xl2, tarsal claw enlarged; B , head and thorax, anterolateral; C, case x9; D , head, ventral; E , head, frontal; F, segment I X and anal prolegs, dorsal; G , labrum, dorsal; H , mandible, dorsal 402

Rossianidae: Rossiana 24.2

403

25 Family Sericostomatidae

The Sericostomatidae sens. str. are represented in all faunal regions except the Australian, usually by a small number o f genera and species. The twelve North American species have been assigned to three genera (Ross and Wallace 1974). Representatives are widespread through the eastern half of the continent and i n the west. Larvae are generally found in running waters, often i n small springs, but also in the l i t toral zone o f lakes. Observations indicate that larvae of at least the two eastern genera, Agarodes Gumaga

and Fattigia,

are burrowers in sandy deposits; evidently those of the western

do not burrow to the same extent. Sericostomatid larvae feed mainly on plant

materials, and appear to be principally detritivorous. Six larval instars were attributed to the European species Sericostoma

personation

in most families; larvae o f Gumaga nigricula

(Spence) (Elliott 1969), compared to five ( M c L . ) moult up to 14 times (Resh et al.

1981). Nearctic sericostomatid larvae have a number of distinctive features. The head lacks much o f the normal ventral pigmentation, and bears a dorsolateral ridge on each side. The labrum is rather narrow, and the mandibles have several tooth-like points; the ventral apotome is roughly triangular, separating the genae incompletely. The pronotum lacks the prominent posterior transverse ridge o f the Limnephilidae and allied families, prosternai sclerites are absent and there is no prosternai horn; the fore trochantin is relatively large and hook-shaped, the fore femur broad and flat. The mesonotum tends to be sclerotized posteriorly from the primary sclerites, and i n Gumaga the sa3 sclerite is separated from the plate representing the fused sal and sal.

Sclerites of the metanotal setal areas are

indistinct. On abdominal segment I the lateral humps are oblique and flat, are provided w i t h a dense patch o f short setae, and ringed basally by a more or less complete, weak sclerite (Fig. 25.2A); setae on abdominal segment I are sparse, w i t h only the lateral hump seta and usually one on each side o f the dorsal hump and a pair on the venter. Gills, usually single, are present on segment I , and on other segments most gills o f the lateral series are short and single, those of the dorsal and ventral series being either branched or single. Segment v m bears a row o f forked lamellae on each side, and small serrate lamellae occur on other segments; the lateral fringe of the abdomen is absent. Segment I X lacks a 404

25 Family Sericostomatidae well-defined dorsal sclerite but does bear setae on the posterodorsal border (Fig. 25.2E). On the dorsum of each anal proleg there is a characteristic cluster of approximately 30 or more setae mesad from the somewhat reduced lateral sclerite (Fig. 2 5 . I D ) ; the anal claw bears a stout accessory hook, which in some genera has a small accessory hook itself (Fig. 25.1A).

Larval cases are usually made of rock pieces, and are variously tapered and curved. The posterior opening is considerably reduced with silk. In some earlier works on the North American fauna (e.g. Betten 1934) and in many European works (e.g. Hickin 1967), the Lepidostomatinae, Brachycentrinae, and Goerinae were treated as subfamilies of this family, along with the Sericostomatinae. Association of these groups with the Sericostomatidae was a tradition inherited from the time when classification of the Trichoptera was based mainly on data from adult stages, a practice long since rectified (e.g. Ross 1978). Taxonomy of Nearctic sericostomatid adults was reviewed by Ross (1948b) and Ross and Wallace (1974). Key to Genera* 1

Anterolateral corner of pronotum extended into sharp point (Fig. 25.1A); metanotal sal comprising many setae in transverse band on pair of sclerites (Figs. 25.1B, 25.2B) 2 Anterolateral corner of pronotum not extended into sharp point as above (Fig. 25.3A); each metanotal sal consisting of only single seta (Fig. 25.3B). Western 25.3 Gumaga

2

(1) Dorsum of abdominal segment I X with approximately 40 setae (Fig. 25.2E); head flat dorsally, prominent carina at each side (Fig. 25.2A, B ) . Southeastern 25.2 Fattigia Dorsum of abdominal segment I X with approximately 15 setae (Fig. 25. I D ) ; head rounded dorsally, lateral carina less prominent than above (Fig. 25.1A, B ) . Widespread through eastern half of continent 25.1 Agarodes

*See qualifications under Use of Keys, p. 7. 405

25.1

Genus

Agarodes

D I S T R I B U T I O N AND S P E C I E S

The genus Agarodes is confined to the eastern half of

North America from Louisiana and Florida to Minnesota, Ontario, and Maine; ten species are recognized. Some characters for the larva of A. griseus Banks were given by Ross and Wallace (1974). The larva of A. distinctus U l m e r illustrated here is one from series we reared in Ontario; we have larvae of three other species. M O R P H O L O G Y The anterolateral corner of the pronotum is extended anteriorly as a sharp point (A), and each of the three lightly sclerotized setal areas o f the metanotum bears many setae (B); the sa\ setae are arranged in more of a transverse line than those in Fattigia. Most abdominal gills o f the dorsal and ventral series are branched, but those of the lateral series are mainly single and short (A). The dorsum o f segment IX bears four major setae and approximately ten shorter ones along its posterior edge (D). Length o f larva up to 15 m m . CASE

Larval cases i n the genus are made of moderately coarse but uniform rock frag-

ments, and generally are not as elongate as i n Gumaga. Length o f larval case up to 24 m m . B I O L O G Y I n Ontario, we have collected larvae o f A. distinctus i n sand and gravel deposits along the edges of lakes and rivers; but we have taken larvae o f other species o f the genus i n the southeast i n the sand of cool springs. Since Agarodes larvae are rarely seen other than by sifting sand and gravel, I infer that they are chiefly burrowing detritivores i n these materials; guts of larvae (3) we examined contained pieces o f vascular plants and fine organic particles for the most part. REMARKS

Agarodes

Taxonomy o f adults of Agarodes was reviewed by Ross and Scott (1974).

distinctus (Ontario, Algonquin Prov. Park, 31 M a y 1960, ROM)

A, larva, lateral x9, anal claw enlarged; B, head and thorax, dorsal; C, case x8; D, segment IX and anal prolegs, dorsal 406

Sericostomatidae: Agarodes 25.1

407

25.2 Genus Fattigia D I S T R I B U T I O N AND S P E C I E S This genus comprises only F. pele (Ross) of the southeastern United States. Diagnostic characters of the larva were given by Ross and Wallace (1974); we have associated larvae from several localities. M O R P H O L O G Y The dorsum of the head of F. pele is distinctly flattened and the carina prominent laterally (A). As in Agarodes, the anterolateral corner of the pronotum is extended as a sharp point (A), but is directed more ventrally than in that genus; the metanotal sal setae are more scattered than in Agarodes. Most abdominal gills of the dorsal and ventral series are branched, but gills of the lateral series are mostly single. This genus is distinct from the other two in having many setae (approx. 40) on the dorsum of segment I X ( E ) , and several setae (approx. 15) on the mesal surface of the base of the anal claw. Length of larva up to 15 mm. CASE The larval case of F. pele (C) is similar to that of Agarodes species in material and general proportions. Length of larval case up to 18 mm. B I O L O G Y Our collections of F. pele larvae were made in sand deposits of cool springs and streams, mostly by sifting sand. Gut contents of larvae (3) we examined were largely vascular plant tissue and fine organic particles.

Fattigia pele (North Carolina, Macon Co., 20 May 1970, R O M 700363) A, larva, lateral x l l , lateral hump enlarged; B, head and thorax, dorsal; C, case x8; D, fore trochantin, lateral; E , posterior edge of segment I X , dorsal 408

Sericostomatidae: Fattigia 25.2

409

25.3

Genus G u m a g a

D I S T R I B U T I O N AND S P E C I E S Gumaga is a genus of both Japan and western North America. On this continent the group occurs from N e w M e x i c o and Utah through Arizona and California to southern Oregon. Two species are recognized, G. nigricula ( M c L . ) and G. griseola ( M c L . ) . Diagnostic characters o f Gumaga larvae were provided by Ross and Wallace (1974) and by Ross (1959, as Sericostoma). We have associated larvae for both species, and have collected larvae i n many localities. M O R P H O L O G Y The North American larvae of Gumaga are distinguished from the larvae o f other sericostomatids on this continent by several features; the most readily apparent are the lack o f a sharp anterolateral point on the pronotum, the separation o f mesonotal sa3 as a discrete sclerite (A, B ) , and the reduction o f metanotal sal to a single seta ( B ) . A b d o m i n a l gills are always single i n Gumaga (A). The dorsum of segment I X bears approximately six major setae and about the same number of smaller ones (E), similar to Agarodes. Markings of the head and pronotum range from uniform dark brown to prominent white bands on a dark base colour (Resh et al. 1981, fig. 3). Analysis of polymorphism i n larval morphology and i n reproductive biology led Wood and Resh (1991) to infer that separate sibling species exist i n G. nigricula. Length of larva up to 19 m m . C A S E Larval cases i n Gumaga (C) are frequently long and slender, and made of rock fragments, rather smaller pieces than i n cases of the other two genera. Length of larval case up to 29 m m . B I O L O G Y Our collections of Gumaga larvae were made in running water, i n both cold springs and warmer streams. Larvae i n cases were usually inactive, lying exposed on the gravel substrate or beneath rocks, and evidently less inclined to burrow than those o f the other two genera. I n guts o f Gumaga larvae (3) that we examined there was a much higher proportion of fine particles than i n the other sericostomatid genera. A study o f G. nigricula i n California by Resh et al. (1981) revealed that larvae moult as many as 14 times during the life cycle, and that larval instars cannot be determined by measurement of the head capsule as i n most other larval Trichoptera. REMARKS

Taxonomy o f the males of Nearctic Gumaga was reviewed by K i m m i n s and

Denning (1951).

Gumaga nigricula

(Arizona, Coconino Co., 4 M a y 1961, ROM)

A, larva, lateral x l 2 ; B , head and thorax, dorsal; C, case x5; D , head, ventral; E, posterior edge o f segment I X , dorsal 410

Sericostomatidae: Gumaga 25.3

411

This page intentionally left blank

26 Family Uenoidae

This is a distinctive family of North America, eastern Asia including Japan and the northeastern Himalayas, and southern Europe; about 70 species are now known in the world. At the family level larvae are distinguished by the anteromedian emargination of the mesonotum. They are also characterized by a wedge- or T-shaped ventral apotome of the head, a prosternai horn, and a membranous border on the labrum; antennae arise midway between the eye and the anterior margin of the head capsule. The basal seta of each tarsal claw extends nearly to the tip of the claw. Single abdominal gills are present in some genera, but gills are absent in others. Larvae in all genera pupate in aggregations on rocks. Larvae have scraping mandibles with an untoothed blade, and feed by grazing diatoms and fine organic particles from rock surfaces. In all genera except Neophylax larvae are confined to cool rapid headwater streams; this is inferred to be the ancestral habitat for the family since the plesiomorphic genera of both subfamilies occur there (Vineyard et al., in press). However, the biology of Neophylax is different because a number of species in this genus occur at downstream sites in slower currents and warmer water. Longitudinal zonation in stream systems is characteristic of Neophylax, and species occur in consistent sequences downstream from headwater sites (Beam and Wiggins 1987). Prepupal diapause appears to occur throughout Neophylax, and may be a factor in sustaining larvae through periods of up to six months during the reduced flow and higher water temperature of summer. Because of this more efficient use of stream resources through longitudinal zonation, sympatry among Neophylax species is common; about half of the species in the Uenoidae belong to this genus. There are two subfamilies, Uenoinae and Thremmatinae (Vineyard and Wiggins 1988; Vineyard et al., in press). U E N O I N A E : Farula, Neothremma, Sericostriata, and the Asian genus Uenoa. Larvae in these genera are unusually slender, and construct characteristic cases of fine sand or of silk alone (Wiggins et al. 1985). The pronotum is broader anteriorly than posteriorly; larvae have secondary setae on the head, and are also distinguished by spiral thickening in the wall of each lateral abdominal filament, and the forked lamellae are arranged with bifur413

26 Family Uenoidae cate apices directed posteriorly. In Farula and Neothremma, and in the Asian genus Uenoa, pupal cases are sealed posteriorly with a silken sieve membrane fastened subapically within the case. T H R E M M A T I N A E : Neophylax, Oligophlebodes, and the European genus Thremma (Vineyard and Wiggins 1988; Vineyard et al., in press). Larvae are not slender, and the posterior half of the pronotum is broader than the anterior half in dorsal aspect; larvae construct stouter cases of coarser rock particles. The family has been extensively revised and the phylogenetic relationships of the genera assessed (Wiggins et al. 1985; Vineyard and Wiggins 1987, 1988; Vineyard et a l , in press; Wiggins and Erman 1987; Wiggins and Wisseman 1992). The Uenoidae offer an instructive example of the value of larval stages and their behaviour in understanding the relationships of Trichoptera (cf. Schmid 1979 and Wiggins 1981). The genera Neophylax and Oligophlebodes formerly constituted the subfamily Neophylacinae of the Limnephilidae (Schmid 1955); and Thremma was the sole genus of the anomalous European family Thremmatidae. The type genus Uenoa has traditionally been a small group of Asian species of uncertain relationship. Key to Genera* 1

Larvae extremely slender, pronotum broadest anteriorly in dorsal aspect (Fig. 26.1A, B); larvae lacking abdominal gills in North American genera; larval cases very slender, smoothly textured, constructed of small sand grains covered externally with silk (26.1c), or constructed of silk alone (Fig. 26.5c). Western montane North America (subfamily Uenoinae) 2 Larvae not slender, pronotum broadest at about midpoint in dorsal aspect (Figs. 26.2, 26.4); abdominal gills usually present; larval cases not slender, coarsely textured, and constructed of rock fragments of various sizes (Fig. 26.4c), or with larger stones along each side (Fig. 26.2c). Eastern and western North America (subfamily Thremmatinae) 4

2

( 1 ) Mesonotal sclerites with anterior margin straight except for separate notch in anteromesal corner of each sclerite, pronotum with anterior margin straight and anterolateral corner angulate (Fig. 26.5B). Western 26.5 Sericostriata Mesonotal sclerites with anterior margin rounded, and single median notch between two sclerites, pronotum with anterior margin and anterolateral corner curved (Fig. 26.3B). 3

3

(2) Darkened posterolateral corner of each mesonotal sclerite extended approximately to mid-lateral point of sclerite (Fig. 26.3B); abdomen with filaments of lateral fringe arising over half or more of most segments (Fig. 26.3A). Western 26.3 Neothremma

*See qualifications under Use of Keys, p. 7. 414

26 F a m i l y U e n o i d a e Darkened posterolateral corner o f each mesonotal sclerite not reaching mid-lateral point (Fig. 26.1B); abdomen w i t h filaments o f lateral fringe scattered and arising over less than half o f most segments, but w i t h prominent and discrete tuft o f filaments at anterior edge o f segment II (Fig. 26.1A). Western 26.1 F a r u l a 4

(1) Pronotum with prominent longitudinal ridges (Fig. 26.4B); anteromedian notch o f mesonotum weakly represented; case o f rock fragments, strongly tapered and curved, outline smooth (Fig. 26.4c). Western

26.4 Oligophlebodes

Pronotum lacking longitudinal ridges, but mesonotum w i t h prominent anteromedian notch (Fig. 26.2B); case o f coarse rock fragments, larger stones along each side (Fig. 26.2c). Eastern and western

26.2 Neophylax

415

26.1 Genus Farula D I S T R I B U T I O N AND S P E C I E S This genus is confined to western North America, where it is represented by ten species recorded from California, Oregon, and Washington. The larva of F. malkini Ross was characterized by Denning (1973); we have associated series for three species and have collections of larvae from much of the range of the genus. M O R P H O L O G Y Larvae of Farula are very similar to Neothremma and probably have often been so identified. Structurally, these two genera and Sericostriata are quite unlike any others in North America. Larvae are very long and slender, and sclerotized parts are mostly uniform dark brown or black ( A ) . The dorsum of the head bears secondary setae, and the labrum has a membranous anterior fringe ( B ) . In Farula the anterior margin of the pronotum is convex in outline, but lacks serrations and stout setae ( B ) . Each sclerite of the mesonotum is uniformly rounded anteriorly from the lateral margin to the median notch ( B ) , or in some species bears an anterolateral angle as in Neothremma; but the darkened posterolateral corner of each mesonotal sclerite does not extend to the mid-lateral point of the sclerite ( B ) . Larvae of Farula lack a prothoracic sternellum. Abdominal segment II bears an anterolateral brush of bifid filaments ( A ) ; a smaller cluster of lateral filaments at the posterior margins of segments I I - V I I is variable but arises over less than half of each segment. A field of minute spines occurs on the intersegmental area between I V and v as in Neothremma ( A ) ; but chloride epithelium is confined to the sternum of V. Length of larva up to 8.5 mm. CASE Larval cases in both Farula and Neothremma are so very slender that they could be mistaken for conifer needles, but Farula cases are the more slender. The case ( C ) is constructed of fine sand grains fitted closely together, the exterior surface as well as the interior covered with a layer of silk; frequently much of the case is of silk alone. Although the posterior opening of the larval case is not reduced with silk, a subterminal perforate silken membrane is spun across the inside by final-instar larvae in both Farula and Neothremma in constructing a pupation chamber ( C ) . Length of case up to 14.5 mm. B I O L O G Y Species of Farula inhabit small, cold streams in mountainous areas. Larvae graze on rock surfaces, and pupate in clusters on the underside of rocks. Gut contents of larvae (3) we examined were mostly fine organic particles with some filamentous algae and fine rock fragments. R E M A R K S Taxonomy and distribution of adults were reviewed by Denning (1958b), Wiggins et al. (1985), and by Wiggins and Erman (1987); hypotheses of phylogeny and biogeography were proposed by Wiggins and Wisseman (1992).

Farula jewetti (Oregon, Clackamas Co., 20 April 1964, R O M ) A , larva, lateral x26, detail of lateral filaments on segment n; B , head and thorax, dorsal; C , case, lateral x l l , portion cut away to show position of subterminal closure membrane for pupation; D , maxillae and labium, ventral; E , mandible, ventral 416

Uenoidae: F a r u l a 26.1

417

26.2

Genus

Neophylax

D I S T R I B U T I O N AND S P E C I E S This is a genus of North America and eastern Asia. Twenty-one species o f Neophylax are known on this continent: eastern species (17) occur w i t h i n the area from Newfoundland to Minnesota and south through Missouri to Georgia; western species (4) are widespread i n the mountains from Alaska to California. Larvae of North American species have been identified i n the literature by several workers; a key to eight eastern species was given by Flint (1960). Diagnostic characters for final-instar larvae o f Nearctic species were provided by Vineyard et al. (in press). MORPHOLOGY The head is elongate, and i n some species bears a median frontoclypeal tubercle. The pronotum is narrowed from the mid-point forward, and the anteromedian notch i n the mesonotum is prominent (B). A l l larvae i n this genus have single abdominal gills and i n many species a short lobate g i l l also occurs ventrally on segment I (A); chloride epithelia occur on segments III through V. The lateral fringe is w e l l developed, but lamellae are reduced, usually to a few on segment V I . Length of larva up to 15 mm. C A S E The larval case (C) is relatively short and thick; constructed of coarse rock fragments w i t h larger stones along each side, it resembles cases i n Goeridae. Length of larval case up to 15 m m . B I O L O G Y Larvae are confined to flowing waters, where different species are characteristic o f particular types or sections of streams; several species may occupy a stream system, occurring i n a consistent pattern of longitudinal zonation (Beam and Wiggins 1987; Vineyard et al., i n press). For the most part, larvae grow during autumn and winter months; i n spring and early summer final instars fasten their cases to rocks and seal off the openings, but remain quiescent i n prepupal diapause for a period ranging from a few weeks to six months before initiation o f metamorphosis; adults of these species emerge i n late summer and autumn. I n a few species i n which adults fly i n spring and early summer, larvae grow in summer and autumn, as in the eastern N. ornatus Banks and the western N. occidentis (Banks). Larvae of all species feed by grazing diatoms and fine organic particles from rocks, and they pupate i n large aggregations on the underside o f rocks. R E M A R K S The systematics of all species was reviewed and revised by Vineyard et al. (in press); hypotheses of phylogenetic relationships and biogeography were also proposed. Species i n eastern and western North America represent different lineages.

Neophylax

rickeri (Oregon, Benton Co., 11 A p r i l 1964, ROM)

A, larva, lateral x l 4 , tarsal claw enlarged; B, head and thorax, dorsal; C, case, ventral x8; D , mandible, dorsal; E, labrum, dorsal; F, head, ventral 418

Uenoidae: Neophylax 26.2

419

26.3

Genus

Neothremma

D I S T R I B U T I O N AND S P E C I E S Species of Neothremma are confined to western North America, where they are widespread throughout mountainous areas from British Columbia, Alberta, and Yukon south to Colorado and California; seven species are known. The larva of N. alicia Banks has been identified (Flint 1960); we have associated larvae for three species, and have made collections of larvae from many parts o f the range of the genus. M O R P H O L O G Y I n both Neothremma and Farula the short triangular ventral apotome barely separates the genae (D), which for the most part are closely appressed along the ventral ecdysial line of the head; there are paired sclerites on both the meso- and metasterna (E), although Neothremma larvae also have a median prothoracic sternellum (E). The anterior border o f the pronotum in Neothremma is convex i n dorsal aspect and somewhat serrate, and i n at least some species bears a row of short stout setae (B). The anterior margin o f each mesonotal sclerite is not evenly rounded but projects anterolaterally as an angulate corner, the two mesonotal sclerites meeting in a single median notch; the darkened posterolateral corner of each mesonotal sclerite is extended to approximately the mid-lateral point o f the sclerite (B). On the abdomen a lateral fringe o f small filaments is usually complete on segment II but reduced to the posterior half o f the segments on III-VII, and the anterior half bears forked lamellae (A); chloride epithelia occur ventrally on segments V and VI, and a field o f tiny spines is present on the intersegmental area between IV and v (A). Length of larva up to 9 m m . C A S E Larval cases in Neothremma (C) are only slightly stouter than those i n Farula. Constructed o f sand grains, the cases are covered outside as well as inside w i t h silk. Length o f larval case up to 14 m m . B I O L O G Y Larvae occur on rocks in small turbulent montane streams but, j u d g i n g by collections we have made, species o f Neothremma generally inhabit larger streams than Farula do. They graze on fine organic particles, diatoms, and other algae ( M u t t k o w s k i and Smith 1929; M e c o m 1972a). Larvae pupate in clusters on the lower surfaces of rocks. In a study o f the life cycle o f N. alicia i n Alberta by Ogilvie and Clifford (1986), larvae required two years to complete development; larvae passed the first winter as instar II, the second winter as instar v, then completed a prepupal stage of 1-3 weeks and a pupation period of an additional 1-3 weeks. R E M A R K S Taxonomy and distribution of adults of the species were reviewed by W i g gins et al. (1985); and hypotheses of phylogeny and biogeography were proposed by W i g gins and Wisseman (1992).

Neothremma alicia (Idaho, Idaho Co., 4 June 1968, ROM) A, larva, lateral x27, details of lateral line and spines of segments IV, v; B, head and thorax, dorsal, detail of anterior border of pronotum; C, case x l 4 ; D, head, ventral; E, thorax, ventral 420

Uenoidae: Neothremma 26.3

421

26.4

Genus

Oligophlebodes

D I S T R I B U T I O N AND S P E C I E S Oligophlebodes is an endemic Nearctic genus, with all seven species now known confined to western montane areas, ranging from Alaska, Yukon, and Alberta through South Dakota to California and New M e x i c o . Larvae have been identified i n the literature for O. minutus (Banks) and O. sierra Ross (Flint 1960); we have associated material for these species and for O. ruthae Ross, i n addition to many larval collections. M O R P H O L O G Y Larvae are readily recognized because the pronotum is variously modified by longitudinal ridges and depressions, and the dorsum of the head i n some species at least bears a marginal carina (B). Sclerites of the head and first two thoracic segments are uniform dark brown in colour and coarsely pebbled. Mandibles lack distinct teeth, and the ventral apotome is T-shaped as i n Neophylax (D). The anteromedian emargination of the mesonotal sclerites is not as prominent as i t is in Neophylax; metanotal sal setae lack a sclerite. A b d o m i n a l gills are single, and the lateral fringe is lacking; chloride epithelia occur ventrally on some segments (A). Length o f larva up to 7.5 m m . C A S E Larval cases are constructed of coarse rock fragments, and are strongly tapered and curved (C); the exterior is often irregular because relatively large pieces are incorporated. The silken membrane restricting the posterior opening of the case has an unusual eccentric opening. Length of larval case up to 8.5 m m . B I O L O G Y Larvae of Oligophlebodes are characteristic of mountain streams, frequently the most turbulent sections. I n the life cycle o f O. sigma M i l n e (Pearson and Kramer 1972), larvae developed from late autumn through to summer; prepupal diapause w i t h i n sealed cases, similar to Neophylax, was followed by metamorphosis w i t h m a x i m u m emergence o f adults i n August and September. Larvae fed actively upon upper rock surfaces during the day, but returned to the lower surfaces at night; digestive tracts contained green and brown algae, diatoms, and unidentifiable plant fragments. A n unusual tendency for diurnal downstream drift was recorded for O. sigma (Waters 1968). The life cycle o f O. zelti N i m m o was studied by Ogilvie and Clifford (1986) i n Alberta i n a stream where Neothremma alicia also occurred; eggs deposited i n gelatinous masses on the underside o f rocks hatched i n 21 days, and larvae overwintered under the ice as fourth instars, completing development to emerge the f o l l o w i n g year. Prepupae were not found, nor was evidence o f diapause. Food o f the larvae was mainly fine particulate organic matter w i t h diatoms. REMARKS

Taxonomy o f adults was summarized by Ross ( 1944).

Oligophlebodes sp. (California, Shasta Co., 19 June 1967, ROM) A, larva, lateral x l 9 , detail of tarsal claw; B, head and thorax, dorsal; C, case, lateral x l 3 ; D, ventral apotome of head, ventral 422

Uenoidae: O l i g o p h l e b o d e s

26.4

423

26.5 Genus Sericostriata A N D S P E C I E S Sericostriata contains a single uncommon species, S. surdickae Wiggins, Weaver, and Unzicker, known from Montana and Idaho. D I S T R I B U T I O N

Larvae are similar to Farula and Neothremma, but Sericostriata are readily distinguished by the angulate anterolateral corners of the pronotum and mesonotum (B). The ventral apotome of the head (E) is longer and separates the genae more than in related genera. The two mesonotal sclerites form a pair of anteromesal notches rather than a single median notch as in the other genera. The prosternum lacks sclerites ( H ) ; and the protarsi, mesotarsi, and protibiae are flattened dorsally ( F ) . Filaments of the lateral fringe of the abdomen are restricted to the posterior part of segments I I - V I ( A ) ; forked lamellae arise anterad of the filaments on segments I I - V I I . Chloride epithelium occurs ventrally only on V, and a pair of ovoid lateral protuberances are found on V I I I ( A ) ; a dark sclerite on I X bears four long setae (J). Length of larva up to 6 mm. M O R P H O L O G Y

The larval case ( C ) is constructed entirely of dark, tough silk, tapered and slightly curved, with longitudinal ridges, features for which the generic name Sericostriata was derived. Transverse banding in the case suggests that the colour of the silk differs between intermittent periods of case-building. The posterior opening is restricted by a peripheral flange of silk. Length of case up to 8 mm. C A S E

Larvae of S. surdickae occur on the upper surfaces of rocks in rapid streams, frequently in the hygropetric zone. We have occasionally collected them at the same sites as Neothremma. Collections indicate that at least two years may be required for completion of the life cycle.

B I O L O G Y

Taxonomy and distribution of adults and additional information on the larva were provided by Wiggins et al. (1985). R E M A R K S

Sericostriata surdickae (Idaho, Adams Co., 2 May 1981, R O M ) A , larva, lateral x30; B , head and thorax, dorsal, detail of labrum; C , case, lateral xl6; D , mandible, dorsal; E , head, ventral; F, fore leg, dorsal; G , trochantin and fore coxa, lateral; H , thorax and abdominal segment I, ventral; J, sclerite of segment I X , dorsal (From Canadian Entomologist) 424

Uenoidae: Sericostriata 26.5

425

This page intentionally left blank

Literature Cited

Anderson, N.H. 1967a. Life cycle of a terrestrial caddisfly, Philocasca demita (Trichoptera: Limnephilidae), in North America. Annals of the Entomological Society of America 60(2): 320-23 - 1967b. Biology and downstream drift of some Oregon Trichoptera. Canadian Entomologist 99(5): 507-21 - 1974a. Observations on the biology and laboratory rearing of Pseudostenophylax edwardsi (Trichoptera: Limnephilidae). Canadian Journal of Zoology 52(1): 7-13 - 1974b. The eggs and oviposition behaviour of Agapetus fuscipes Curtis (Trich., Glossosomatidae). Entomologist's Monthly Magazine 109: 129-31 Anderson, N.H., and Belnavis, D.L. 1991. Long-term rearing of the limnephilid caddisfly Clistoronia magnified. Proceedings of the Sixth International Symposium on Trichoptera, Poland, 1989, C. Tomaszewski (ed.), pp. 137-41. Poznan: Adam Mickiewicz University Press Anderson, N.H., and Bourne, J.R. 1974. Bionomics of three species of glossosomatid caddis flies (Trichoptera: Glossosomatidae) in Oregon. Canadian Journal of Zoology 52(3): 405-11 Anderson, N.H., and Grafius, E. 1975. Utilization and processing of allochthonous material by stream Trichoptera. Internationale Vereinigung fiir Theoretische und Angewandte Limnologie, Verhandlungen 19: 3083-88 Anderson, N.H., and Wold, J.L. 1972. Emergence trap collections of Trichoptera from an Oregon stream. Canadian Entomologist 104(2): 189-201 Arens, W. 1990. Wear and tear of mouth parts: a critical problem in stream animals feeding on epilithic algae. Canadian Journal of Zoology 68(9): 1896-1914 Armitage, B.J. 1991. Diagnostic atlas of the North American caddisfly adults. I. Philopotamidae (2nd ed.). Athens, A L : The Caddis Press Armitage, B.J., and Hamilton, S.W. 1990. Diagnostic atlas of the North American caddisfly adults. II. Ecnomidae, Polycentropodidae, and Xiphocentronidae. Athens, A L : The Caddis Press

427

Literature Cited Back, R.C. 1983. Larva and pupa of Oxyethira leonensis (Trichoptera: Hydroptilidae). Florida Entomologist 66: 389-92 Balduf, W.V. 1939. The Bionomics of Entomophagous Insects, pt. II. St Louis: John S. Swift Barlocher, F , and Kendrick, B . 1973. Fungi and food preferences o f pseudolimnaeus. A r c h i v fur Hydrobiologie 72(4): 501-16

Gammarus

1975. Assimilation efficiency o f Gammarus pseudolimnaeus (Amphipoda) feeding on fungal mycelium or autumn-shed leaves. Oikos 26: 55-59 Barnard, P.C., and Dudgeon, D . 1984. The larval morphology and ecology of a new species of Melanotrichia from Hong K o n g (Trichoptera: Xiphocentronidae). Aquatic Insects 6(4): 245-52

-

Beam, B . D . , and Wiggins, G.B. 1987. A comparative study of the biology of five species of Neophylax (Trichoptera: Limnephilidae) i n southern Ontario. Canadian Journal o f Zoology 65(7): 1741-54 Berg, C O . 1949. L i m n o l o g i c a l relations of insects to plants of the genus Potamogeton. Transactions o f the American Microscopical Society 68(4): 279-91 Bernhardt, S.A. 1966. Observations on case-building by Nemotaulius hostilis (Hagen) larvae (Trichoptera: Limnephilidae). Bulletin of the Brooklyn Entomological Society 59-60: 63-76 Berté, S.B., and Pritchard, G. 1986. The life histories of Limnephilus externus Hagen, Anabolia bimaculata (Walker), and Nemotaulius hostilis (Hagen) (Trichoptera, L i m nephilidae) i n a pond i n southern Alberta, Canada. Canadian Journal of Zoology 64(10): 2348-2356 Betten, C. 1902. The larva of the caddis fly, Molanna cinerea Hagen. Journal of the N e w York Entomological Society 10: 147-54 -

1934. The caddis flies or Trichoptera of N e w York State. Bulletin o f the New York State Museum 292

-

1950. The genus Pycnopsyche America 43(4): 508-22

(Trichoptera). Annals of the Entomological Society o f

Betten, C , and Mosely, M . E . 1940. The Francis Walker Types o f Trichoptera i n the British Museum. London: British Museum (Natural History) Bicchierai, M . C . , and Moretti, G.P. 1987. Prosternai horn and Gilson's gland i n certain limnephilid larvae. Proceedings o f the Fifth International Symposium on Trichoptera, Lyon, 1986, M . Bournaud and H . Tachet (eds.), pp. 3-9. The Hague: Junk Bjarnov, N . , and Thorup, J. 1970. A simple method for rearing running-water insects, w i t h some preliminary results. A r c h i v fur Hydrobiologie 67(2): 201-9 Blickle, R . L . 1979. Hydroptilidae (Trichoptera) of America north of M e x i c o . University of New Hampshire, Agricultural Experiment Station Bulletin 509 Blickle, R . L . , and Denning, D . G . 1977. N e w species and a new genus of Hydroptilidae (Trichoptera). Journal of the Kansas Entomological Society 50(2): 287-300 Boto§âneanu, L . 1956. Le d é v e l o p p e m e n t postembryonnaire, la biologie et la position s y s t é m a t i q u e d'un des Trichoptères les plus intéressants de la faune e u r o p é e n n e : Helicopsyche bacescui Orghidan et Boto§âneanu. Acta Societatis Zoologicae Bohemoslovenicae 20(4): 285-312 Boto§àneanu, L . , and Sykora, J. 1973. Sur quelques Trichoptères (Insecta: Trichoptera) de 428

,ITERATURE #ITED #UBA SDES S SCUBANO ROUMAINES #UBA PPž  "UCHAREST %DITURA !CADEMIEI 2EPUBLICII 3OCIALISTE 2OMANIA "OWLES $% )NPRESS! NEW SPECIES OF 4RICHOPTERA %CNOMIDAE FROM 4EXAS*OURNAL OF THE.EW 9ORK%NTOMOLOGICAL 3OCIETY "OWLES $% AND !LLEN 24 $ESCRIPTION OFTHE FEMALE OF 4RICHOPTERA 0SYCHOMYIIDAE  %NTOMOLOGICAL .EWS     "RAY 22 !TECHNIQUE TOAIDTAXONOMIC STUDIES ON4RICHOPTERA LARVAE %NTOMOLO GISTgS-ONTHLY -AGAZINE     "RICKENSTEIN # /BER DEN .ETZBAU DER ,ARVE VON , 4RI CHOPT 0OLYCENTROPIDAE  !BHANDLUNGEN "AYERISCHE !KADAMIE DER7ISSENSCHAFTEN NS    "RUSVEN -! AND 3COGGAN !# 3ARCOPHAGOUS HABITS OF 4RICHOPTERA LARVAE ON DEAD FISH %NTOMOLOGICAL .EWS     #  3  )  2  /  4HE )NSECTS OF!USTRALIA -ELBOURNE -ELBOURNE 5NIVERSITY 0RESS #HAPIN *7 3YSTEMATICS OF.EARCTIC 4RICHOPTERA "RACHYCENTRIDAE  0H$DISSERTATION #LEMSON 5NIVERSITY #HAPMAN $7 AND $EMORY 2, 3EASONAL CHANGES INTHE FOOD INGESTED BY AQUATIC INSECT LARVAE AND NYMPHS INTWO /REGON STREAMS%COLOGY     #HEN 9% 4HE LARVA AND PUPA OF -ORSE 4RICHOPTERA ,IM NEPHILIDAE WITH AKEY TODESCRIBED LARVAE OF .ORTH !MERICAN SPECIES OF !QUATIC )NSECTS     #LOUD 4* AND 3TEWART +7 3EASONAL FLUCTUATIONS AND PERIODICITY IN THEDRIFT OF EADDISFLY LARVAE 4RICHOPTERA INTHE "RAZOS 2IVER 4EXAS!NNALS OF THE %NTOMOLOGICAL 3OCIETY OF !MERICA     #OFFMAN 70 #UMMINS +7 AND 7UYCHECK *# %NERGY FLOW INA WOODLAND STREAM ECOSYSTEM ) 4ISSUE SUPPORT TROPHIC STRUCTURE OF THE AUTUMNAL COMMUNITY !RCHIV FUR (YDROBIOLOGIE     #ORBET 03 0ARTHENOGENESIS INCADDISFLIES 4RICHOPTERA #ANADIAN *OURNAL OF :OOL OGY     #ORBET 03 3CHMID % AND !UGUSTIN # ,  4HE 4RICHOPTERA OF 3T(ELENgS )SLAND -ONTREAL ) 4HE SPECIES PRESENT AND THEIR RELATIVE ABUNDANCE ATLIGHT#ANADIAN %NTO MOLOGIST     #UDNEY -$ AND7ALLACE *" ,IFE CYCLES MICRODISTRIBUTION AND PRODUCTION DYNAMICS OF SIX SPECIES OFNET SPINNING CADDISFLIES IN ALARGE SOUTHEASTERN 53! RIVER(OLARCTIC %COLOGY    #UMMINS +7 &ACTORS LIMITING THE MICRODISTRIBUTION OF LARVAE OF THE CADDISFLIES (AGEN AND 7ALKER IN A-ICHIGAN STREAM 4RICHOPTERA ,IMNEPHILIDAE  %COLOGICAL -ONOGRAPHS    

4ROPHIC RELATIONS OF AQUATIC INSECTS !NNUAL 2EVIEW OF%NTOMOLOGY    ( AND ,AFONT - #YCLES VITAUX ET PRODUCTION DES S DANS LESMOUSSES DgEAU COURANTE !NNALES DE,IMNOLOGIE     $ENIS # ,ARVAL AND IMAGINAI DIAPAUSE IN,IMNEPHILIDAE 0ROCEEDINGS OF THE 3ECOND )NTERNATIONAL 3YMPOSIUM ON4RICHOPTERA 2EADING  -)#RICHTON PP  4HE (AGUE *UNK 

Literature Cited Denning, D . G . 1937. The biology o f some Minnesota Trichoptera. Transactions of the American Entomological Society 63: 17-43 -

1956. Trichoptera. In Aquatic Insects of California, R . L . Usinger (ed.), pp. 237-70. Berkeley and Los Angeles: University o f California Press

-

1958a. New western Trichoptera. Pan-Pacific Entomologist 34(2): 93-98

-

1958b. The genus Farula (Trichoptera: Limnephilidae). Annals o f the Entomological Society o f America 51(6): 531-35

-

1964. The genus Homophylax (Trichoptera: Limnephilidae). Annals of the Entomological Society o f America 57(2): 253-60

-

1970. The genus Psychoglypha 102(1): 15-30

-

1973. New species o f Trichoptera. Pan-Pacific Entomologist 49(2): 132-43 1975. New species o f Trichoptera from western North America. Pan-Pacific Entomologist 51(4): 318-26

(Trichoptera: Limnephilidae). Canadian Entomologist

Denning, D.G., and B l i c k l e , R . L . 1972. A review of the genus Ochrotrichia (Trichoptera: Hydroptilidae). Annals o f the Entomological Society o f America 65(1): 141-51 Denning, D.G., and Sykora, J. 1966. New North American Trichoptera. Canadian Entomologist 98(11): 1219-26 Dodds, G.S., and Hisaw, F.L. 1924. Ecological studies o f aquatic insects. II. Size o f respiratory organs in relation to environmental conditions. Ecology 5(3): 262-71 - 1925. Ecological studies on aquatic insects. I I I . Adaptations o f caddisfly larvae to swift streams. Ecology 6(2): 123-37 Edington, J . M . 1964. The taxonomy of British polycentropid larvae (Trichoptera). Proceedings of the Zoological Society, London, 143(2): 281-300 Edwards, S.W. 1956. Two new species o f Trichoptera from Tennessee. Journal of the Tennessee Academy o f Science 31(1): 3-7 - 1961. The immature stages o f Xiphocentron mexico (Trichoptera). Texas Journal o f Science 13(1): 51-56 - 1966. A n annotated list o f the Trichoptera of middle and west Tennessee. Journal of the Tennessee Academy o f Science 41(4): 116-28 Edwards, S.W., and A r n o l d , C.R. 1961. The caddis flies o f the San Marcos River. Texas Journal of Science 13(4): 398-415 Elkins, W . A . 1936. The immature stages o f some Minnesota Trichoptera. Annals of the Entomological Society o f America 29(4): 656-81 Elliott, J.M. 1969. Life history and biology o f Sericostoma personatum Spence (Trichoptera). O i k o s 2 0 : 110-18 - 1970. The diel activity patterns of caddis larvae (Trichoptera). Journal of the Zoological Society o f L o n d o n 160(3): 279-90 - 1971. The life history and biology o f Apatania muliebris McLachlan (Trichoptera). Entomologist's Gazette 22: 245-51 Ellis, R.J. 1978. Seasonal abundance and distribution o f adult caddisflies o f Sashin Creek, Baranof Island, Southeastern Alaska. Pan-Pacific Entomologist 54(3): 199-206 English, W.R., and Hamilton, S.W. 1986. The larva o f Ochrotrichia arizonica (Trichoptera: Hydroptilidae) w i t h notes on distribution and geographic variation. Journal o f the Kansas Entomological Society 59(3): 474-79 430

Literature Cited Erman, N . A . 1981. Terrestrial feeding migration and life history of the stream-dwelling caddisfly Desmona bethula (Trichoptera: Limnephilidae). Canadian Journal of Zoology 59(9): 1658-65 Fairchild, W . L . , and Wiggins, G.B. 1989. Immature stages and biology of the North American caddisfly genus Phanocelia (Trichoptera: Limnephilidae). Canadian Entomologist 121(6): 515-19 Feldmeth, C.R. 1970. The respiratory energetics of two species of stream caddis f l y larvae in relation to water flow. Comparative Biochemistry and Physiology 32: 193— 202 Fischer, F.C.J. 1960-73. Trichopterorum Catalogus. Amsterdam: Nederlandsche Entomologische Vereeniging (vol. 1, 1960; v o l . 2, 1961; v o l . 3, 1962; v o l . 4, 1963; v o l . 5, 1964; v o l . 6, 1965; v o l . 7, 1966; v o l . 8, 1967; v o l . 9, 1968; v o l . 10, 1969; v o l . 11, 1970; v o l . 12, 1971; v o l . 13, 1972a; v o l . 14, 1972b; v o l . 15, 1973) Flint, O.S. 1956. The life history and biology of the genus Frenesia (Trichoptera: L i m nephilidae). Bulletin o f the Brooklyn Entomological Society 51(4, 5): 93-108 1957. Description o f the immature stages o f Drusinus uniformis Betten (Trichoptera: Limnephilidae). Bulletin of the B r o o k l y n Entomological Society 52(1): 1-4 - 1958. The larva and terrestrial pupa o f Ironoquia parvula (Trichoptera, Limnephilidae). Journal of the New York Entomological Society 66: 59-62 -

1959. The immature stages of Lype diversa (Banks) (Trichoptera, Psychomyiidae). B u l letin o f the B r o o k l y n Entomological Society 54(2): 44-47 - 1960. Taxonomy and biology of Nearctic limnephilid larvae (Trichoptera), w i t h special reference to species i n eastern United States. Entomologica Americana, n.s. 40: 1-117

-

-

1961a. The immature stages of the Arctopsychinae occurring i n eastern North America (Trichoptera: Hydropsychidae). Annals of the Entomological Society of America 54(1): 5-11

-

1961 b. The presumed larva of Himalopsyche phryganea (Ross) (Trichoptera: Rhyacophilidae). Pan-Pacific Entomologist 37(4): 199-202 1962a. The immature stages of Paleagapetus celsus Ross (Trichoptera: Hydroptilidae). Bulletin of the B r o o k l y n Entomological Society 57(2): 4 0 - 4 4 1962b. The immature stages o f Matrioptila jeanae (Ross) (Trichoptera: Glossosomatidae). Journal of the New York Entomological Society 70: 64-67 1962c. Larvae of the caddis f l y genus Rhyacophila i n eastern North America (Trichoptera: Rhyacophilidae). Proceedings of the United States National Museum 113(3464): 465-93 1963. Studies of Neotropical caddis flies, I : Rhyacophilidae and Glossosomatidae (Trichoptera). Proceedings o f the United States National Museum 114(3473): 453-78 1964a. Notes on some Nearctic Psychomyiidae w i t h special reference to their larvae (Trichoptera). Proceedings of the United States National Museum 115(3491): 467-81 1964b. The caddisflies (Trichoptera) of Puerto Rico. University o f Puerto Rico, A g r i culture Experiment Station, Technical Paper 40 1965. N e w species o f Trichoptera from the United States. Proceedings of the Entomological Society of Washington 67(3): 168-76 1966. Notes on certain Nearctic Trichoptera i n the Museum of Comparative Zoology. Proceedings o f the United States National Museum 118(3530): 373-89

-

-

431

Literature Cited -

1967a. Studies o f Neotropical caddis flies, IV. N e w species from Mexico and Central America. Proceedings o f the United States National Museum 123(3608): 1-24

-

1967b. Studies o f Neotropical caddis flies, V Types o f the species described by Banks and Hagen. Proceedings of the United States National Museum 123(3619): 1-37

-

1967c. Studies o f Neotropical caddis flies, V I : On a collection from northwestern M e x i c o . Proceedings o f the Entomological Society o f Washington 69(2): 162-76

-

1967d. The first record o f the Paduniellini in the N e w W o r l d (Trichoptera: Psychomyiidae). Proceedings o f the Entomological Society o f Washington 69(4): 310-11

-

1968a. Bredin-Archbold-Smithsonian biological survey o f Dominica. 9. The T r i choptera (caddisflies) o f the Lesser Antilles. Proceedings of the United States National Museum 125(3665): 1-86

-

1968b. The caddisflies of Jamaica (Trichoptera). B u l l e t i n o f the Institute o f Jamaica, Science Series 19 1970. Studies o f Neotropical caddisflies, x : Leucotrichia and related genera from North and Central America (Trichoptera: Hydroptilidae). Smithsonian Contributions to Z o o l ogy 60

-

1972. Studies o f Neotropical caddisflies, x m : the genus Ochrotrichia from M e x i c o and Central America (Trichoptera: Hydroptilidae). Smithsonian Contributions to Zoology 118 - 1973. Studies of Neotropical caddisflies, X V I : the genus Austrotinodes (Trichoptera: Psychomyiidae). Proceedings of the Biological Society o f Washington 86(11): 127-42 - 1974a. Studies o f Neotropical caddisflies, X V I I : the genus Smieridea from North and Central America (Trichoptera: Hydropsychidae). Smithsonian Contributions to Zoology 167 - 1974b. The genus Culoptila Mosely i n the United States, w i t h two new combinations (Trichoptera: Glossosomatidae). Proceedings of the Entomological Society o f Washington 76(3): 284 - 1974c. The Trichoptera o f Surinam; studies o f Neotropical caddisflies, XV. Studies on the Fauna o f Suriname and Other Guy anas, 55 - 1984. The genus Brachycentrus in North America, w i t h a proposed phylogeny o f the genera o f Brachycentridae (Trichoptera). Smithsonian Contributions to Zoology 398 Flint, O.S., and Bueno-Soria, J. 1982. Studies of Neotropical caddisflies, X X X I I : the immature stages o f Macronema variipenne Flint and Bueno, w i t h the division of Macronema by the resurrection o f Macrostemum (Trichoptera: Hydropsychidae). Proceedings o f the Biological Society o f Washington 95(2): 358-70 Flint, O.S., and Harris, S.C. 1991. Studies o f Neotropical caddisflies X L l l : Taraxitrichia amazonensis, a new genus and species o f microcaddisfly from Venezuela (Trichoptera: Hydroptilidae). Proceedings o f the Sixth International Symposium on Trichoptera, Poland, 1989, C. Tomaszewski (ed.), pp. 411-14. Poznan: A d a m M i c k i e w i c z University Press Flint, O.S., and Herrmann, S.J. 1976. The description of, and environmental characterization for, a new species o f Ochrotrichia from Colorado (Trichoptera: Hydroptilidae). Annals o f the Entomological Society o f America 69(5): 894-98 Flint, O.S., M c A l p i n e , J.F., and Ross, H . H . 1987. A revision o f the genus Leptonema

-

432

Literature Cited G u é r i n (Trichoptera: Hydropsychidae: Macronematinae). Smithsonian Contributions to Zoology 450. Flint, O.S., and Wallace, J.B. 1980. Studies o f Neotropical caddisflies XXV: the immature stages o f Blepharopus diaphanus and Leptonema columbianum (Trichoptera: Hydropsychidae). Proceedings o f the Biological Society o f Washington 93(1): 178-93 Fox, H . M . , and Sidney, J. 1953. The influence o f dissolved oxygen on the respiratory movements o f caddis larvae. Journal o f Experimental Biology 30(2): 235-37 Frania, H.E., and Wiggins, G.B. In press. Analysis o f morphological and behavioural evidence for the phylogeny and higher classification o f Trichoptera. Royal Ontario Museum, Life Sciences Contributions 160 Fremling, C R . 1960. Biology and possible control o f nuisance caddisflies o f the upper Mississippi River. Iowa State University o f Science and Technology, Research Bulletin 483: 856-79 Frommer, S.I., and Sublette, J.E. 1971. The Chironomidae (Diptera) o f the Philip L . B o y d Deep Canyon Desert Research Center, Riverside Co., California. Canadian Entomologist 103(3): 414-23 Fuller, E.R., and Wiggins, G.B. 1987. A new species o f Molannodes from Hokkaido, Japan (Trichoptera: Molannidae). Aquatic Insects 9(1): 39-43 Fuller, H . , Tomaszewski, C , and Marciniak, B . 1991. The homological relations in the musculature o f the protuberances o f the first abdominal segment in caddis larvae (Trichoptera). Proceedings o f the Sixth International Symposium on Trichoptera, Poland, 1989, C. Tomaszewski (ed.), pp. 291-98. Poznan: A d a m M i c k i e w i c z University Press Fuller, R . L . , and Mackay, R.J. 1980. Feeding ecology o f Hydropsyche (Trichoptera: Hydropsychidae) i n southern Ontario. Canadian Journal o f Zoology 58(12): 2239-51 Gall, W . K . , and Wiggins, G.B. In press. Phylogeny and classification o f the families o f the Limnephiloidea (Trichoptera).Bulletin o f the Buffalo Society o f Natural Sciences 35 - In preparation. Phylogeny and classification o f the caddisfly family Goeridae (Trichoptera). Gallepp, G.W. 1974a. D i e l periodicity in the behaviour o f the caddisfly, Brachycentrus americanus (Banks). Freshwater B i o l o g y 4(2): 193-204 - 1974b. Behavioral ecology o f Brachycentrus occidentalis Banks during the pupation period. Ecology 55(6): 1283-94 Gibbs, D . G . 1968. The larva, dwelling-tube and feeding o f a species o f Protodipseudopsis (Trichoptera: Dipseudopsidae). Proceedings o f the Royal Entomological Society o f London ( A ) , 4 3 ( 4 - 6 ) : 73-79 Givens, D.R., and Smith, S.D. 1980. A synopsis o f western Arctopsychinae (Trichoptera: Hydropsychidae). Melanderia 35: 1-24 Glime, J . M . 1968. Ecological observations on some bryophytes in Appalachian mountain streams. Castanea 33: 300-25 Glover, J.B. 1993. The taxonomy and biology o f the larvae o f the North American caddisflies in the genera Triaenodes and Ylodes (Trichoptera: Leptoceridae). Ph.D. dissertation, Department o f Biology, University o f Louisville Gordon, A . E . 1974. A synopsis and phylogenetic outline o f the Nearctic members of Cheumatopsyche. Proceedings o f the Academy o f Natural Sciences Philadelphia 126(9): 117-60 433

Literature Cited Gotceitas, V. 1985. Formation of aggregations by overwintering fifth instar Dicosmoecus at ripes larvae (Trichoptera). Oikos 44: 313-18 Gotceitas, V., and Clifford, H.F. 1983. The life history of Dicosmoecus at ripes (Hagen) (Limnephilidae: Trichoptera) in a Rocky Mountain stream of Alberta, Canada. Canadian Journal of Zoology 61(3): 586-96 Haddock, J.D. 1977. The biosystematics of the caddis fly genus Nectopsyche in North America with emphasis on the aquatic stages. American Midland Naturalist 98(2): 3 8 2 421 Hamilton, S.W. 1985. The larva and pupa of Beraea gorteba Ross (Trichoptera: Beraeidae). Proceedings of the Entomological Society of Washington 87: 783-89 Hanna, H.M. 1960. Methods of case-building and repair by larvae of caddis flies. Proceedings of the Royal Entomological Society, London (A), 35(7-9): 97-106 Hansell, M.H. 1968a. The selection of house building materials by the caddis fly larva, Agapetus fuscipes (Curtis). Revue du Comportement Animal 2: 9 1 - 1 0 2 - 1968b. The house building behaviour of the caddis-fly larva Silo pallipes Fabricius, pts. 1-3. Animal Behaviour 16(4): 5 5 8 - 8 4 - 1972. Case building behaviour of the caddis fly larva, Lepidostoma hirtum. Journal of the Zoological Society of London 167(2): 179-92 - 1974. Regulation of building unit size in the house building of the caddis larva Lepidostoma hirtum. Animal Behaviour 22(1): 133-43 Harris, S.C., and Holzenthal, R.W. 1993. Phylogeny of the species groups of Alisotrichia sensu lato, with the description of a new species from Costa Rica (Trichoptera: Hydroptilidae). Proceedings of the Seventh International Symposium on Trichoptera, Sweden, 1992, C. Otto (ed.). Leiden: Backhuys Publishers Harris, T.L., and Lawrence, T.M. 1978. Environmental requirements and pollution tolerance of Trichoptera. United States Environmental Protection Agency Report 600/4—78063 Hauer, F.R., and Stanford, J.A. 1982. Bionomics of Dicosmoecus gilvipes (Trichoptera: Limnephilidae) in a large western montane river. American Midland Naturalist 108(1): 81-87 - 1986. Ecology and co-existence of two species of Brachycentrus (Trichoptera) in a Rocky Mountain river. Canadian Journal of Zoology 64(7): 1469-74 Hickin, N.E. 1967. Caddis Larvae. London: Hutchinson Hiley, P.D. 1969. A method of rearing Trichoptera larvae for taxonomic purposes. Entomologist's Monthly Magazine 105(1265-67): 278-79 Hill-Griffin, A.L. 1912. New Oregon Trichoptera. Entomological News 23(1): 17-21 Hinton, H.E. 1949. On the function, origin, and classification of pupae. Proceedings and Transactions of the South London Entomological and Natural History Society 1947-48: 111-54 - 1950. A trichopterous larva with a chelate front leg. Proceedings of the Royal Entomological Society, London (A), 25(4-6): 6 2 - 6 5 - 1971. Some neglected phases in metamorphosis. Proceedings of the Royal Entomological Society, London (C), 35: 5 5 - 6 4 Hodkinson, I.D. 1975. A community analysis of the benthic insect fauna of an abandoned beaver pond. Journal of Animal Ecology 44(2): 533-51 434

Literature Cited Holzenthal, R.W. 1982. The caddisfly genus Setodes in North America (Trichoptera: Leptoceridae). Journal o f the Kansas Entomological Society 55(2): 253-71 Hudson, P.L., Morse, J.C., and Voshell, J.R. 1981. Larva and pupa o f Cernotina spicata. Annals o f the Entomological Society o f America 74(5): 516-19 Huryn, A . D . 1989. Identity of the hydropsychid larva known as 'OropsycheT: the immature stages of Homoplectra flinti Weaver. Journal o f the North American Benthological Society 8(1): 112-16 Huryn, A . D . , and Wallace, J.B. 1984. New eastern Nearctic limnephilid (Trichoptera) with unusual zoogeographical affinities. Annals o f the Entomological Society o f America 77(3): 284-92 1985. Life history and production of Goerita semata Ross (Trichoptera: Limnephilidae) in the southern Appalachian Mountains. Canadian Journal o f Zoology 63(10): 2604-11 Hynes, H . B . N . 1970. The Ecology o f Running Waters. Toronto: University of Toronto Press Ito, T. 1991. Morphology and bionomics o f Palaeagapetus flexus n. sp. from northern Japan (Trichoptera: Hydroptilidae). Proceedings o f the Sixth International Symposium on Trichoptera, Poland, 1989, C. Tomaszewski (ed.), pp. 419-26. Poznan: A d a m M i c k iewicz University Press Jaag, O., and A m b i i h l , H . 1964. The effect o f the current on the composition o f biocoenoses i n flowing water streams. In Advances i n Water Pollution Research; Proceedings of the International Conference, London, 1962, B . A . Southgate (ed.), pp. 31-44. Oxford: Pergamon Press Jansson, A . , and Vuoristo, T. 1979. Significance o f stridulation in larval Hydropsychidae (Trichoptera). Behaviour 7 1 : 167-86 Johansson, A . , Nilsson, A . N . , and Svensson, B.W. 1991. Larval morphology, habit and distribution o f Limnephilus diphyes (Trichoptera, Limnephilidae). Entomologisk T i d skrift 112: 19-25 Johnstone, G.W. 1964. Stridulation by larval Hydropsychidae (Trichoptera). Proceedings of the Royal Entomological Society, London ( A ) , 39(10-12): 146-50 Kelley, R.W. 1984. Phylogeny, morphology and classification o f the micro-caddisfly genus Oxyethira Eaton (Trichoptera: Hydroptilidae). Transactions of the American Entomological Institute 110: 435-63 Kerr, J.D., and Wiggins, G.B. 1993. Larval taxonomy in North American Lepidostomatidae. Proceedings o f the Seventh International Symposium on Trichoptera, Sweden, 1992, C. Otto (ed.), pp. 117-21. Leiden: Backhuys Publishers Kerr, J.D., and Wiggins, G.B. 1995. Lateral line systems in larval and pupal Trichoptera. Zoological Journal o f the Linnaean Society K i m m i n s , D.E., and Denning, D . G . 1951. The McLachlan types o f North American T r i choptera i n the British Museum. Annals o f the Entomological Society o f America 44(1): 111-40 Krivda, W.V. 1961. Notes on the distribution and habitat of Chilostigma areolatum (Walker) i n Manitoba (Trichoptera: Limnephilidae). Journal o f the New York Entomological Society 69: 68-70 Lea, I . 1834. Observations on the Naiades and descriptions of new species of that and other families. Transactions o f the American Philosophical Society, n.s. 4: 63-121 -

435

Literature Cited L e h m k u h l , D . M . 1970. A North American trichopteran larva which feeds on freshwater sponges (Trichoptera: Leptoceridae; Porifera: Spongillidae). American M i d l a n d Naturalist 84(1): 278-80 Lehmkuhl, D . M . , and Kerst, C D . 1979. Zoogeographical affinities and identification of central A r c t i c caddisflies (Trichoptera). Musk-Ox 25: 12-28 Lepneva, S.G. 1956. Morphological relationships o f the subfamilies

Psychomyinae,

Ecnominae (Trichoptera, Annulipalpia) in the preimaginal stages. Entomologicheskoye Obozrenie 35(1): 8-27. [ I n Russian] - 1964. Fauna SSSR, Rucheiniki, v o l . 2, no. 1. L i c h i n k i i kukolki podotryada k o l ' chatoshchupikovykh. Zoologicheskii Institut Akademii Nauk SSSR, n.s. 88. [In Russian. Translated into English as: Fauna of the U.S.S.R.; Trichoptera, v o l . 2, no. 1. Larvae and Pupae of Annulipalpia. Published by the Israel Program for Scientific Translations, 1970] - 1966. Fauna SSSR, Rucheiniki, v o l . 2, no. 2. L i c h i n k i i kukolki podotryada tsel'noshchupikovykh. Zoologicheskii Institut A k a d e m i i Nauk SSSR, n.s. 95. [In Russian. Translated into English as: Fauna of the U.S.S.R.; Trichoptera, v o l . 2, no. 2. Larvae and Pupae of Integripalpia. Published by the Israel Program for Scientific Translations, 1971] Levanidova, I . M . 1967. Materialy po faune rucheinikov (Trichoptera) Sibiri i Dalnego Vostoka. Entomologicheskoe Obozrenie, 46: 793-98 [In Russian. Translated into English as: Data on the caddisfly (Trichoptera) fauna o f Siberia and the Far East. Entomological Review 46(4): 467-70 (1967)] -

1975. Rucheiniki Kamchatskogo Poluostrova (ekologo-faunisticheskii obzor). Izvestia Tikhookeanskogo Nauchno-Issledovatelskogo Instituta Rybnogo Khozyaistva i Okeanografii 97: 83-114. [ I n Russian. The Caddisflies (Trichoptera) of Kamchatka (an ecological-faunistic outline). Bulletin of the Pacific Scientific Institute o f Fisheries and Oceanography] L l o y d , J.T. 1915. Notes on Astenophylax argus Harris (Trichoptera). Journal of the New York Entomological Society 23(1): 57-60 - 1921. The biology o f N o r t h American caddis f l y larvae. Bulletin o f the L l o y d Library 21 M c A u l i f f e , J.R. 1982. Behavior and life history o f Leucotrichia pictlpes (Banks) (Trichoptera: Hydroptilidae) w i t h special emphasis on case reoccupancy. Canadian Journal of Zoology 60(7): 1557-61 - 1984. Competition for space, disturbance, and the structure of a benthic stream community. Ecology 65(3): 894-908 McGaha, Y.J. 1952. The limnological relations of insects to certain aquatic flowering plants. Transactions o f the American Microscopical Society 71(4): 355-81 Mackay, R.J. 1968. Seasonal variation in the structure of stream insect communities. M.Sc. thesis, M c G i l l University - 1969. Aquatic insect communities of a small stream on M o n t St. Hilaire, Q u é b e c . Journal o f the Fisheries Research Board o f Canada 26(5): 1157-83 - 1972. Temporal patterns in life history and flight behaviour o f Pycnopsyche gentilis, P. luculenta, and P. scabripennis (Trichoptera: Limnephilidae). Canadian Entomologist 104(11): 1819-35 436

Literature Cited -

1979. Life history patterns of some species o f Hydropsyche (Trichoptera: Hydropsychidae) i n southern Ontario. Canadian Journal of Zoology 57(5): 963-75

-

1984. Life history patterns of Hydropsy che hronta and H. morosa (Trichoptera: Hydropsychidae) in summer-warm rivers o f southern Ontario. Canadian Journal o f Zoology 62(2): 271-75

Mackay, R.J., and Kalff, J. 1973. Ecology o f two related species of caddis fly larvae i n the organic substrates of a woodland stream. Ecology 54(3): 499-511 Mackay, R.J., and Wiggins, G.B. 1979. Ecological diversity in Trichoptera. Annual Review of Entomology 24: 185-208 Mackereth, J.C. 1956. Taxonomy of the larvae of the British species o f the sub-family Glossosomatinae (Trichoptera). Proceedings of the Royal Entomological Society, L o n don ( A ) , 31(10-12): 167-72 MacLean, S.F., and Pitelka, F.A. 1971. Seasonal patterns of abundance of tundra arthropods near Barrow. Arctic 24: 19-40 Majecki, J., and Tomaszewski, C. 1991. The role of case in the process of gas exchange in some Trichoptera species. Proceedings o f the Sixth International Symposium on T r i choptera, Poland, 1989, C. Tomaszewski (ed.), pp. 2 1 7 - 2 1 . Poznan: A d a m M i c k i e w i c z University Press Malicky, H . 1973. Trichoptera (Kôcherfliegen). Handbuch der Zoologie 4(2) -

1993. First speculations on the size of areas and the numbers of species of caddisflies (Trichoptera) i n Southeastern Asia. Proceedings of the Seventh International Symposium on Trichoptera, Sweden, 1992, C. Otto (ed.), p. 92. Leiden: Backhuys Publishers

Manuel, K . L . , and Braatz, D . A . 1984. The life cycle and fifth instar larval description o f Triaenodes taenia (Leptoceridae). Proceedings of the Fourth International Symposium on Trichoptera, Clemson, S.C., 1983, J.C. Morse (ed.), pp. 213-17. The Hague: Junk Manuel, K . L . , and Folsom, T.C. 1982. Instar sizes, life cycles, and food habits o f five Rhyacophila (Trichoptera: Rhyacophilidae) species from the Appalachian Mountains of South Carolina, U.S.A. Hydrobiologia 97: 281-85 Manuel, K . L . , and N i m m o , A.P. 1984. The caddisfly genus Ylodes i n North America ( T r i choptera: Leptoceridae). Proceedings o f the Fourth International Symposium on T r i choptera, Clemson, S.C., 1983, J.C. Morse (ed.), pp. 219-24. The Hague: Junk Marlier, G. 1952. Recherches hydrobiologiques dans les rivières du Congo Oriental: T r i choptères, Sericostomatidae et Dipseudopsinae. Annales du M u s é e Royal Congo Belge, Tervuren, 8(21): 9-65 -

1961. Hydropsychidae du K i v u . Revue de Zoologie et de Botanique Africaines 63 ( 1 - 2 ) : 158-212

-

1962. Genera des Trichoptères de l'Afrique. Annales du M u s é e Royal de l ' A f r i q u e Centrale, Tervuren, Science Zoologique 109

-

1964. Trichoptères de l ' A m a z o n i e recueillis par le Professeur H . Siolo. M é m o i r e s de l'Institut royale des Sciences naturelles de Belgique, d e u x i è m e série, fasc. 76 Marshall, J.E. 1979. A review o f the genera of the Hydroptilidae (Trichoptera). Bulletin of the British Museum (Natural History), Entomology Series 39(3): 135-239

Martinson, R.J., and Ward, J.V. 1982. L i f e history and ecology o f Hesperophylax occidentalis (Banks) (Trichoptera: Limnephilidae) from three springs i n the Piceance Basin, Colorado. Freshwater Invertebrate B i o l o g y 1(3): 41-47 437

Literature Cited Martynov, A.V. 1924. Prakticheskaya entomologie, vyp.5. Rucheiniki, [In Russian. Practical entomology, vol. 5. Trichoptera.] Leningrad: Gosudarstvennoe Izdatelstvo - 1930. On the trichopterous fauna of China and eastern Tibet. Proceedings of the Zoological Society, London 1930(5): 65-112 Mathis, M.L., and Bowles, D.E. 1989. A new microcaddisfly genus (Trichoptera: Hydroptilidae) from the interior Highlands of Arkansas. Journal of the New York Entomological Society 97: 187-91 - 1994. A description of the immature stages of Paduniella nearctica (Trichoptera: Psychomyiidae) with notes on its biology. Journal of the New York Entomological Society 102(3): 361-66 Matsuda, R. 1965. Morphology and evolution of the insect head. Memoirs of the American Entomological Institute 4 Mecom, J.O. 1972a. Feeding habits of Trichoptera in a mountain stream. Oikos 23: 401-7 - 1972b. Productivity and distribution of Trichoptera larvae in a Colorado mountain stream. Hydrobiologia 40: 151-76 Mecom, J.O., and Cummins, K.W. 1964. A preliminary study of the trophic relationships of the larvae of Brachycentrus americanus (Banks) (Trichoptera: Brachycentridae). Transactions of the American Microscopical Society 83(2): 233-43 Merrill, D. 1965. The stimulus for case-building activity in caddis-worms (Trichoptera). Journal of Experimental Zoology 158(1): 123-30 - 1969. The distribution of case recognition in ten families of caddis larvae (Trichoptera). Animal Behaviour 17(3): 486-93 Merrill, D., and Wiggins, G B . 1971. The larva and pupa of the caddisfly genus Setodes in North America (Trichoptera: Leptoceridae). Royal Ontario Museum, Life Sciences Occasional Papers 19 Mickel, C.E., and Milliron, H.E. 1939. Rearing the caddice fly, Limnephilus indivisus Walker and its hymenopterous parasite Hemiteles biannulatus Grav. Annals of the Entomological Society of America 32(3): 575-80 Milne, M.J. 1938. Case-building in Trichoptera as an inherited response to oxygen deficiency. Canadian Entomologist 70(9): 177-80 Minckley, W.L. 1963. The ecology of a spring stream, Doe Run, Meade County, Kentucky. Wildlife Monographs 11 Moretti, G. 1942. Studii sui tricotteri: XV. Comportamento del Triaenodes bicolor Curt. (Trichoptera - Leptoceridae). Bolletino di Zoologia Agraria Bachicoltura, Milano, 11: 89-131 Morse, J.C. 1972. The genus Nyctiophylax in North America. Journal of the Kansas Entomological Society 45(2): 172-81 - 1975. A phylogeny and revision of the caddisfly genus Ceraclea (Trichoptera, Leptoceridae). Contributions of the American Entomological Institute 11(2): 1-97 - 1981. A phylogeny and classification of family group taxa of Leptoceridae (Trichoptera). Proceedings of the Third International Symposium on Trichoptera, Perugia, 1980, G.P. Moretti (ed.), pp. 257-64. The Hague: Junk Morse, J . C , and Barr, C.B. 1990. Unusual caddisfly (Trichoptera) fauna of Schoolhouse Springs, Louisiana, with description of a new species of Diplectrona (Hydropsychidae). Proceedings of the Entomological Society of Washington 92(1): 58-65 438

Literature Cited Morse, J.C., and Holzenthal, R.W. 1984. Trichoptera Genera. In A n Introduction to the Aquatic Insects of North America, 2nd edition revised, R.W. Merritt and K . W . C u m mins (eds.), pp. 312-47. Dubuque, Iowa: Kendall Hunt M o u l t o n , S.R., Stewart, K . W . , and Young, K . L . 1994. New records, distribution, and taxonomic status o f some northern Arizona caddisflies (Trichoptera). Entomological News 105(3): 164-74 Murphy, H.E. 1919. Observations on the egg-laying of the caddice-fly Brachycentrus nigrisoma Banks, and on the habits of the young larvae. Journal of the New York Entomological Society 27: 154-59 M u t t k o w s k i , R.A., and Smith, G . M . 1929. The food of trout stream insects in Yellowstone National Park. Roosevelt W i l d Life Annals 2(2): 241-63 Neave, F. 1933. Ecology of two species of Trichoptera in Lake Winnipeg. Internationale Revue der gesamten Hydrobiologie und Hydrographie 29(1/2): 17-28 Neboiss, A . 1993. Revised definitions of the genera Nyctiophylax Brauer, and Paranyctiophylax Tsuda (Trichoptera: Polycentropodidae). Proceedings o f the Seventh International Symposium on Trichoptera, Sweden, 1992, C. Otto (ed.), 107-11. Leiden: Backhuys Publishers Needham, J.G. 1902. A probable new type of hypermetamorphosis. Psyche 9(316): 375-78 Nielsen, A . 1942. Û b e r die Entwicklung und Biologie der Trichopteren m i t besonderer Berucksichtigung der Quelltrichopteren Himmerlands. A r c h i v fiir Hydrobiologie, Supplement Band 17: 255-631 - 1943a. Apatidea auricula Forsslund from a Norwegian mountain lake; description of the imago and notes on the biology. Entomologicke Meddelelser 23: 18-30 - 1943b. Trichopterologische Notizen. Videnskabelige Meddelelser fra Dansk Naturhistorisk Forening 107: 105-20 - 1948. Postembryonic development and biology o f the Hydroptilidae. Kongelige Danske Videnskabernes Selskab, Biologiske Skrifter 5(1) - 1950. Notes on the genus Apatidea MacLachlan, with descriptions o f two new and possibly endemic species from the springs of Himmerland. Entomologicke Meddelelser 75: 384-404 - 1959. O n the evolution of various biological types w i t h i n the order Trichoptera. Proceedings of the Fifteenth International Congress o f Zoology, London, H.R. Hewer and N . D . Riley (eds.), pp. 1007-8 - 1981. On the evolution of the phallus and other male terminalia i n the Hydropsychidae w i t h a proposal for a new generic name. Proceedings o f the Third International Symposium on Trichoptera, Perugia, Italy, G.P. Moretti (ed.), pp. 275-80. The Hague: Junk N i m m o , A.P. 1965. A new species o f Psychoglypha Ross from western Canada, w i t h notes on several other species of Limnephilidae (Trichoptera). Canadian Journal o f Zoology 43(5): 781-87 - 1966. A list o f Trichoptera taken at Montreal and Chambly, Q u é b e c , w i t h descriptions of three new species. Canadian Entomologist 98(7): 688-93 - 1971. The adult Rhyacophilidae and Limnephilidae (Trichoptera) o f Alberta and eastern British Columbia and their post-glacial origin. Quaestiones Entomologicae 7: 3-234 - 1986. The adult Polycentropodidae of Canada and adjacent United States. Quaestiones Entomologicae 22: 143-252 439

Literature Cited -

1987. The adult Arctopsychidae and Hydropsychidae o f Canada and adjacent United States. Quaestiones Entomologicae 23: 1-189 - 1991. Tentative phylogeny of Desmona Denning, Monophylax n. gen., and species groups o f Psychoglypha Ross, based primarily on male characters (Trichoptera, L i m nephilidae, Limnephilinae, Chilostigmini). Proceedings o f the Sixth International Symposium on Trichoptera, Poland, 1989, C. Tomaszewski (ed.), pp. 343-48. Poznan: A d a m M i c k i e w i c z University Press

Novak, K . 1952. Tracheâln f soustava larev nasich Trichopter. Acta Societatis Zoologicae Bohemoslovenicae 16(3-4): 249-70 - 1960. E n t w i c k l u n g und Diapause der Kocherfliegenlarven Anabolia furcata Br. ( T r i chopt.). Casopis C e s k o s l o v e n s k é Spolecnosti Entomologice 57(3): 207-12 Novak, K . , and Sehnal, F. 1963. The development cycle of some species of the genus Limnephilus (Trichoptera). Casopis C e s k o s l o v e n s k é Spolecnosti Entomologice 60(1-2): 68-80 -

1965. Imaginaldiapause bei den i n periodischen Gewassern lebenden Trichopteren. Proceedings of the XII International Congress o f Entomology, London, 1964, p. 434

Noyes, A . A . 1914. The biology of the net-spinning Trichoptera of Cascadilla Creek. Annals o f the Entomological Society o f America 7(4): 251-72 Niiske, H . , and Wichard, W. 1971. Die Analpapillen der Kocherfliegenlarven. I . Feinstruktur und histochemischer Nachweis von Natrium und Chlorid bei Philopotamus montanus Donov. Cytobiologie 4(3): 480-86 - 1972. Die Analpapillen der Kocherfliegenlarven. i l . Feinstruktur des ionentransportierenden und respiratorischen Epithels bei Glossosomatiden. Cytobiologie 6(2): 243-49 Oemke, M.P. 1984. Diatom feeding preferences o f Glossosoma nigrior (Banks) larvae, stream grazers i n two southern M i c h i g a n streams. Proceedings of the Fourth International Symposium on Trichoptera, Clemson, S.C., 1983, J.C. Morse (ed.), pp. 285-90. The Hague: Junk Ogilvie, G.A., and Clifford, H.F. 1986. Life histories, production, and microdistribution of two caddisflies (Trichoptera) in a Rocky M o u n t a i n stream. Canadian Journal o f Z o o l ogy 64(12): 2706-16 Otto, C. 1976. Habitat relationships in the larvae o f three Trichoptera species. A r c h i v fur Hydrobiologie 77: 505-17 - 1983. Behavioural and physiological adaptations to a variable habitat i n two species of case-making caddis larvae using different food. Oikos 4 1 : 188-94 Parker, C.R., and Wiggins, G.B. 1985. The Nearctic caddisfly genus Hesperophylax choptera: Limnephilidae). Canadian Journal o f Zoology 61(10): 2443-72

(Tri-

1987. Revision o f the caddisfly genus Psilotreta (Trichoptera: Odontoceridae). Royal Ontario Museum, Life Sciences Contributions 144 Patterson, J.W., and Vannote, R . L . 1979. Life history and population dynamics of Heteroplectron americanum. Environmental Entomology 8(4): 665-69

-

Pearson, W . D . , and Kramer, R . H . 1972. Drift and production o f two aquatic insects i n a mountain stream. Ecological Monographs 42(3): 365-85 Percival, E., and Whitehead, H . 1929. A quantitative study of the fauna of some types o f stream-bed. Journal o f Ecology 17: 282-314 440

Literature Cited Petersen, R.C., Petersen, L . B . - M . , and Wallace, J.B. 1984. Influence of velocity and food availability on catchnet dimensions of Neureclipsis bimaculata (Trichoptera: Polycentropodidae). Holarctic Ecology 7: 380-89 Philipson, G . N . 1953a. A method o f rearing trichopterous larvae collected from swiftf l o w i n g waters. Proceedings of the Royal Entomological Society, London ( A ) , 28(1-3): 15-16 - 1953b. The larva and pupa of Wormaldia subnigra McLachlan (Trichoptera: Philopotamidae). Proceedings of the Royal Entomological Society, London ( A ) , 28(4-6): 57-62 - 1954. The effect o f water flow and oxygen concentration on six species o f caddis f l y (Trichoptera) larvae. Proceedings o f the Zoological Society, London, 124(3): 547-64 Resh, V . H . 1972. A technique for rearing caddisflies (Trichoptera). Canadian Entomologist 104(12): 1959-61 -

1976. The biology and immature stages of the caddisfly genus Ceraclea i n eastern North America (Trichoptera: Leptoceridae). Annals o f the Entomological Society o f America 69(6): 1039-61

-

1993. Recent trends in the use o f Trichoptera i n water quality monitoring. Proceedings of the Seventh International Symposium on Trichoptera, Sweden, 1992, C. Otto (ed.), pp. 2 8 7 - 9 1 . Leiden: Backhuys Publishers Resh, V . H . , Flynn, T.S., Lamberti, G.A., McElravy, E.P., Sorg, K . L . , and Wood, J.R. 1981. Responses of the sericostomatid caddisfly Gumaga nigricula ( M c L . ) to environmental disruption. Proceedings of the Third International Symposium on Trichoptera, Perugia, 1980, G.R Moretti (ed.), pp. 311-18. The Hague: Junk Resh, V.H., and Houp, R.E. 1986. Life history of the caddisfly Dibusa angata and its association w i t h the red alga Lemanea australis. Journal of the N o r t h American Benthological Society 5(1): 28-40 Resh, V . H . , Lamberti, G.A., and Wood, J.R. 1984. Biological studies of Helicopsyche borealis (Hagen) i n a coastal California stream. Proceedings o f the Fourth International Symposium on Trichoptera, Clemson, S.C., 1983, J.C. Morse (ed.), pp. 315-19. The Hague: Junk Resh, V . H . , Morse, J . C , and Wallace, I . D . 1976. The evolution of the sponge feeding habit in the caddisfly genus Ceraclea (Trichoptera: Leptoceridae). Annals of the Entomological Society o f America 69(5): 937-41 Resh, V.H., and Unzicker, J.D. 1975. Water quality monitoring and aquatic organisms: the importance o f species identification. Journal of the Water Pollution Control Federation 47(1): 9-19 Richardson, J.S. 1984. Prey selection and distribution of a predacious, net-spinning caddisfly, Neureclipsis bimaculata (Polycentropodidae). Canadian Journal o f Zoology 62(8): 1561-65 Richardson, J.S., and Clifford, H.F. 1983. Life history and microdistribution o f Neureclipsis bimaculata (Trichoptera: Polycentropodidae) in a lake outflow stream of Alberta, Canada. Canadian Journal o f Zoology 61(11): 2434-45 - 1986. Phenology and ecology o f some Trichoptera i n a low-gradient boreal stream. Journal o f the North American Benthological Society 5 (3): 191-99 Roemhild, G. 1982. The Trichoptera of Montana w i t h distributional and ecological notes. Northwest Science 56(1): 8-13 441

Literature Cited Ross, D.H., and Wallace, J.B. 1983. Longitudinal patterns of production, food consumption, and seston utilization by net-spinning caddisflies (Trichoptera) in a southern Appalachian stream (USA). Holarctic Ecology 6: 270-84 Ross, H.H. 1938. Descriptions of Nearctic caddis flies (Trichoptera) with special reference to the Illinois species. Bulletin of the Illinois Natural History Survey 21(4): 101-83 - 1944. The caddis flies, or Trichoptera, of Illinois. Bulletin of the Illinois Natural History Survey 23(1) - 1946. A review of the Nearctic Lepidostomatidae (Trichoptera). Annals of the Entomological Society of America 39(2): 265-91 - 1947. Descriptions and records of North American Trichoptera, with synoptic notes. Transactions of the American Entomological Society 73: 125-68 - 1948a. Notes and descriptions of Nearctic Hydroptilidae (Trichoptera). Journal of the Washington Academy of Sciences 38(6): 201-6 - 1948b. New species of sericostomatoid Trichoptera. Proceedings of the Entomological Society of Washington 50(6): 151-57 - 1949. Xiphocentronidae, a new family of Trichoptera. Entomological News 60(1): 1-7 - 1950. Synoptic notes on some Nearctic limnephilid caddisflies (Trichoptera, Limnephilidae). American Midland Naturalist 43(2): 410-29 - 1951a. The caddisfly genus Anagapetus (Trichoptera: Rhyacophilidae). Pan-Pacific Entomologist 27(3): 140-44 - 195 lb. Phylogeny and biogeography of the caddisflies of the genera Agapetus and Electragapetus (Trichoptera: Rhyacophilidae). Journal of the Washington Academy of Sciences 41(11): 347-56 - 1952. The caddisfly genus Molannodes in North America. Entomological News 63(4): 85-87 - 1956. Evolution and Classification of the Mountain Caddisflies. Urbana: University of Illinois Press - 1958. Affinities and origins of the northern and montane insects of Western North America. In Zoogeography, C L . Hubbs (ed.), pp. 231-52. Proceedings of two symposia: Joint Meeting of the American Institute of Biological Sciences and the American Association for the Advancement of Science at Stanford University, and the Annual Meeting of the AAAS, Indianapolis. Washington: AAAS Publication 51 - 1959. Trichoptera. In Fresh-water Biology, 2nd ιd., W.T. Edmondson (ed.), pp. 102449. New York: Wiley - 1964. Evolution of caddis worm cases and nets. American Zoologist 4: 209-20 - 1965. The evolutionary history of Phylocentropus (Trichoptera: Psychomyiidae). Journal of the Kansas Entomological Society 38(4): 398-400 - 1967. The evolution and past dispersal of the Trichoptera. Annual Review of Entomology 12: 169-206 - 1970. Hydropsychid genus A, Diplectrona (Trichoptera: Hydropsychidae). Journal of the Georgia Entomological Society 5(4): 229-31 - 1978. The present disposition of components of the Sericostomatidae s. lat. (Trichoptera). Proceedings of the Second International Symposium on Trichoptera, Reading, 1977, M.I. Crichton (ed.), pp. 1-6. The Hague: Junk Ross, H.H., and Gibbs, D.G. 1973. The subfamily relationships of the Dipseudopsinae 442

Literature Cited (Trichoptera, Polycentropodidae). Journal o f the Georgia Entomological Society 8(4): 312-16 Ross, H . H . , and K i n g , E.W. 1952. Biogeographic and taxonomic studies i n Atopsyche (Trichoptera, Rhyacophilidae). Annals of the Entomological Society of America 45(2): 177-204 Ross, H . H . , and Merkley, D.R. 1952. A n annotated key to the Nearctic males o f Limnephilus (Trichoptera, Limnephilidae). American M i d l a n d Naturalist 47(2): 435-55

Ross, H . H . , and Scott, D.C. 1974. A review o f the caddisfly genus Agarodes, w i t h descriptions of new species (Trichoptera: Sericostomatidae). Journal o f the Georgia Entomological Society 9(3): 147-55 Ross, H . H . , and Unzicker, J.D. 1965. The Micrasema rusticum group o f caddisflies (Brachycentridae, Trichoptera). Proceedings of the Biological Society o f Washington 78: 251-57 - 1977. The relationship of the genera o f American Hydropsychinae as indicated by phallic structures (Trichoptera: Hydropsychidae). Journal of the Georgia Entomological Society 12: 298-312 Ross, H . H . , and Wallace, J.B. 1974. The North American genera of the family Sericostomatidae (Trichoptera). Journal o f the Georgia Entomological Society 9(1): 42-48 Sattler, W. 1958. Beitrage zur Kenntnis von Lebensweise und Korperbau der Larve und Puppe v o n Hydropsyche Pict. (Trichoptera) mit besonderer Berucksichtigung des Netzbaues. Zeitschrift fur Morphologie und Ô k o l o g i e der Tiere 47(2): 115-92 1963a. D i e Larven- und Puppenbauten von Diplectrona felix M c L a c h . (Trichoptera). Zoologische Anzeiger 170(1/2): 53-55 - 1963b. Ù b e r den Korperbau, die Ô k o l o g i e und Ethologie der Larve und Puppe von M aero ne ma Pict. (Hydropsychidae), ein als Larve sich von ' M i k r o - D r i f t ' ernahrendes Trichopter aus dem Amazonasgebiet. A r c h i v fur Hydrobiologie 59(1): 26-60 - 1968. Weitere Mitteilungen iiber die Okethologie einer neotropischen MacronemaLarve (Hydropsychidae, Trichoptera). Amazoniana 1: 211-29 Sattler, W., and Kracht, A . 1963. Drift-Fang einer Trichopterenlarve unter Ausnutzung der Differenz von Gesamtdruck und statischem Druck des fliessenden Wassers. Naturwissenschaften 50: 362-63 Schefter, P.W., and Wiggins, G.B. 1986. A Systematic Study of the Nearctic Larvae o f the -

Hydropsyche

morosa Group (Trichoptera: Hydropsychidae). Royal Ontario Museum,

L i f e Sciences Miscellaneous Publications 1987. Setal characters i n larval diagnoses for some Nearctic species o f Cheumatopsyche (Trichoptera: Hydropsychidae). Proceedings o f the Fifth International Symposium on Trichoptera, Lyon, 1986, M . Bournaud, and H . Tachet (eds.), pp. 39-42. The Hague: Junk Schefter, P.W., Wiggins, G.B., and Unzicker, J.D. 1986. A proposal for assignment of Ceratopsyche as a subgenus of Hydropsyche, w i t h new synonyms and a new species (Trichoptera: Hydropsychidae). Journal of the North American Benthological Society 5(1): 67-84

-

Schmid, F. 1950a. Le genre Anabolia Steph. (Trichoptera, Limnophilidae). Revue Suisse d'Hydrologie 12(2): 300-39 - 1950b. Monographie du genre Grammotaulius Kolenati (Trichoptera Limnophilidae). Revue Suisse de Zoologie 57(7): 317-52 443

Literature Cited -

1950c. Le genre Halesochila Banks (Trichopt. Limnophilid.). Mitteilungen der Schweizerischen Entomologischen Gesellschaft 23(1): 55-60 1950d. L e genre Hydatophylax Wall. (Trichopt. Limnophilidae). Mitteilungen der Schweizerischen Entomologischen Gesellschaft 23(3): 265-96 1951. L e genre Ironoquia Bks. (Trichopt. L i m n o p h i l i d . ) . Mitteilungen der Schweizerischen Entomologischen Gesellschaft 24(3): 317-28 1952a. Les genres Glyphotaelius Steph. et Nemotaulius Bks. (Trichopt. Limnophil.). Bulletin de la Société Vaudoise des Sciences Naturelles 65(280): 213-44 1952b. L e groupe de Lenarchus Mart. (Trichopt. Limnophil.). Mitteilungen der Schweizerischen Entomologischen Gesellschaft 25(3): 157-210

-

1952c. Le groupe de Chilostigma. A r c h i v fiir Hydrobiologie 47(1): 75-163 1953. Contribution à l ' é t u d e de la sous-famille des Apataniinae (Trichoptera, L i m n o philidae). I . Tijdschrift voor Entomologie 96(1-2): 109-67

-

1954a. Contribution à l ' é t u d e de la sous-famille des Apataniinae (Trichoptera, L i m n o philidae). H. Tijdschrift voor Entomologie 97(1-2): 1-74

-

1954b. L e genre Asynarchus M c L . (Trichopt., Limnoph.). Mitteilungen der Schweizerischen Entomologischen Gesellschaft 27(2): 57-96 1955. Contribution à l ' é t u d e des Limnophilidae (Trichoptera). Mitteilungen der Schweizerischen Entomologischen Gesellschaft 28 1964a. Quelques Trichoptères asiatiques. Canadian Entomologist 96(6): 825-40 1964b. Some Nearctic species o f Grammotaulius K o l . (Trichoptera: Limnephilidae). Canadian Entomologist 96(6): 914-17 1965. Ergebnisse der zoologischen Forschungen von Dr. Z . Kaszab i n der M o n g o l e i . 63. Trichoptera. Reichenbachia 7(22): 201-3 1968a. La famille des Arctopsychides (Trichoptera). M é m o i r e s de la Société Entomologique du Q u é b e c 1 1968b. Quelques Trichoptères n é a r c t i q u e s nouveaux ou peu connus. Naturaliste Canadien 95(3): 673-98 1970. Le genre Rhyacophila et la famille des Rhyacophilidae (Trichoptera). Memoirs of the Entomological Society o f Canada 66 1979. On some new trends i n trichopterology. Bulletin o f the Entomological Society o f Canada 11:48-57

-

-

-

1980. Genera des T r i c h o p t è r e s du Canada et des États adjacents. Les Insectes et Arachnides du Canada. Partie 7. Agriculture Canada Publications 1692 1982. L a famille des Xiphocentronides (Trichoptera: Annulipalpia). Memoirs of the Entomological Society o f Canada 121 1983. Revision des Trichoptères Canadiens. III. Les Hyalopsychidae, Psychomyiidae, Goeridae, Brachycentridae, Sericostomatidae, Helicopsychidae, Beraeidae, Odontoceridae, Calamoceratidae et Molannidae. Memoirs of the Entomological Society o f Canada 125 1984. Essai d ' é v a l u a t i o n de la faune mondiale des Trichoptères. Proceedings o f the Fourth International Symposium on Trichoptera, Clemson (U.S.A.), 1983, J.C. Morse (ed.), p. 337 (Abstract). The Hague: Junk 1993. C o n s i d é r a t i o n s sur les H é l i c o p s y c h i d e s (Trichoptera, Integripalpia). Beaufortia 43(5): 65-100

444

Literature Cited Schmid, E , and B o t o § â n e a n u , L . 1966. Le genre Himalopsyche Banks (Trichoptera, Rhyacophilidae). Annales de la Société Entomologique du Q u é b e c 11(2): 123-76 Schmitz, M . , and Wichard, W. 1975. Ionenabsorption an Chloridepithelien von Kôcherfliegenlarven (Trichoptera). Entomologica Germanica 2(1): 30-34 -

1978. Der Ort der osmoregulatorischen Salzaufnahme bei Phryganeidae-Larven (Trichoptera). Mitteilungen der Schweizerischen Entomologischen Gesellschaft 5 1 : 99-102

Schmude, K . L . , and Hilsenhoff, W . L . 1986. Biology, ecology, larval taxonomy, and distribution o f Hydropsychidae (Trichoptera) i n Wisconsin. Great Lakes Entomologist 19: 123-45 Schuster, G.A., and Etnier, D . A . 1978. A manual for the identification o f the larvae of the caddisfly genera Hydropsyche Pictet and Symphitopsyche U l m e r i n eastern and central North America (Trichoptera: Hydropsychidae). United States Environmental Protection Agency Report 600/4-78-060 Schuster, G.A., and H a m i l t o n , S.W. 1984. The genus Phylocentropus in North America (Trichoptera: Polycentropodidae). Proceedings of the Fourth International Symposium on Trichoptera, Clemson (U.S.A.), 1983, J.C. Morse (ed.), pp. 347-62. The Hague: Junk Scott, K . M . F . 1961. Some new caddis flies (Trichoptera) from the Western Cape Province - III. Annals o f the South African Museum 46(2): 15-33 - 1983. O n the Hydropsychidae (Trichoptera) o f southern Africa w i t h keys to African genera o f imagoes, larvae and pupae and species lists. Annals of the Cape Provincial Museum (Natural History) 14(8): 299-^22 - 1985. Order Trichoptera. Chap. 24 in Insects of Southern Africa, C. H . Sholtz and E. H o l m (eds.). Durban: Butterworths Selgeby, J.H. 1974. Immature insects (Plecoptera, Trichoptera, and Ephemeroptera) collected from deep water i n western Lake Superior. Journal o f the Fisheries Research Board of Canada 31(1): 109-11 Sherberger, F.F., and Wallace, J.B. 1971. Larvae of the southeastern species o f Molanna. Journal o f the Kansas Entomological Society 44(2): 217-24 Sibley, C.K. 1926. Trichoptera. In A preliminary biological survey o f the Lloyd-Cornell Reservation. Bulletin o f the L l o y d Library 27: 102-8, 181-221 Silfvenius, A . J . 1905. B e i t r â g e zur Metamorphose der Trichopteren. Acta Societatis pro Fauna et Flora Fennica 27(6): 3-168 Siltala, A . J . 1907a. Trichopterologische Untersuchungen. N o . 2. Uber die postembryonale Entwicklung der Trichopteren-Larven. Zoologische Jahrbticher, suppl. 9(2): 309-626 - 1907b. Û b e r die Nahrung der Trichopteren. Acta Societatis pro Fauna et Flora Fennica, 9(5): 3-34 Smirnov, N . N . 1962. O n nutrition o f caddis worms Phryganea grandis L . Hydrobiologia 19: 252-61 Smith, D . H . 1979. The larval stage of Hydropsyche sychidae). Pan-Pacific Entomologist 55: 10-20

separata Banks (Trichoptera: Hydrop-

Smith, D . H . , and L e h m k u h l , D . M . 1980. The larvae o f four Hydropsyche species w i t h the checkerboard head pattern (Trichoptera: Hydropsychidae). Quaestiones Entomologicae 16: 625-34 Smith, M . H . 1984. A morphological distinction between the larvae o f

Cheumatopsyche 445

Literature Cited campyla and C. pettiti (Trichoptera: Hydropsychidae). Journal of the New York Entomological Society 92: 407-10 Smith, S.D. 1965. Distribution and biological records of Idaho caddisflies (Trichoptera). Entomological News 76(9): 242-45 - 1968a. The Arctopsychinae of Idaho (Trichoptera: Hydropsychidae). Pan-Pacific Entomologist 44(2): 102-12 - 1968b. The Rhyacophila of the Salmon River drainage of Idaho with special reference to larvae. Annals of the Entomological Society of America 61(3): 655-74 - 1969. Two new species of Idaho Trichoptera with distributional and taxonomic notes on other species. Journal of the Kansas Entomological Society 42(1): 46-53 - 1984a. Larvae of Nearctic Rhyacophila, Part I: acropedes group. Aquatic Insects 6(1): 37-40 - 1984b. Larvae of Nearctic Rhyacophila (Trichoptera: Rhyacophilidae) II: Rhyacophila lieftincki group. Journal of the Kansas Entomological Society 57(3): 540-42 Snodgrass, R.E. 1954. Insect metamorphosis. Smithsonian Miscellaneous Collections 122(9) Solem, J.O. 1970. Contributions to the knowledge of the larvae of the family Molannidae (Trichoptera). Norsk Entomologisk Tidsskrift 17(2): 97-102 - 1983. Larval and pupal descriptions of Asynarchus contumax McLachlan 1880 and A. lapponicus Zetterstedt 1840, with notes on bionomics in Central Norway (Trichoptera: Limnephilidae). Entomologica Scandinavica 14: 439-51 Stauffer, R.C., ed. 1975. Charles Darwin's Natural Selection, being the Second Part of His Big Species Book Written from 1856 to 1858. Cambridge, Eng.: Cambridge University Press Stehr, F.W. 1987. Techniques for collecting, rearing, preserving, and studying immature insects. Chap. 2 in Immature Insects, F.W. Stehr (ed.). Dubuque, Iowa: Kendall Hunt Sturm, H. 1960. Die terrestrischen Puppengehause von Xiphocentron sturmi Ross (Xiphocentronidae, Trichoptera). Zoologische Jahrbilcher, Systematik 87(4/5): 387-94 Sykora, J.L., Swegman, B.G., and Weaver, J.S. 1981. Occurrence of the genus Hydropsyche in the North American Great Lakes. Proceedings of the Third International Symposium on Trichoptera, Perugia, Italy, G.R Moretti (ed.), pp. 337-45. The Hague: Junk Thut, R.N. 1969. Feeding habits of larvae of seven Rhyacophila (Trichoptera: Rhyacophilidae) species with notes on other life-history features. Annals of the Entomological Society of America 62(4): 894-98 Tindall, A.R. 1960. The larval case of Triaenodes bicolor Curtis (Trichoptera: Leptoceridae). Proceedings of the Royal Entomological Society, London (A), 35(7-9): 93-96 - 1963. Some observations on the biology of caddis-fly larvae. Entomologist's Gazette, 14: 28-30 Tomaszewski, C. 1973. Studies on the adaptive evolution of the larvae of Trichoptera. Acta Zoologica Cracoviensia 18(13): 311-98 Ulmer, G. 1912. Die Trichopteren des baltischen Bernsteins. Beitrage zur Naturkunde Preussens, Konigsberg 10 - 1957. Kocherfliegen (Trichopteren) von den Sunda-Inseln. III. Archiv fiir Hydrobiologie, suppl. 23(2/4): 109-470 446

Literature Cited Vaillant, F. 1965. Les larves de Trichoptères hydroptilides mangeuses de substrat. Proceedings of the Twelfth International Congress of Entomology, London, 1964, Paul Freeman (ed.), p. 165 - 1984. The hydroptilid larvae living on dripping rocks. Proceedings of the Fourth International Symposium on Trichoptera, Clemson University, S.C., J.C. Morse (ed.), pp. 407-12. The Hague: Junk Van Dam, L. 1938. On the Utilization of Oxygen and Regulation of Breathing in Some Aquatic Animals. Groningen: Volharding Vineyard, R.N. 1982. An annotated checklist of the caddisflies (Trichoptera) of SE Alaska. Journal of the Entomological Society of British Columbia 79: 71-75 Vineyard, R.N., and Wiggins, G.B. 1987. Seven new species from North America in the caddisfly genus Neophylax (Trichoptera: Limnephilidae). Annals of the Entomological Society of America 80(1): 62-73 - 1988. Further revision of the caddisfly family Uenoidae (Trichoptera): evidence for inclusion of Neophylacinae and Thremmatidae. Systematic Entomology 13: 361-72 Vineyard, R.N., Wiggins, G.B., Frania, H.E., and Schefter, P.W. In press. Systematics of the caddisfly genus Neophylax (Trichoptera: Uenoidae). Royal Ontario Museum, Life Sciences Contributions Vorhies, C.T. 1905. Habits and anatomy of the larva of the caddis-fly, Platyphylax designatus Walker. Transactions of the Wisconsin Academy of Science, Arts and Letters 15: 108-23 - 1909. Studies on the Trichoptera of Wisconsin. Transactions of the Wisconsin Academy of Science, Arts and Letters 16: 647-738 Wagner, R., Aurich, M., Reder, E., and Veith, H.J. 1990. Defensive secretions from the larvae of Apatania fimbriata (Pictet) (Trichoptera: Limnephilidae). Chemoecology 1: 96-104 Wallace, I.D., Wallace, B., and Philipson, G.N. 1990. A key to the case-bearing caddis larvae of Britain and Ireland. Freshwater Biological Association, Scientific Publication no. 51 Wallace, I.D., and Wiggins, G.B. 1978. Observations on the larva and pupa of the caddisfly genus Hagenella (Trichoptera: Phryganeidae). Proceedings of the Second International Symposium on Trichoptera, Reading (England), 1977, M.I. Crichton (ed.), pp. 207-14. The Hague: Junk Wallace, J.B. 1975a. The larval retreat and food of Arctopsyche; with phylogenetic notes on feeding adaptations in Hydropsychidae larvae (Trichoptera). Annals of the Entomological Society of America 68(1): 167-73 - 1975b. Food partitioning in net-spinning Trichoptera larvae: Hydropsyche venularis, Cheumatopsyche etrona, and Macronema zebratum (Hydropsychidae). Annals of the Entomological Society of America 68(3): 463-72 Wallace, J.B., and Malas, D. 1976a. The fine structure of capture nets of larval Philopotamidae (Trichoptera), with special emphasis on Dolophilodes distinctus. Canadian Journal of Zoology 54(10): 1788-1802 - 1976b. The significance of the elongate, rectangular mesh found in capture nets of fine particle filter feeding Trichoptera larvae. Archiv fur Hydrobiologie 77(2): 205-12 Wallace, J.B., and Ross, H.H. 1971. Pseudogoerinae: a new subfamily of Odontoceridae (Trichoptera). Annals of the Entomological Society of America 64(4): 890-94 447

Literature Cited Wallace, J.B., and Sherberger, F.F. 1970. The immature stages o f Anisocentropus pyraloides (Trichoptera: Calamoceratidae). Journal o f the Georgia Entomological Society 5(4): 217-24 1974. The larval retreat and feeding net o f Macronema Carolina Banks (Trichoptera: Hydropsychidae). Hydrobiologia 4 5 ( 2 - 3 ) : 177-84 Wallace, J.B., Sherberger, S.R., and Sherberger, F.F. 1976. Use o f the diatom Terpsinoë musica Ehrenb. (Biddulphiales: Biddulphiaceae) as casemaking material by Nectop-

syche larvae (Trichoptera: Leptoceridae). American M i d l a n d Naturalist 95(1): 236-39 Wallace, J.B., Woodall, W.R., and Staats, A . A . 1976. The larval dwelling-tube, capture net and food o f Phylocentropus placidus (Trichoptera: Polycentropodidae). Annals o f the Entomological Society o f America 69(1): 149-54 Walton, I . 1653. The Compleat Angler. London: printed by T. Maxey for R. M a r r i o t Waltz, R.D., and McCafferty, W.R 1983. Austrotinodes Schmid (Trichoptera: Psychomyiidae), a first U.S. record from Texas. Proceedings o f the Entomological Society o f Washington 85(1): 181-82 Waters, T.F. 1962. Diurnal periodicity i n the drift o f stream invertebrates. Ecology 43(2): 316-20 -

1968. Diurnal periodicity i n the drift o f a day-active stream invertebrate. Ecology 49(1 ): 152-53 Weaver, J.S. 1985. A new species and new generic synonym of the Nearctic caddisfly genus Homoplectra (Trichoptera: Hydropsychidae). Entomological News 96(2): 71-77 - 1988. A synopsis o f the N o r t h American Lepidostomatidae (Trichoptera). Contributions o f the American Entomological Institute 24(2): 1-141 - 1993. Theliopsychinae, a new subfamily and Zephyropsyche, a new genus o f Lepidostomatidae. Proceedings o f the Seventh International Symposium on Trichoptera, Sweden, 1992, C. Otto (ed.), pp. 133-38. Leiden: Backhuys Publishers Weaver, J.S., Swegman, B . G . , and Sykora, J.L. 1979. The description o f immature forms o f Aphropsyche monticola Flint (Trichoptera: Hydropsychidae). Aquatic Insects 1(3): 143-48 Weaver, J.S., Wojtowicz, J.A., and Etnier, D . A . 1981. Larval and pupal descriptions o f Dolophilodes (Fumonta) major (Banks) (Trichoptera: Philopotamidae). Entomological News 92(3): 85-90 Wells, A . , and Cartwright, D . 1993. Females and immatures o f the Australian caddisfly Hyalopsyche disjuncta Neboiss (Trichoptera), and a new family placement. Transactions o f the Royal Society o f South Australia 117(2): 97-104 Wesenberg-Lund, C. 1911. Biologische Studien iiber netzspinnende, campodeoide T r i chopterenlarven. Internationale Revue der gesamten Hydrobiologie und Hydrographie, b i o l . suppl. ser. 3, 1: 1-64 White, J.S., and Brusven, M . A . 1994. Terrestrial behavior o f a larval caddisfly (Eocosmoecus schmidi) in a north Idaho stream. Abstract 353, Bulletin o f the N o r t h American Benthological Society, Spring 1994, 11(1): 191 W h i t e , T.R., and Fox, R.C. 1979. Chironomid (Diptera) larvae and hydroptilid (Trichoptera) pupae attached to a macromiid nymph (Anisoptera). Notulae Odonatologicae 1:76-77 448

,ITERATURE #ITED 7IBERG ,ARSEN 0 2EVISED KEY TO LARVAE OF "ERAEIDAE IN .7 %UROPE 4RICHOPTERA  %NTOMOLOGICA 3CANDINAVICA    7ICHARD 7 :UR -ORPHOGENESE DES RESPIRATORISCHEN %PITHELS DER 4RACHEENKIEMEN BEI ,ARVEN DER ,IMNEPHILINI +OL )NSECTA 4RICHOPTERA  :EITSCHRIFT FUR :ELLFORSCHUNG  

:UR MORPHOLOGISCHEN !NPASSUNG VON 4RACHEENKIEMEN BEI ,ARVEN DER ,IM NEPHILINI +OL )NSECTA 4RICHOPTERA  ))!DAPTATIONSVERSUCHE UNTER VERSCHIEDENEN  "EDINGUNGEN WAHREND DER LARVALEN %NTWICKLUNG /ECOLOGIA   

-ORPHOLOGISCHE +OMPONENTEN BEI DER/SMOREGULATION VON 4RICHOPTERENLARVEN 0ROCEEDINGS OF THE &IRST )NTERNATIONAL 3YMPOSIUM ON4RICHOPTERA ,UNZ AM 3EE !US TRIA  (-ALICKY ED PP   4HE (AGUE *UNK

4HEEVOLUTIONARY EFFECT OFOVERCOMING OSMOSIS IN4RICHOPTERA 0ROCEEDINGS OF THE 3IXTH )NTERNATIONAL 3YMPOSIUM ON4RICHOPTERA 0OLAND  # 4OMASZEWSKI ED PP   0OZNAN !DAM -ICKIEWICZ 5NIVERSITY 0RESS 7ICHARD 7 AND +OMNICK ( &INE STRUCTURE AND FUNCTION OF THEABDOMINAL CHLO RIDE EPITHELIA INCADDISFLY LARVAE :EITSCHRIFT FUR :ELLFORSCHUNG    7ICHARD 7 3CHMIDT (( AND7AGNER 2 4HE SEMIPERMEABILITY OF THE PUPAL COCOON OF 4RICHOPTERA 3PICIPALPIA  0ROCEEDINGS OF THE 3EVENTH )NTERNA TIONAL 3YMPOSIUM ON4RICHOPTERA 3WEDEN  #/TTO ED PP  ,EIDEN "ACKHUYS 0UBLISHERS 7ICHARD 7 AND 3CHMITZ - !NPASSUNGSMECHANISMEN DER OSMOREGULATORISCHEN )ONENABSORPTION BEI ,IMNEPHILIDAE ,ARVEN )NSECTA 4RICHOPTERA  RUND Abw sseR    7IGGINS '" 4HECADDISFLY GENUS IN .ORTH !MERICA 4RICHOPTERA  2OYAL /NTARIO -USEUM $IVISION OF :OOLOGY AND 0ALEONTOLOGY #ONTRIBUTION 

!REVISION OFTHE.ORTH !MERICAN CADDISFLY GENUS 4RICHOPTERA 0HRYG ANEIDAE  2OYAL /NTARIO -USEUM $IVISION OF:OOLOGY AND 0ALEONTOLOGY #ONTRIBUTION 

!METHOD OF REARING CADDISFLIES 4RICHOPTERA  #ANADIAN %NTOMOLOGIST    

A 4HE UNUSUAL PUPAL MANDIBLES INTHE CADDISFLY FAMILY 0HRYGANEIDAE 4RI CHOPTERA #ANADIAN %NTOMOLOGIST    

B! PRELIMINARY SYSTEMATIC STUDY OF THE.ORTH !MERICAN LARVAE OF THE CADDISFLY FAMILY 0HRYGANEIDAE 4RICHOPTERA  #ANADIAN *OURNAL OF :OOLOGY    

4HE REDISCOVERY OF ANUNUSUAL .ORTH !MERICAN PHRYGANEID WITH SOME ADDITIONAL RECORDS OFCADDISFLIES FROM .EWFOUNDLAND 4RICHOPTERA #ANADIAN %NTOMOLOGIST    

! NEW SUBFAMILY OF PHRYGANEID CADDISFLIES FROM WESTERN .ORTH !MERICA 4RI CHOPTERA 0HRYGANEIDAE  #ANADIAN *OURNAL OF :OOLOGY    

,ARVAE AND PUPAE OFTWO .ORTH !MERICAN LIMNEPHILID CADDISFLY GENERA 4RI CHOPTERA ,IMNEPHILIDAE  "ULLETIN OFTHE"ROOKLYN %NTOMOLOGICAL 3OCIETY    

!DDITIONS AND REVISIONS TOTHEGENERA OF.ORTH !MERICAN CADDISFLIES OF THE FAMILY "RACHYCENTRIDAE WITH SPECIAL REFERENCE TOTHE LARVAL STAGES 4RICHOPTERA  #ANADIAN %NTOMOLOGIST     



Literature Cited -

1966. The critical problem o f systematics i n stream ecology. In Symposium on Organism-Substrate Relationships i n Streams, K . W . Cummins, C.A. Tryon, and R . T Hartman (eds.), pp. 52-58. University o f Pittsburgh, Pymatuning Laboratory o f Ecology

-

1968. Contributions to the systematics o f the caddisfly family Molannidae in Asia (Trichoptera). Royal Ontario Museum, Life Sciences Contributions 72

-

1973a. A contribution to the biology o f caddisflies (Trichoptera) in temporary pools. Royal Ontario Museum, Life Sciences Contributions 88

-

1973b. New systematic data for the N o r t h American caddisfly genera Lepania, Goeracea and Goerita (Trichoptera: Limnephilidae). Royal Ontario Museum, Life Sciences Contributions 91

-

1973c. Contributions to the systematics o f the caddisfly family Limnephilidae (Trichoptera). I . Royal Ontario Museum, Life Sciences Contributions 94

-

1975. Contributions to the systematics o f the caddisfly family Limnephilidae (Trichoptera). I I . Canadian Entomologist 107(3): 325-36

-

1976. Contributions to the systematics of the caddis-fly family Limnephilidae (Trichoptera). I l l : The genus Goereilla. Proceedings o f the First International Symposium on Trichoptera, Lunz am See (Austria), 1974, H . M a l i c k y (ed.), pp. 7-19. The Hague: Junk

-

1977. Larvae o f the North American Caddisfly Genera (Trichoptera). 1st edition. U n i versity of Toronto Press

-

1981. Considerations on the relevance o f immature stages to the systematics o f T r i choptera. Proceedings o f the Third International Symposium on Trichoptera, Perugia, 1980, G.P Moretti (ed.), pp. 395-407. The Hague: Junk.

1982. Trichoptera. In Synopsis and Classification o f L i v i n g Organisms, edited by S.P Parker, pp. 599-612. New York: M c G r a w - H i l l - 1984a. Order Trichoptera. In A n Introduction to the Aquatic Insects o f North America (2nd edition revised), R.W. Merritt and K . W . Cummins (eds.), chapter 16, pp. 271-311. Dubuque, Iowa: Kendall Hunt -

1984b. Trichoptera - some concepts and questions. Keynote address in Proceedings o f the Fourth International Symposium on Trichoptera, Clemson University, S C . , J.C. Morse (ed.), pp. 1-12. The Hague: Junk - 1990. Systematics o f North American Trichoptera: present status and future prospect. In Systematics o f the North American Insects and Arachnids: Status and Needs. M . Kosztarab and C.W. Schaefer (eds.), pp. 203-10. Proceedings o f a Symposium, Annual Meeting, Entomological Society o f America, Louisville. Virginia Polytechnic Institute and State University, Virginia Agricultural Experiment Station Information Series no. 9 0 - 1 . -

-

1991. A metamorphotype o f Phanocelia canadensis (Banks) from 1100 years B.P. (Trichoptera: Limnephilidae). Proceedings o f the Sixth International Symposium on T r i choptera, Poland, 1989, C. Tomaszewski (ed.), pp. 453-57. Poznan: A d a m M i c k i e w i c z University Press

- I n press. The caddisfly family Phryganeidae (Trichoptera). University o f Toronto Press Wiggins, G.B., and Anderson, N . H . 1968. Contributions to the systematics o f the caddisfly genera Pseudostenophylax and Philocasca w i t h special reference to the immature stages (Trichoptera: Limnephilidae). Canadian Journal o f Zoology 46(1): 61-75 Wiggins, G.B., and Erman, N . A . 1987. Additions to the systematics and biology of 450

Literature Cited the caddisfly family Uenoidae (Trichoptera). Canadian Entomologist 119(10): 867-72 Wiggins, G.B., and Gall, W . K . 1993. The Asian caddisfly family Phryganopsychidae: phylogenetic novelty or relict? Proceedings of the Seventh International Symposium on Trichoptera, Sweden, 1992, C. Otto (ed.), 149-54. Leiden: Backhuys Publishers Wiggins, G.B., and Kuwayama, S. 1971. A new species of the caddisfly genus Oligotricha from northern Japan and Sakhalin, with a key to the adults of the genus (Trichoptera: Phryganeidae). K o n t y u 39(4): 340-46 Wiggins, G.B., and Larson, D.J. 1989. Systematics and biology o f a new Nearctic genus in the caddisfly family Phryganeidae (Trichoptera). Canadian Journal of Zoology 67(6): 1550-56 Wiggins, G.B., and Mackay, R.J. 1978. Some relationships between systematics and trophic ecology i n Nearctic aquatic insects, w i t h special reference to Trichoptera. Ecology 59(6): 1211-20 Wiggins, G.B., Mackay, R.J., and Smith, I . M . 1980. Evolutionary and ecological strategies o f animals i n annual temporary pools. A r c h i v fur Hydrobiologie supplement 58 (1/2): 97-206 Wiggins, G.B.,and Parker, C.R. In press. Caddisflies (Trichoptera) of the Yukon, w i t h analysis of the Holarctic and Beringian species o f North America. In Insects o f the Yukon, G.G.E. Scudder and J. A . Downes (eds.). Biological Survey of Canada (Terrestrial Arthropods), Entomological Society o f Canada, Ottawa Wiggins, G.B., and Richardson, J.S. 1982. Revision and synopsis of the caddisfly genus Dicosmoecus (Trichoptera: Limnephilidae). Aquatic Insects 4(4): 181-217

1987. Revision o f the Onocosmoecus unicolor group (Trichoptera: Limnephilidae: Dicosmoecinae). Psyche 93(3-4)(1986): 187-216 - 1989. Biosystematics o f Eocosmoecus, a new Nearctic caddisfly genus (Trichoptera: Limnephilidae, Dicosmoecinae). Journal of the North American Benthological Society 8(4): 355-69 -

Wiggins, G.B, Tani, K . , and Tanida, K . 1985. Eobrachycentras, a genus new to Japan, w i t h a review o f Japanese Brachycentridae (Trichoptera). Kontyu 53(1): 59-74 Wiggins, G.B., Weaver, J.S., and Unzicker, J.D. 1985. Revision of the caddisfly family Uenoidae (Trichoptera). Canadian Entomologist 117(6): 763-800 Wiggins, G.B., and Wichard, W. 1989. Phylogeny of pupation i n Trichoptera, w i t h proposals on the origin and higher classification of the order. Journal of the North American Benthological Society 8(3): 260-76 Wiggins, G.B., and Winchester, N . N . 1984. A remarkable new caddisfly genus from northwestern N o r t h America (Trichoptera, Limnephilidae, Limnephilinae). Canadian Journal o f Zoology 62(9): 1853-58 Wiggins, G.B., and Wisseman, R.W. 1990. Revision o f the North American caddisfly genus Desmona (Trichoptera: Limnephilidae). Annals o f the Entomological Society of America 82(2): 155-61 -

1992. New North American species i n the genera Neothremma and Farula, with hypotheses on phylogeny and biogeography (Trichoptera: Uenoidae). Canadian Entomologist 124(6): 1063-74

Williams, D . D . , and Hynes, H . B . N . 1974. The occurrence o f benthos deep i n the substratum o f a stream. Freshwater Biology 4(3): 233-56 451

Literature Cited W i l l i a m s , D . D . , and Penak, B . L . 1980. Some aspects o f case building i n Phryganea cinerea Walker (Trichoptera: Phryganeidae). A n i m a l Behaviour 28: 103-10 Williams, D . D . , Read, A.T., and Moore, K . A . 1983. The biology and zoogeography of Helicopsyche borealis (Trichoptera: Helicopsychidae): a Nearctic representative of a tropical genus. Canadian Journal o f Zoology 61(10): 2288-99 W i l l i a m s , D . D . , and W i l l i a m s , N . E . 1975. A contribution to the biology of Ironoquia -

punctatissima (Trichoptera: Limnephilidae). Canadian Entomologist 107(8): 829-32 1981. Some aspects of the life history and feeding ecology of Dolophilodes distinctus (Walker) in two Ontario streams. Proceedings o f the Third International Symposium on Trichoptera, Perugia, 1980, G.P. M o r e t t i (ed.), pp. 431-40. The Hague: Junk

W i l l i a m s , D . , Tavares, A.F., and Bryant, E. 1987. Respiratory device or camouflage? - A case for the caddisfly. Oikos 50: 42-52 W i l l i a m s , N . E . , and Hynes, H . B . N . 1973. Microdistribution and feeding o f the net-spinning caddisflies (Trichoptera) of a Canadian stream. Oikos 24: 73-84 W i l l i a m s , N . E . , and Wiggins, G.B. 1981. A proposed setal nomenclature and homology for Trichoptera. Proceedings o f the T h i r d International Symposium on Trichoptera, Perugia, 1980, G.P. Moretti (ed.), 421-29. The Hague: Junk Winchester, N . N . , Wiggins, G.B., and Ring, R. 1993. The immature stages and biology of the unusual North American caddisfly Sphagnophylax meiops, w i t h consideration of the phyletic relationships of the genus (Trichoptera: Limnephilidae). Canadian Journal o f Zoology 71(6): 1212-20 Winterbourn, M . J . 1971a. The life histories and trophic relationships of the Trichoptera of M a r i o n Lake, British Columbia. Canadian Journal o f Zoology 49(5): 623-35 -

1971b. A n ecological study o f Banksiola crotchi Banks (Trichoptera, Phryganeidae) i n M a r i o n Lake, British Columbia. Canadian Journal o f Zoology 49(5): 637-45

Wisseman, R.W., and Anderson, N . H . 1987. The life history of Cryptochia pilosa (Trichoptera: Limnephilidae) in an Oregon coast range watershed. Proceedings of the Fifth International Symposium on Trichoptera, Lyon, 1986, M . Bournaud and H . Tachet (eds.), pp. 243-46. Dordrecht: Junk -

1991. The life history o f Onocosmoecus unicolor (Limnephilidae: Dicosmoecinae) in an Oregon coast watershed. Proceedings o f the Sixth International Symposium on T r i choptera, Poland, C. Tomaszewski (ed.), pp. 159-63. Poznan: Adam M i c k i e w i c z U n i versity Press

Wood, J.R., and Resh, V . H . 1991. Morphological and ecological variation in stream and spring populations of Gumaga nigricula (McLachlan) in the California ( U S A ) coast ranges. Proceedings of the Sixth International Symposium on Trichoptera, Poland, 1989, C. Tomaszewski (ed.), pp. 15-20. Poznan: Adam M i c k i e w i c z University Press Yamamoto, T., and Ross, H . H . 1966. A phylogenetic outline of the caddisfly genus Mystacides (Trichoptera: Leptoceridae). Canadian Entomologist 98(6): 627-32 Yamamoto, T., and Wiggins, G.B. 1964. A comparative study o f the North American species i n the caddisfly genus Mystacides (Trichoptera: Leptoceridae). Canadian Journal of Zoology 42(6): 1105-26 Yang, L . , and Morse, J.C. 1993. Phylogenetic outline of Triaenodini (Trichoptera: Leptoceridae). Proceedings o f the Seventh International Symposium on Trichoptera, Sweden, 1992, C. Otto (ed.), pp. 161-67. Leiden: Backhuys Publishers 452

Taxonomic Index

Taxa of subgeneric to subordinal status in this book are listed here. Valid genera in the checklist of Nearctic Trichoptera (Ross 1944: 291-303) are included. Entries after each name refer to pages on which there is some information concerning that taxon. Page entries are in numerical order; plate references are found at the end of the page references. Abaria 185 Adicrophleps 11, 207, 208, 14.1 Agapetinae 9, 51 Agapetus 9, 23, 52, 54, 1.1 Agarodes 13, 406, 25.1 Agraylea 8, 73,76, 78,3.1 Agrypnia 10, 376, 378, 23.1 Alisotrichia 8, 74, 75, 80, 3.2 Allocosmoecus 11, 269, 276, 278, 300, 20.1 Allomyia 12, 191, 192, 12.1 Amiocentrus 11, 207, 210, 14.2 Amphicosmoecus 11, 269, 277, 280, 20.2 Anabolia 11, 270, 275, 282, 20.3 Anagapetus 9, 52, 56, 1.2 Anisocentropus 13, 219, 220, 15.1 Annulipalpia 9, 15, 16, 18, 19, 21, 117 Anseriglossa 60 Apatania 12, 191, 194, 12.2

Arctopsyche 10, 127, 128, 130, 144, 7.1 Arctopsychidae 127 Arctopsychinae 10, 127 Astenophylax 322

Apataniidae 12, 16, 20, 34, 46, 189, 190, 269 Apataniinae 190 Aphropsyche 136

Caborius 324

Archithremma 234 Archithremmatinae 226 Arctopora 11, 270, 275, 284, 20.4

Asynarchus 11, 270, 274, 275, 286, 316, 328, 20.5 Athripsodes 250, 252 Athripsodini 250 Atopsyche 8, 68, 2.1 Austrotinodes 10, 124,6.1 Banksiola 10, 376, 380, 390, 23.2 Beothukus 10, 376, 382, 384, 23.3 Beraea 13,204, 13.1 Beraeidae 13, 16, 20, 46, 189, 203 Brachycentridae 11, 16, 20, 45, 189, 206 Brachycentrus 11, 207, 212, 14.3

Calamoceratidae 13, 16, 20, 45, 189, 218 Ceraclea 13, 24, 250, 251, 252, 19.1 Ceratopsyche 138 Cernotina 10, 161, 162, 170, 9.1 Chaetopterygini 270

453

454

Taxonomic Index

Cheumatopsyche 10, 128, 129, 132, 7.2 Chilostigma 11, 270, 273, 288, 20.6 Chilostigmini 270 Chilostigmodes 11, 270, 271 Chimarra 9, 151, 152, 8.1 Chimarrinae 9, 151 Chyranda 11, 270, 272, 290, 294, 20.7 Clistoronia 11, 270, 274, 292, 20.8 Clostoeca 11, 270, 273, 294, 20.9 Cnodocentron 10, 185 Cryptochia 11, 269, 271, 296, 20.10 Culoptila9, 53, 58, 1.3 Curgia 152 Cyrnellus 10, 161, 164, 9.2 Cyrnus 168 Desmona 11, 270, 272, 298, 334, 20.11 Dibusa 8, 75, 82, 106, 3.3 Dicosmoecinae 11, 269 Dicosmoecus 11, 23, 269, 276, 300, 20.12 Diplectrona 10, 127, 129, 134, 7.3 Diplectroninae 10, 127 Dipseudopsidae 10, 15, 16, 20, 45, 117, 118, 160 Dipseudopsis 118 Doloclanes 156 Dolophilodes 9, 151, 154, 156, 8.2 Dolophilus 156 Drusinae 269 Drusinus 342 Ecclisocosmoecus 11, 269, 273, 302, 20.13 Ecclisomyia 11, 269, 271, 304, 20.14 Ecclisopteryginae 269 Ecnomidae 10, 16, 43, 117, 123 Ecnomina 123 Ecnomus 123

Fattigia 13, 408, 25.2 Frenesia 12, 270, 275, 308, 20.16 Fumonta 154 Ganonema 222 Glossosoma 9, 24, 52, 60, 1.4 Glossosomatidae 9, 16, 20, 44, 49, 50 Glossosomatinae 9, 51 Glyphopsyche 12, 270, 275, 310, 20.17 Glyphotaelius 330 Goera 12, 227, 228, 16.1 Goeracea 12, 227, 230, 16.2 Goereilla 11, 399, 400, 24.1 Goeridae 12, 16, 20, 34, 45, 189, 226 Goerinae 12, 226 Goerita 12, 227, 232, 16.3 Goerodes 242 Grammotaulius 12, 270, 276, 312, 20.18 Grensia 12, 270, 273, 314, 20.19 Gumaga 13, 410, 25.3 Hagenella 10, 376, 386, 23.5 Halesochila 12, 270, 274, 286, 316, 20.20 Helicopsyche 13, 238, 17.1 Helicopsychidae 13, 16, 20, 43, 189, 237 Hesperophylax 12, 270, 277, 318, 20.21 Heteroplectron 13, 218, 222, 15.2 Himalopsyche 8, 110, 112, 4.1 Holocentropus 160 Homophylax 12, 270, 272, 320, 20.22 Homoplectra 10, 127, 129, 136,7.4 Hyalopsyche 119 Hyalopsychidae 119, 160 Hydatophylax 12, 270, 272, 322, 348, 20.23 Hydrobiosidae 8, 16, 44, 67 Hydropsyche 10, 24, 126, 128, 129, 132, 138, 7.5

Eobrachycentrus 11, 207, 214, 14.4 Eocosmoecus 11, 269, 277, 306, 332, 20.15 Eodipseudopsis 118 Eomystra 60 Eubasilissa 388

Hydropsychidae 10, 16, 20,43, 117, 126 Hydropsychinae 10, 128 Hydropsychoidea 8, 9, 117 Hydroptila 9, 73, 76, 84, 96, 104, 3.4 Hydroptilidae 8, 15, 16, 18, 20, 34, 43, 49, 71, 126

Fabria 10, 377, 382, 384, 23.4

Hydroptilinae 8, 73 Hydroptilini 73

Farula 12, 413, 415, 416, 420, 26.1

454

Taxonomic Index Imania 192 Integripalpia 10, 15, 16, 17, 19, 21, 189, 206

455

Molannidae 13, 15, 16, 20, 34, 46, 189, 352

Ironoquia 11, 23, 269, 277, 324, 20.24

Molannodes 13, 353, 356, 21.2

Ithytrichia 9, 72, 74, 77, 86, 3.5

Monophylax 298

Lenarchulus 284

Moselyana 12, 191, 198, 12.4

Lenarchus 12, 270, 277, 326, 20.25

Mystacides 13, 249, 250, 251, 256, 19.3

Lepania 12, 227, 234, 16.4

Mystacidini 250

Lepaniinae 12, 226

Mystrophora 60

Mormomyia 241

Lepidostoma 11, 241, 243, 244, 246, 18.1 Lepidostomatidae 11, 15, 16, 20, 45, 189, 241

Namamyia 13, 360, 361, 364, 22.2

Lepidostomatinae 11, 242

Nectopsyche 13, 249, 250, 251, 258, 19.4

Leptecho 237

Nectopsychini 250

Leptocella 250, 258

Nemotaulius 12, 270, 274, 330, 20.27

Leptoceridae 13, 15, 16, 20, 44, 189, 249

Neodinarthrum 241

Leptocerinae 13, 250

Neophylacinae 269, 414

Leptocerini 250

Neophylax 12, 23, 24, 228, 413, 414, 415,

Leptoceroidea 13, 189 Leptocerus 13, 249, 250, 254, 19.2

418, 26.2 Neothremma 12, 413, 414, 416, 420, 26.3

Leptonema 10, 128, 129, 140, 7.6

Neotrichia 9, 73, 76, 90, 94, 3.9

Leptophylax 12, 270, 271

Neotrichiini 73

Leucotrichia 9, 72, 73, 75, 80, 88, 108, 3.6

Nerophilus 13, 361, 366, 22.3

Leucotrichiini 73, 75

Neureclipsis 10, 160, 166,9.3

Limnephilidae 11, 15, 16, 20, 22, 34, 46, 189,

Neuronia 394

268

Nosopus 241

Limnephilinae 11, 270

Notiomyia 224

Limnephilini 34, 270

Nyctiophylax 10, 160, 168, 9.4

Limnephiloidea 8, 11, 189, 269 Limnephilus 12, 270, 274, 276, 286, 328, 336, 346, 20.26

Ochrotrichia 9, 72, 74, 76, 84, 92, 96, 3.10 Ochrotrichiini 74

Limnoecetis 118

Odontoceridae 13, 16, 20,47, 189, 359

Lype 9, 175, 176, 10.1

Odontocerinae 13, 360

Macronema 142

Oecetini 250

Macronematinae 10, 128

Oecetis 13, 250, 251, 260, 19.5

Macrostemum 10, 128, 129, 142, 7.7

Oligophlebodes 12, 414, 415, 422, 26.4

Madeophylax 196

Oligoplectrum 212

Manophylax 12, 191, 196, 12.3

Oligostomis 11, 376, 388, 23.6

Odontocerum 359

Marilia 13, 361, 362, 22.1

Oligotricha 11, 376, 380, 390, 23.7

Matrioptila 9, 53, 62, 1.5

Onocosmoecus 11, 269, 277, 280, 306, 332,

Mayatrichia 9, 73, 76, 90, 94, 3.7

20.28

Melanotrichia 185

Oropsyche 10, 127, 128, 136

Metrichia 9, 74, 75, 92, 3.8

Orthotrichia 9, 74, 77, 98, 3.11

Micrasema 11, 207, 216, 14.5

Orthotrichiini 74

Molanna 1 3 , 3 5 3 , 3 5 4 , 2 1 . 1

Oxyethira 9, 72, 73, 76, 100, 3.12

455

456

Taxonomic Index

Paduniella9, 175, 178, 180, 10.2 Paduniellinae 9, 174 Palaeagapetus 8, 73, 75, 102, 3.13 Parachiona 296 Paranyctiophylax 168 Parapsyche 10, 127, 128, 130, 144, 7.8 Parecnomina 123 Parthina 13, 361, 368, 22.4 Paucicalcaria 9, 73, 76, 104, 3.14 Pedomoecus 12, 191,200, 12.5 Phanocelia 12, 270, 271, 334, 20.29 Philarctus 12, 270, 275, 286, 328, 336, 20.30 Philocasca 12, 270, 273, 306, 338, 20.31 Philopotamidae 9, 16, 20, 44, 117, 150 Philopotaminae 9, 151 Philopotamoidea 9, 117 Phryganea 10, 376, 392, 23.8 Phryganeidae 10, 15, 16, 20, 23, 44, 189, 374 Phryganeinae 10, 375 Phryganeoidea 10, 189 Phylloicus 13,219, 224, 15.3 Phylocentropus 10, 120, 5.1 Platycentropus 12, 270, 276, 340, 20.32 Platyphylax 318 Plectrocnemia 160 Plectropsyche 128 Polycentropodidae 10, 15, 16, 20, 45, 117, 159, 174 Polycentropodinae 10, 159, 160 Polycentropus 10, 161, 162, 164, 170, 9.5 Polyplectropus 10, 160, 172, 9.6 Potamyia 10, 128, 129, 146, 7.9 Protodipseudopsis 118, 120 Protoptila9, 53,64, 1.6 Protoptilinae 9, 52 Pseudogoera 13, 360, 361, 370, 22.5 Pseudogoerinae 13, 360 Pseudoneureclipsinae 160 Pseudostenophylacinae 11, 270 Pseudostenophylax 11, 270, 273, 342, 20.33 Psilotreta 13, 359, 360, 361, 372, 22.6 Psychoglypha 12, 270, 272, 304, 344, 20.34 Psychomyia9, 175, 178, 180, 10.3 Psychomyiidae 9, 16, 20, 45, 117, 174 Psychomyiinae 9, 174

456

Psychoronia 12, 270, 277, 346, 20.35 Ptilocolepinae 8, 73, 102 Ptilocolepus 73, 102 Ptilostomis 11,377,394, 23.9 Pycnopsyche 12, 23, 24, 270, 272, 322, 348, 20.36 Radema 194 Rhyacophila 8, 111, 114, 194, 4.2 Rhyacophilidae 8, 16, 20, 44, 49, 110 Rhyacophiloidea 8 Rhyacophylax 148 Rioptila 80 Ripaeglossa 60 Rossiana 11, 399, 402, 24.2 Rossianidae 11, 16, 46, 189, 269, 399 Sericostoma 404 Sericostomatidae 13, 16, 20, 47, 189, 404 Sericostomatoidea 13, 189 Sericostriata 12, 413, 414, 424, 26.5 Setodes 13, 250, 254, 262, 19.6 Setodini 250 Silo 228 Smicridea 10, 128, 129, 148, 7.10 Smicrideini 148 Sortosa 154 Sphagnophylax 12, 270, 276, 350, 20.37 Spicipalpia 8, 14, 16, 19,49 Stactobiella 9, 74, 75, 106, 3.15 Stactobiini 74 Stenophylacini 270 Stenophylax 338 Stenopsychidae 117 Symphitopsyche 138 Tascobia 106 Theliopsyche 11, 241, 242, 243, 246, 18.2 Theliopsychinae 11, 242 Thremma 414 Thremmatinae 12, 414 Tinodes 9, 174, 175, 182, 10.4 Trentonius 154 Triaenodes 13, 250, 251, 264, 266, 19.7 Triaenodini 250

T a x o n o m i c Index

Triplectidinae 250

457

Xiphocentron 9, 186, 11.1 Xiphocentronidae 9, 16, 45, 117, 185

Uenoa 413 Uenoidae 12, 16, 34, 46, 189, 269, 413 Uenoinae 12, 413

Ylodes 13, 250, 251, 264, 266, 19.8 Yphria 10, 375, 396, 23.10 Yphriinae 10, 375

Wormaldia 9, 151, 154, 156, 8.3

Zumatrichia 9, 72, 73, 75, 108, 3.16

457