The Other Lepidoptera: Moth Conservation in Australia: Moth Conservation in Australia 3031321022, 9783031321023

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Tim R. New

The Other Lepidoptera: Moth Conservation in Australia

The Other Lepidoptera: Moth Conservation in Australia

Tim R. New

The Other Lepidoptera: Moth Conservation in Australia

Tim R. New Department of Environment and Genetics La Trobe University Bundoora, VIC, Australia

ISBN 978-3-031-32103-0 ISBN 978-3-031-32102-3 https://doi.org/10.1007/978-3-031-32103-0

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© The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2023 This work is subject to copyright. All rights are solely and exclusively licensed by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors, and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, expressed or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. This Springer imprint is published by the registered company Springer Nature Switzerland AG The registered company address is: Gewerbestrasse 11, 6330 Cham, Switzerland

Preface

Lepidoptera have a unique and predominant role in insect natural history and conservation, in large part as the heritage of more than two centuries of collector and hobbyist interests founded in western Europe, and with those interests spreading progressively throughout the world. Modern insect conservation has its foundations in concerns for butterflies, for long appreciated as symbols of well-being in the natural world, but also of sufficient interest to naturalists that declines and losses have caused wide concerns and calls for conservation of individual species, wider assemblages, and the many distinctive but vulnerable terrestrial ecosystems that butterflies frequent and on which they depend. However, the butterflies, with around 18–20,000 described species, are but a small component of the Lepidoptera. The remaining 150,000 or so described species, moths, are far less heeded—but are assuredly no less important in their varied and central ecological roles over much of the world. Despite their diversity and potential vulnerabilities, moths—other than a few families with large spectacular species and the relatively low numbers of species with conspicuous day-active adults (some of which have informally been accorded the status of ‘honorary butterflies’)—have until recently received far less conservation attention, notwithstanding the severe and widespread declines in richness and abundance that have been reported or implied strongly over much of the world. Conservation of moths, as the often disregarded ‘Other Lepidoptera’, faces considerable problems flowing from a combination of their taxonomic and ecological diversity and low public perception of their worth. In practice, the popular images of many moths are tarnished by the reality that some moths are among the most serious pests of agriculture and demand strenuous efforts to suppress them. As for Orthoptera, in which closely related species of grasshoppers can be innocuous, perhaps threatened by human activities, or notoriously damaging crop pests (as ‘locusts’), the wider public image of many innocuous moths suffers from such unwarranted or extrapolated association. It can be very difficult, for instance, for even experienced entomologists to distinguish reliably between closely related and similar species of moths that are major pests of food crops or that are severely threatened by loss of their natural habitats. In short, v

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whereas many people like butterflies, equally many of those same people do not like moths, and this contrasting perception continues to hamper progress in much-needed conservation assessment and activity: changing public awareness and perceptions of moths is an important component of promoting their conservation, and of extending the conservation expertise and experience developed for butterflies to their closest insect analogues. The major lesson is that relatively few moth taxa are ‘pests’ and the vast majority of species intrude little on human welfare. As one of the largest insect orders, found in all vegetated areas of the world, Lepidoptera participate in a vast range of ecological interactions, predominantly in terrestrial environments. They are ecologically diverse, with species ranging from extreme specialists with very constrained resources and small distributions to widely distributed generalists. As, perhaps, the most thoroughly documented and popular insect group, the values of butterflies in developing sound insect conservation principles and practice are well known. Despite their ubiquity and greater diversity, moths lag considerably. Their potential to contribute to insect conservation and, indeed, their increasing needs as their habitats are lost and changed by human activities are gradually becoming acknowledged, but far greater involvement is warranted. The conservation foundations developed for butterflies demonstrate the principles and approaches that can be extended confidently to their closest—and often co-occurring—relatives. Indeed, moths are increasingly complementing butterflies in insect conservation as their ecological variety becomes better appreciated and their responses to environmental changes better understood. This book is a survey of information on moths in conservation—both needs and practice, and the wider lessons their study provides. An earlier compendium (introduced by New 2004) assembled some of the information then available on moths in conservation. Much has happened since then, and this gratifying and significant increased attention is the major focus here. Many aspects of insect diversity and conservation have been illuminated by studies on moths. Following the precedent of the far more numerous butterfly studies, individual ‘flagship species’ have expanded public and political appreciation of needs, and the wider diversity of moths contributed to a greater understanding of vulnerabilities and conservation need. My main focus is on moths in Australia, where the lessons learned elsewhere have much to contribute in many contexts of insect conservation, but where basic knowledge of the moth fauna remains relatively incomplete, even as concerns for its fate increase. The Australian moth fauna and its varied habitats continue to be threatened by human activities, and massive erosion of key vegetation systems has already removed and degraded many key restricted habitats. The situation summarised by Austin et al. (2004) as ‘Australian Lepidoptera are increasingly threatened with local or complete extinction from land-use changes especially in the south and east, but conservation planning to secure their future is only just beginning’ remains highly relevant nearly two decades later. Most of our moth species occur nowhere else, and their loss in Australia thus represents global extinction of unique evolutionary heritage—and of taxa no less significant than our far more heeded native mammals and birds, many of them also of serious conservation concern. Many of our moth species are believed to be both rare and restricted in range, mostly as putative

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narrow-range endemics, and many have not been seen since they were described, perhaps a century or more ago. Many, perhaps most, people charged with conserving insects in Australia are not primarily entomologists. This book is predominantly for those non-specialists, with the purpose of providing the broader background from which they can build in embracing moths as an important focus in this endeavour. I have drawn on published and more informal literature available up to late 2022, to select and summarise relevant background and examples from across the world in which moth conservation has garnered greater attention, to demonstrate the breadth of needs and how these may be pursued and, perhaps, emulated. Fuller information on moth biology and ecology is available from numerous other books, among which those by Young (1997) and Majerus (2002) have become classics and two more recent accounts (Lee and Zilli 2019; Sourakov and Chadd 2022) are both informative and thoughtprovoking. This book comprises two main sections. Chapters 1–5 are a general introduction to moth diversity, ecology, and conservation, as background to the primarily Australian focus to follow, and illustrating how studies elsewhere are indeed highly relevant to guiding and developing moth conservation and interests in Australia. Of these, the first chapter discusses moth evolution and diversity and Chap. 2 introduces some relevant aspects of their ecology. I should emphasise that these are not intended to fully cover the myriad complex themes and debates that continually arise but are focused on founding the conservation perspectives that become more prevalent from Chap. 3 onwards, through appraisals of moth declines and the factors involved in conservation concern (Chaps. 4 and 5). Chapters 6–10 focus more specifically on Australian moths and expand and examine this increasing awareness and the needs for greater attention to moths as a key future focus for insect conservation, examining moth diversity, variety, and their habitats (Chap. 6), the major national and more parochial threats that must be considered and countered (Chap. 7), advances through selected species conservation interests (Chap. 8), and the development and future of wider conservation focus, priorities, and practice (Chaps. 9 and 10). Chapters are referenced independently, and the publisher’s requirement for each chapter to be read independently has necessitated some examples and topics being revisited in different contexts across the book; page crossreferences throughout the text facilitate integration of these. Melbourne, Australia

Tim R. New

References Austin AD, Yeates DK, Cassis G, Fletcher MJ, La Salle J et al (2004) Insects ‘down under’ – diversity, endemism and evolution of the Australian insect fauna: examples from select orders. Aust J Entomol 43:216–234 Lees DC, Zilli A (2019) Moths: their biology, diversity and evolution. The Natural History Museum, London

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Majerus M (2002) Moths. Harper-Collins, London New TR (2004) Moths (Insecta: Lepidoptera) and conservation: background and perspective. J Insect Conserv 8:79–94 Sourakov A, Chadd RW (2022) The lives of moths. A natural history of our planet’s moth life. Princeton University Press, Princeton Young MR (1997) The natural history of moths. Poyser, London

Acknowledgements

The following publishers and organisations are thanked for granting permission to reproduce illustrations or tables from publications to which they hold copyright; some others are used under Creative Commons licences, noted individually in headings. Thanks are extended to Cambridge University Press, CSIRO Publishing (Melbourne), Elsevier, John Wiley and Sons, the Royal Society (London), and Springer Nature. Most figures have been redrawn to ensure standardisation of lettering. Every effort has been made to obtain such permissions, and the publishers would welcome advice of any inadvertent omissions that should be included in any future reprint or edition of this work. Advice on particular taxa of moths from New Zealand from Dr Robert Hoare and from Australia by Dr Simon Grove and Dr Don Sands is gratefully acknowledged and noted in context. Dr Peter Caley generously advised on aspects of his Bogong moth assessments. Dr Lars Koerner, as editor, has provided wise encouragement and advice, responded to my queries rapidly and effectively, and helped greatly with gaining many of the above permissions. I very much appreciate his wisdom and help as the book took shape. I also thank my Project Coordinator at Springer, Mr Srinivasan Manavalan. I am also very grateful to my Project Manager, Kali Gayathri, for careful and thorough attention to the final production.

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Contents

1

Introducing Moth Variety and Diversity . . . . . . . . . . . . . . . . . . . . . 1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2 Richness and Variety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.3 Distinguishing and Counting Species . . . . . . . . . . . . . . . . . . . . 1.4 Noticing Moth Diversity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1 1 2 8 12 18

2

Moth Ecology and Conservation Importance . . . . . . . . . . . . . . . . . 2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2 Specialisation and Dietary Breadth . . . . . . . . . . . . . . . . . . . . . . 2.3 Moths as Pollinators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.4 Variety in Feeding and Resources . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

21 21 22 24 27 35

3

Moth Declines and the Need for Conservation . . . . . . . . . . . . . . . . . 3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2 Detecting and Assessing Species Declines . . . . . . . . . . . . . . . . 3.3 Changes in Moth Assemblages . . . . . . . . . . . . . . . . . . . . . . . . 3.4 Dealing with Rarity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

39 39 40 43 49 59

4

Causes for Concern: Habitat Change as the Major Imposed Threat to Moths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2 Habitat Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

63 63 68 82

Causes for Concern: Confounding Threats to Moths . . . . . . . . . . . . 5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2 Chemical Pollution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3 Climate Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.4 Non-Native Species . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

87 87 87 89 99

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5.5 Exploitation of Populations . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 5.6 Light Pollution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 6

Australia’s Moths and Their Habitats . . . . . . . . . . . . . . . . . . . . . . . 6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2 Accumulating Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.3 Features of Australia’s Moth Fauna . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

123 123 124 125 134

7

A Closer Focus: Threats to Australia’s Moths . . . . . . . . . . . . . . . . . 7.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.2 Loss of Native Vegetation: A Key to Australian Moth Conservation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.3 Fire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.4 Climate Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.5 Pest Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

137 137

8

9

Moth Flagships in Australia: Focus on Single Taxa . . . . . . . . . . . . . 8.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.2 Selecting and Designating Priority Species . . . . . . . . . . . . . . . . 8.3 The Current Priority Species . . . . . . . . . . . . . . . . . . . . . . . . . . 8.3.1 Synemon gratiosa, the Graceful Sun-Moth (Castniidae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.3.2 Synemon plana, the Golden Sun-Moth (Castniidae) . . . . 8.3.3 Synemon selene, the Pale Sun-Moth (Castniidae) . . . . . . 8.3.4 Trisyntopa scatophaga, the Antbed Parrot Moth (Oecophoridae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.3.5 Attacus wardi, Ward’s Atlas Moth (Saturniidae) . . . . . . . 8.3.6 Dirce aesiodora, the Pencil Pine Moth (Geometridae) . . . 8.3.7 Phyllodes imperialis smithersi, the Southern Pink Underwing (Erebidae) . . . . . . . . . . . . . . . . . . . . . . . . . 8.3.8 Agrotis infusa, the Bogong Moth (Noctuidae) . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conservation Potential for Australia’s Moths: Focus on Wider Diversity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.2 Need for Further Survey . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.3 Interpreting the Outcomes . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . .

137 141 143 144 146 149 149 151 160 160 162 163 165 167 169 170 171 173 177 177 179 183 186

Contents

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Bringing Potential to Practice: A Future for Australia’s Moths . . . . 10.1 Introduction: Some Major Concerns . . . . . . . . . . . . . . . . . . . . . 10.2 Habitat Management Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.3 Captive Rearing and Translocation . . . . . . . . . . . . . . . . . . . . . . 10.4 Moths in Australia: Conservation Targets or Passengers? . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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189 189 201 205 207 216

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221

Chapter 1

Introducing Moth Variety and Diversity

1.1

Introduction

Lepidoptera, although by far the smallest of the four megadiverse insect orders with a complete metamorphosis, is also by far the best known. Exceeded in species numbers by Coleoptera, Diptera and Hymenoptera, they are still astonishingly diverse, with many species still to be distinguished clearly and named. Even for the relatively well-documented fauna of North America, a recent estimate implied that a third of the Lepidoptera fauna is still undescribed. Globally, perhaps 160,000 species of butterflies and moths have been named, and Powell (2009) conjectured that the world fauna of Lepidoptera ‘certainly exceeds 350,000 [species] and may be much larger’, much of this diversity being attributed to evolutionary radiations with flowering plants over long periods. Indeed, Lepidoptera are the overall largest evolutionary array of herbivorous animals, and much of their current diversity reflects subtle patterns of adaptations, co-evolution and specialisations with plants. Kawahara et al. (2019) considered Lepidoptera ‘one of four major super-radiations of insects’, which play major ecological roles in almost every habitable terrestrial ecosystem. They are by far the predominant group of herbivorous insects, associated mostly with vascular plants throughout the world and within which moths are by far the more numerous component. Their roles as consumers (larvae mostly as herbivores or detritivores and adults on floral nectar) and pollinators, often in very specific contexts, render Lepidoptera critical in sustaining ecological structure and function in many terrestrial ecosystems. Most Lepidoptera are terrestrial, but a few are associated with freshwater plants and are sometimes thought of as ‘aquatic’. It is widely agreed, as noted above, that their diversity and diversification are linked strongly with the radiation of the angiosperms, on which the great majority of Lepidoptera depend. The proliferation of the angiosperms was a major global transformation that occurred throughout the mid-Cretaceous period, around 125–980 million years ago (Labandeira 2018).

© The Author(s), under exclusive license to Springer Nature Switzerland AG 2023 T. R. New, The Other Lepidoptera: Moth Conservation in Australia, https://doi.org/10.1007/978-3-031-32103-0_1

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1

Introducing Moth Variety and Diversity

As Braak et al. (2018) commented, ‘Our relationship with Lepidoptera is a complex one’. Again, ‘the Lepidoptera have a special place in human perception, culture and nature appreciation’ (Hong Kong Declaration 2007), a sentiment underpinning the need for increased conservation consideration and for this to be extended beyond butterflies to encompass the more diverse moths. To many naturalists, ‘butterflies’ and ‘moths’ are contrasted but related insect groups that have aroused very different levels of interest and attention. In part, this perceived dichotomy is because many butterflies are conspicuous, day active and amongst the largest and (for many) brightly coloured and appealing insects seen. Few people fear butterflies—they are regarded as harmless and some are seen as symbols of tranquillity and environmental well-being. In contrast, the epithet ‘moths’ can arouse very different reactions, of being pests or nuisances and objects for suppression and, at least, foregoing the wider approval typical for butterflies—but with the significant exceptions of those several groups of moths that have become diurnal and garnered parallel approval as ‘honorary butterflies’, through their accessibility to collectors and study. The Jersey tiger moth (Euplagia quadripunctaria, Erebidae: Arctiinae) on the island of Rhodes (Greece) is an important tourist attraction, where visits to view their large aestivating aggregations are advertised as to the ‘Valley of the Butterflies’ and highlighted in almost all tourist literature for the island. Conversely, a few butterflies whose larvae feed on vegetables or garden ornamentals are often disparagingly or uncritically referred to as ‘moths’: the Cabbage white butterfly (Pieris rapae, Pieridae) is commonly the ‘White cabbage moth’, for example. Collectively, around 70% of agricultural pest insects are Lepidoptera, overwhelmingly dominated by moths, some of which cause massive economic losses.

1.2

Richness and Variety

Fundamentally, butterflies are most pertinently considered as a lineage of diurnal moths nested within the complex evolutionary tree of Lepidoptera, as a rather minor numerical component of the order. They are regarded as a single superfamily (Papilionoidea), but the relationships between the skippers (Hesperiidae) and a group of butterfly-like moths from South America (Hedylidae) are still debated. If, following Goldstein (2017), all are placed together in the same superfamily, with a total of seven families to include these more doubtful groups, the ‘true moths’ comprise the remaining 41 superfamilies and about 124 families. The butterflies and most true moths are placed within the section Ditrysia, by far the richest and most ecologically varied section of the order, with some 150,000 described species and including virtually all Lepidoptera acknowledged by non-specialists. Ditrysia is the most advanced members of the order, characterised by females having separate genital and copulatory apertures and unified by (1) having a suctorial proboscis, a feature shared with some other moths and contrasting with the mandible-bearing adults of the most primitive moths, Micropterigidae, and others considered to represent the most ancestral condition, and (2) being linked strongly with

1.2

Richness and Variety

3

angiosperms, with larvae of most taxa feeding on or in vascular plants. Most larvae of the groups of more primitive moths feed on non-vascular plants or as detritivores. Few of those, however, have gained conservation attention beyond the acknowledgement of their unique biological features and, for some, their very restricted distributions and isolated taxonomic status. Phylogenetic relationships within Lepidoptera continue to be debated, but many of the groups are largely unseen other than by specialists, and most conservation interest beyond butterflies has flowed from a restricted subset of, mostly, larger moths. Practical conservation of Lepidoptera has been almost entirely focused on Ditrysia, mostly as herbivores associated with particular plant taxa or vegetation formations whose conservation needs may interlink strongly. Moths thus encompass species-rich and characteristic assemblages associated with many different, often geographically or climatically restricted, plant communities and wider environments. Within these, ecologically specialised species may become wholly or largely host plant-specific, and others be more broadly representatives of wider biomes such as forest, savannah or grassland vegetation without such well-defined feeding specificity. As those resources or environments are changed, moth species or assemblages may be affected in parallel. In some contexts, the high diversity of moths, and some ability to monitor how this pattern changes, gives them values as ‘indicators’ of changes. In common parlance, many naturalists commonly recognise three main informal categories of Lepidoptera, as ‘butterflies’, ‘macromoths’ (or ‘Macroheterocera’) and ‘Microlepidoptera’. The first two are grouped as ‘Macrolepidoptera’, and this category essentially designates those taxa that have been the major focus of hobbyist interest and study, distinguishing them in practice from Microlepidoptera, most of which are very tiny moths that have been largely ignored but are proving to be very diverse as their study progresses. Such tiny moths only rarely gain conservation attention as flagship species. One exceptional case is for one of the smallest of all moths, the Sorrell pygmy moth (Enteucha acetosae, Nepticulidae) in Scotland. The smallest British moth, with wingspan of only 3–4 mm, its sole known Scottish locality (Auchennines Moss), was threatened with destruction by landfilling to create a waste tip and was also the only Scottish site for the Bog bush cricket (Metrioptera brachyptera, Tettigoniidae). Initial publicity for the conservation campaign focused on the cricket, until the moth’s common name was made familiar through a press release by the organisation ‘Buglife’. As discussed by Stubbs and Shardlow (2012), increased public interest was important in the bog being saved. E. acetosae may be the smallest insect ever to gain such notoriety. ‘Microlepidoptera’ does not represent a natural taxonomic assemblage but is simply a ‘category of convenience’ for entomologists (Robinson et al. 1994) to include most of the smallest moths that are largely ignored by collectors but that may prove to be the most diverse components of moth faunas in many places. Somewhat anomalously, not all ‘microlepidoptera’ are small: the Ghost moths and Swift moths (Hepialidae) are indeed a primitive lineage within this category, but include some of Australia’s largest moths. As Goldstein (2017) noted, the prefixes ‘macro’ and ‘micro’ can become confusing, and not all families are allocated consistently to

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1 Introducing Moth Variety and Diversity

one or other informal category. He exemplified the large superfamily Pyraloidea (the two rich families Pyralidae and Crambidae) as ‘orphaned’ in this arrangement as ‘considered neither macrolepidopteran (except by some microlepidopterists) nor microlepidopteran (except by some macrolepidopterists’. Moth diversity probably originated in the late Carboniferous period (around 300 million years ago), through some form of small mandible-bearing adults and larvae associated with non-vascular land plants, following which Kawahara et al. (2019) suggested that the majority of Lepidoptera arose from the proliferation of lineages as the angiosperms diversified in the Cretaceous. Their most significant evolutionary innovations included the development of a tubular proboscis (sometimes ‘haustellum’) (Middle Triassic, about 241 million years ago) and the butterflies becoming diurnal (Late Cretaceous, about 98 million years ago). The key development of the suctorial proboscis, now most closely associated with obtaining nectar from flowers, is regarded widely as a major promoter of diversification and may have been preceded by using the structure to obtain water. Kawahara et al.’s analysis also suggested that the earlier larval feeding habit was endophytic (feeding within plants), with feeding on the outside of plants as a later development. Many moths are nocturnal, and this is presumed to be the ancestral habit in the order—supported by the great diversity of auditory structures (‘ears’) amongst adult moths and which are believed to be bat-detecting ultrasonic hearing organs. Connor and Corcoran (2012) categorised the bat–moth relationships as ‘one of the most sophisticated predator-prey interactions known’, and the intricacies of how flying nocturnal moths avoid or counter bat predation has led to the elucidation of some very intricate behaviour patterns. However, the long-held idea that the diurnal habit in Lepidoptera arose through attempts to avoid bat predation at night has been queried, not least because some of the separate origins of hearing organs happened before bats diversified. Other explanations might be valid. Thus, Kawahara et al. (2019) suggested that auditory organs may have developed for broader environmental surveillance before being refined later for bat detection. Likewise, butterflies became diurnal before bats proliferated, perhaps enabling them to capitalise opportunistically on the resources (notably nectar) provided by day-flowering plants. A number of moth lineages are also predominantly diurnal, and some are commonly included in surveys of butterflies for ecological studies where they can be appraised with little additional effort. Collectively, these have provided much valuable foundation information for conservation. Those lineages differ greatly in their local incidence, richness, ecology and vulnerability. They also comprise some of the moth groups with the greatest historical data record—much of it from collector ‘lore’—against which more recent trends can be evaluated. Other factors contribute to the practical importance of Lepidoptera in conservation, as (1) being a predominant group of herbivores, they play central roles in food webs and are significant prey for many insectivorous consumers, including birds, mammals, reptiles and invertebrates; that herbivory also links intricately with the development of angiosperm defence mechanisms, with much feeding specificity of Lepidoptera related to plant chemicals as deterrents or feeding cues, and considerable co-evolution between consumer and food plant; (2) linked with this, many adult

1.2

Richness and Variety

5

Lepidoptera are key pollinators (many of them specific) of angiosperms: moths are amongst the most important nocturnal insect pollinators (Macgregor et al. 2015; Hahn and Bruhl 2016), and some, indeed, have become ‘pollinating seed parasites’ whereby they both pollinate and oviposit in the flowers, where their larvae subsequently feed in developing seedheads (p. 26) as ‘nursery pollinators’; (3) they are hosts to enormous numbers of parasitoids, Hymenoptera and Diptera, amongst which Ichneumonoidea, Chalcidoidea (two enormous groups of parasitoid wasps) and Tachinidae (flies), in particular, have become extremely diverse. Knowledge of the intricate and often highly specific associations between parasitoid and host is still very incomplete; and (4) because many moths have been reared by hobbyists over the years, the larvae (caterpillars) and other early stages of many taxa can be recognised and associated clearly with corresponding adults. As a result, samples of larvae and adults can both be interpreted to contribute to inventory studies and diversity estimates, in some cases (most notably in the northern temperate areas) with reasonable knowledge of voltinism, seasonality and resource needs of many species of the local fauna. The cumulative experience of rearing numerous species provides a unique body of information that can be applied to rearing other taxa of conservation concern. Their participation in all these ecological themes emphasises the wider importance of moths in conservation, including sustaining the integrity of many natural communities through the interactions to which they are vital. This background is the main theme of the next chapter. Especially for Britain and Western Europe, and much of North America, that background is extensive, but a lesser framework elsewhere can draw usefully on that knowledge and experience. Cases and contexts from Britain or North America are indeed relevant to Australia in displaying the principles and information on which conservation need can be assessed and management planned and monitored. Novel and unexpected discoveries continue to elaborate the richness and peculiarities of many regional moth faunas. In Australia, for example the tiny Enigma moth, Aenigmatinea glatzella, discovered on Kangaroo Island, South Australia, represented an entirely new family of primitive-tongued moths, as the first such family designated in recent years (Kristensen et al. 2015). Almost every region of the world contains endemic moth taxa of phylogenetic significance and wider taxonomic radiations that reflect local environmental conditions. Local moth faunas can thus be very characteristic. Regional endemism and local endemism are both frequent, and diversification in some higher taxa occurs as conditions suit. Many moth families are distributed very widely, some globally, but others are far more restricted. Moth families differ greatly in size, adjudged by the number of species recognised. Using Goldstein’s (2017) tabulation to indicate this variety, 24 of the 131 listed families of Lepidoptera contained 10 or fewer species, 36 included 10–100 species and 28 contained more than 1000 species. From the same source, the five richest families (in descending order) were Erebidae (24,569 species), Geometridae (23,002), Tortricidae (10,387), Crambidae (9666) and Pyralidae (5921). Numbers continue to change, but this general relativity is likely to persist.

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Introducing Moth Variety and Diversity

The major groups of moths (whether superfamilies or families) thus differ greatly in the numbers of species they contain, with some large moth families far outnumbering all butterflies in richness, and the real diversity of some families is still largely conjecture. At present, butterflies and ‘macromoths’ comprise about two-thirds of described Lepidoptera species but represent only a quarter (34 of about 135, the precise number differing slightly across different classification systems) recognised families and, as Brito et al. (2016) noted, most regional surveys of Lepidoptera have largely or completely omitted microlepidoptera, so that their richness may have been vastly underestimated. Especially in the tropics, numerous species await discovery and description even amongst the more popular macromoths; for the microlepidoptera of south-east Asia, Robinson et al. (1994) reported about 6000 described species but commented that those still to be discovered were likely to comprise ‘at least the same number again’. Similar suggestions could apply to the micromoths of many other tropical/subtropical regions and ecosystems. Such uncertainties flow from a combination of inadequate taxonomic attention and incomplete sampling. These hindrances are not restricted to those underdocumented regions: even for Europe, with the world’s best-accounted moth fauna, some groups of microlepidoptera are not fully known. For example, ‘One of the major problems in Gelechiidae taxonomy is the general lack of experts’ (Huemer and Karsholt 2018). That comment was made in a revision of a complex genus of this family, the tiny species of Megacraspedus, in which 22 of the 44 new species described were from Europe, suggesting that Europe may indeed still be ‘an unexpected frontier for biodiversity exploration’, contrary to much popular belief that this fauna is almost completely known. However, the micromoth faunas of much of the rest of the world are far more unexplored! In essence, they remain intangible for sound species-focused conservation evaluation so that in Australia (and many other places!) practical conservation attention devolves on the larger and more conspicuous moths that have been traditionally more attractive to hobbyists, are generally more straightforward to recognise and identify, and to which the foundation knowledge from related butterfly studies can be applied most easily. In this context, only, the Hepialidae alone amongst the primitive moths become ‘honorary macromoths’ from their long interest to collectors. Other ‘micromoths’ attracting notice are mainly those with unusual biology or habits that lead to wider notoriety. The moth families that have contributed the most conservation interest are listed in Table 1.1 to, nevertheless, demonstrate the broad ecological and geographical portfolio of attention. However, within Australia, a number of endemic or near-endemic moth families have not yet stimulated such concerns (Chap. 6). Others (such as Lasiocampidae and Notodontidae) are listed because of interest in other parts of the world that could in due course apply to related Australian taxa. The other families listed contain species of conservation concern within Australia, although this may differ from concerns elsewhere. Saturniidae, for example, is a leading flagship group for conservation elsewhere, but is not diverse in Australia, and the regionally characteristic representation of endemic Castniidae (sun-moths) has become a leading conservation concern (Chap. 8). The largest families listed, Erebidae, Geometridae and Noctuidae, all contain numerous species, and changes in their

1.2

Richness and Variety

7

Table 1.1 Key focal moth families on which wider conservation interest has been founded and developed Family Hepialidae Cossidae Castniidae Zygaenidae Lasiocampidae Saturniidae Sphingidae Geometridae Notodontidae Erebidae Noctuidae

Common name(s) Ghost moths, swift moths Goat moths Sun-moths Burnets, foresters Lappet moths Silk moths Hawk moths Loopers, geometers, emeralds, carpets, waves Prominent moths, processionary moths Tiger moths, footmen, tussock moths, underwings Armyworms, cutworms, owlets, underwings

local richness, ecological variety and assemblage composition with environmental conditions, elevation and latitude accord them important wider roles in characterising and monitoring such influences. In particular, the hyperdiverse Geometridae are amongst the most abundant ‘larger’ moths in many tropical and temperate region habitats; most are nocturnal and sampled easily by light trapping (p. 45), rendering them useful as putative indicator taxa in such comparative studies (Beck et al. 2017). Pyraloidea (the families Pyralidae and Crambidae) are also very diverse and have similar values, as demonstrated through surveys in Australia’s eastern rainforests (Kitching et al. 2020). For example, interpretation of the >100 species of Pyraloidea found in Eungella National Park, Queensland, revealed distinctive lowland and upland assemblages, distinct from around 700 m asl. Most taxa in spring samples were from lowland sites, but more even distribution occurred in summer. Although some of these groups are considered to be ‘well known’ in Europe and North America, in particular, considerable ambiguity prevails elsewhere and evaluating their conservation needs can become speculative. Many historical descriptions of even the largest moths from more remote parts of the world have been based on very limited material—in many cases the type specimen or series from which the species was described remains the only known representation—rather than from well-planned systematic surveys, and the records of species (and purported absences of other species through failure to report them) are largely serendipitous. Some moth species, however, appear to be genuinely scarce. The Menetries’ tiger moth (Arctia menetriesii, Erebidae; Arctiinae) occurs widely across the Eurasian taiga zone from Finland to eastern China, but over this vast range fewer than 100 specimens have been recorded since the moth was described in 1846 (Bolotov et al. 2022). Much of this range is remote, uninhabited and difficult to explore, but data accumulated up to 2020 implied that the ‘exceptional rarity’ of this species may be real and that the moth’s ecology remains very poorly documented.

8

1.3

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Introducing Moth Variety and Diversity

Distinguishing and Counting Species

Enumerating species, an exercise that many people regard as somehow fundamental in conservation but essentially a tool for helping to interpret ‘biodiversity’, depends on how ‘species’ are defined and the need for that definition to be consistent. For Lepidoptera (and any other insect group!), different specialists are likely to hold different views over boundaries between closely related life forms and to have different levels of experience with their subjects in the field. No firm overall figures for moth species richness are available, but several workers have attempted to assess Lepidoptera richness by summarising numbers of descriptions and synonyms. Thus, Pogue (2009) noted an overall total of 155,181 species, and in a later edition of the same work, Goldstein (2017) increased this to 157,761. Pogue noted the uncertainties of any such estimates, in comparing the numbers of ‘new’ species and synonyms (by extracting names from existing valid species listings) based on Zoological Record entries for each year from 1995 to 2006. Over the period, 11,819 new species descriptions were accompanied by 5041 synonyms, for a net increase of 5778 species. In 1 year (1997), however, synonyms (1244) considerably outnumbered new species (892). Such numbers of synonyms may surprise: part of the reason is simply that many of the larger moths have been described several times in the past, reflecting geographical and infraspecific variations leading to a tendency for individuals differing in appearance or from novel localities to be described as new. As the more critical examination has clarified the nature of that variation within species, many of the names have been ‘sunk’ as redundant, with the earliest published name given preference. Most smaller moths have not been as intensively collected, and the problems of multiple descriptions are far less (Solis and Pogue 1999). Relatively few microlepidoptera have been described more than once—but very careful appraisal is still necessary! Most figures quoted for numbers of moth species are based on morphologically distinct units, separated by defined differences in physical features and structure, as the predominant and ‘traditional’ way to distinguish these entities. Estimates for many families are likely to be increased substantially in response to the numbers of entities revealed by approaches such as DNA barcoding, through which numerous ‘cryptic species’ are being revealed in many insect groups, and the marriage of morphological and DNA studies progressively clarifies their status and integrity. Two notable Australian studies demonstrate the kinds of advances that are becoming progressively common: 1. The potential for advancing knowledge of Australian moth diversity by DNA barcoding was advanced massively by the ‘Barcode Blitz’ through species represented in the Australian National Insect Collection (ANIC), Canberra (Hebert et al. 2013). ANIC then included around 2 million specimens of Lepidoptera, with representatives of almost 90% of the known fauna and ‘thousands of potential species’ distinguished on morphological grounds but not described. The aim of this exercise echoed earlier sentiments that (in Hebert et al.’s words) ‘Without formal documentation . . . species-in-waiting contribute nothing

1.3

Distinguishing and Counting Species

9

towards a deeper understanding of the distributional patterns and diversity of the Australian fauna’, including their conservation need. Over several visits to ANIC, a team of workers systematically processed DNA samples from a single leg from each of 41,560 specimens representing 12,699 species and assessed the effects of specimen age, body size and collector treatment on the outcomes, as well as intraspecific variation. The public availability of this information (as two files in alphabetical sequence of family names: dx.doi.org/10.5883/DS-ANIC1A [Adelaide–Noctuidae], dx.doi.org/10.5883/DS-ANIC1B), accompanied by images of each specimen and its locality data, provides what is essentially a national database as a foundation for assessing butterfly and moth diversity and for correct placement of additional material as it is accumulated. 2. Even for the best-documented and most popular moth families, DNA barcoding can reveal unexpectedly high diversity and the presence of well-categorised cryptic species. The Australian hawk moths (Sphingidae), as elsewhere, have long been popular with hobbyists, and a recent monograph (Moulds et al. 2020) has strengthened that popularity further. An earlier study (Rougerie et al. 2014) explored the DNA barcodes of more than 1200 specimens from Australia, and in order to detect affinities, this total also included presumed conspecific or closely related moths from further afield. The survey revealed greater levels of endemism than supposed previously and disclosed hitherto overlooked cryptic diversity with the extra-Australian information leading to queries over a number of species boundaries. Perhaps the most far-reaching outcome was to show that the previously well-known Convolvulus hawk (Agrius convolvuli) almost certainly represented two species, with ramifications for its treatment in some pest management programmes in the region. Altogether, 18 species—about a quarter of Australia’s hawk moth fauna—raised questions about their correct delimitation and status, and the true distribution of each. Soberingly, therefore, even such a ‘well-known’ taxon can reveal the extent of the Linnean and Wallacean shortfalls (p. 191) in understanding biodiversity (Rougerie et al. 2014). As a further example of increased richness evident from DNA barcoding, the tropical Andes of South America have long been known to harbour numerous species of Geometridae—many of them in forest areas that are under threat from clearing—with the region considered the ‘global hotspot’ for this moth family (Brehm et al. 2005). Surveys of a small area of the Andes in Ecuador, for example, yielded more species of Geometridae than reported from the whole of Europe. DNA information distinguished 1857 putative species, a substantial increase from the 1010 species reported earlier from morphological characteristics (Brehm et al. 2016). About a third of these ‘species’ were represented by singletons, giving the strong suggestion of further diversity being present. The new information also changed perceived patterns of elevational distribution. In contrast to the more usual pattern of a ‘hump’ of richness at intermediate elevations (Beck and Chey 2008), little difference was found over the range of 1000–3000 m. Focusing more deeply on Andean Geometridae, the genus Eois (Larentiinae) is known in Australia and the African tropics but is far more diverse in the Neotropics,

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1 Introducing Moth Variety and Diversity

and local diversity was studied there by DNA barcoding of specimens collected in a small reserve (the Reserva Biologica San Francisco) in Ecuador, where an earlier extensive light-trapping survey yielding >3000 individuals had led to the recognition of 102 species on ‘traditional ‘grounds: the number of Eois species was increased to 154 (Strutzenberger et al. 2011), or even to 166 species on another analysis. Many of the additional taxa were from previously undersampled ravine forests, but Strutzenberger et al. also suggested that another hundred species may await discovery there. Implications of these, and related studies from various parts of the world, have wide conservation importance for moths, beyond estimating ‘species numbers’, such as (1) some species believed to be widely distributed generalist feeders are revealed as complexes of localised specialist species, each with different larval food plant preferences or specificity, or other individualistic features; and (2) presumed intraspecific variations in appearance also reflect the presence of more consistent co-occurring forms. DNA barcoding is a valuable tool in assessing moth (and other insects) diversity in poorly documented rich assemblages in which numerous undescribed species occur. It can document the diversity and validly compare diversity and abundance (through consistently recognisable Barcode Index Numbers: ‘BINs’) and, as only a very small amount of tissue is needed for treatment—for Lepidoptera, commonly only a single leg is used, as in the survey noted earlier—the donor specimen can be retained as a standard pinned specimen documented and perhaps photographed for future reference. Much of the future of moth species delimitations and descriptions will reflect combinations of morphological and DNA barcode information in separating the units involved. Likewise, because larvae and adults can be associated without the need for rearing, much ecological data—such as food plant records—can be accumulated by intelligent use of DNA barcoding. The extent of novel information obtained from poorly known faunas was illustrated for Gabon (Central Africa), where moths collected by light traps over 4 and 7 nights, respectively, at two sites yielded more Barcode Index Numbers than the total number of moth species listed for Gabon in the most complete database then available (Delabye et al. 2018). Such studies are a sobering reminder of the poor formal knowledge of many tropical moth faunas. Further, 59% of the 1385 barcode numbers (taken as a surrogate for species) in Gabon were from singletons, again reflecting that sampling was insufficient for any reasonably complete evaluation of moth diversity. Many taxonomic groups are still to be examined critically by such methods, which in general tend to increase the numbers of distinct life forms, often termed ‘evolutionarily significant units’, that may need conservation. In practice and for the foreseeable future, any moth species that becomes a taxonomic target or flagship for conservation will almost inevitably represent a ‘traditionally defined’ species or consistently recognised subspecies. Not least, the consistent and accurate recognition of these entities by non-specialist observers may be critical in monitoring and evaluating a conservation enterprise. The latter status (often with a formal trinomial name designating subspecies status) is frequently targeted amongst butterflies, based on the local incidence of phenotypically distinct forms that become threatened, even

1.3

Distinguishing and Counting Species

11

when the parental species as a whole may be secure. Considerable debate continues over the validity and relevance of the subspecies category (Braby et al. 2012) and of populations based on hybridisation between putative subspecies with adjoining and overlapping ranges (as for the Sword grass brown butterfly, Tisiphone abeona (Nymphalidae) in eastern Australia: Braby 2000), in conservation listings. However, whenever epithets such as ‘subspecies’ or ‘host races’ are applied (even uncritically) to moths, there is some chance that multiple species may be involved within that implied variety. ‘Host race’ refers to segregates of a putative species that has a relatively broad host plant range but are each found mostly on a single part or subset of that range and are apparently more specific feeders. One classic case is of the European Small ermine moths (Yponomeuta, Yponomeutidae) in which putative species have been differentiated largely on food plant preferences or restrictions. The sibling taxa are now regarded as distinct in having different pheromone systems and enzyme loci (Menken 1989) but are morphologically almost indistinguishable. Such quandaries over precise identifications are frequent, and allusions to ‘complexes’ or ‘groups’ abound in moth literature. More generally, precise taxonomy for moths (and other organisms) considered for conservation has two opposing ‘perils’ for accurate identification (Patrick et al. 2010). First, failing to distinguish entities that are truly distinct can mean that deserving taxa may not be conserved and that the habitats that support them are undervalued. Second, if named entities are not truly distinct, scarce conservation resources may be misdirected, and unnecessary difficulties arise in identifications. In practice, as Patrick et al. commented ‘finding the middle ground may not be easy’. For Notoreas spp. (Geometridae) in New Zealand (p. 48), allopatric populations can differ clearly in size, wing pattern and habitat needs, leading to ambiguities in whether these populations can be distinguished sufficiently to treat them as separate taxa (Patrick et al. 2010). Isolated moth populations may gain additional significance as being genetically distinctive and, so, ‘evolutionarily significant units’ (defined broadly as populations or sets of populations with a distinct evolutionary heritage) some of which may be distinct species. In contrast to butterflies, named subspecies or other infraspecific entities in moths have not been distinguished widely as separate conservation targets: one such focus in Australia is the Southern pink underwing moth (Phyllodes imperialis smithersi, Erebidae, p. 170), but interpreting the evolutionary and conservation relevance of such variety is a complex exercise. In many cases, consistent genetic differences across populations reflect patterns of evolution and dispersal that have led to local distinctiveness and are invaluable in tracing the species’ history— but without the implication of further taxonomic entities being involved at present. The Pitcher plant moth (Exyra semicrocea, Noctuidae) associated with Sarracenia spp. across the south-eastern US coastal plain showed clear genetic differences between populations to the west and east of the Mississippi River alluvial plain, with this acting as a significant barrier to gene flow (Stephens et al. 2011), but several different lineages were present in each major segregate. As an example, in which likely taxonomic change was more evident, the Kern primrose sphinx moth (Euproserpinus euterpe, Sphingidae) is endemic to a small area of California and is a listed ‘threatened species’ in the United States. Indeed, it

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1 Introducing Moth Variety and Diversity

was the first moth to be cited in this way and was subsequently feared to have become extinct. E. euterpe was rediscovered in a small area of the Sierra Nevada in the 1990s, and a second population found some 115 km west of this in 2002 (Jump et al. 2006). Taxonomic uncertainty occurred because the very similar Phaeton sphinx (Euproserpinus phaeton) occurred allopatrically with E. euterpe and only 27 km away: the two populations of euterpe were thus further apart than either of these from phaeton—which is widely distributed and occurs ‘across thousands of km2 of desert’ (Rubinoff et al. 2015). Genetic investigations showed that E. phaeton is distinct, but also that the two populations of E. euterpe were also very different. They shared no haplotypes, and this difference emphasised that a population-level approach to conservation is necessary, with both populations meriting active management and protection. Major threats to each differed: the original population (Walter Basin) is threatened by agricultural and housing development and the more recent discovery (Carrizo Plain) from degradation by sheep grazing and invasive weeds (Rubinoff et al. 2015). Whether the two are indeed of the same species remains uncertain, but their genetic distinctiveness demonstrates an aspect of diversity that is often unheeded—and the same study also disclosed a further, undescribed, species of Euproserpinus. Five geographically separated groups of the Golden sun-moth, Synemon plana (Castniidae, p. 162) in south-eastern Australia were distinguished genetically by Clarke and O’Dwyer (2000), with one eliciting a comment of much wider significance, namely that it ‘may be sufficiently different genetically to be regarded as a separate subspecies or race’, but with ambiguity persisting. Any such isolated populations may provide equivalent uncertainty, but have only rarely been investigated critically to determine possibly significant differences that, ideally, should be sustained as evolutionarily significant entities.

1.4

Noticing Moth Diversity

However, their constituents are defined and distinguished, and most of this variety and richness amongst moths is largely unseen by the casual observer. Most nocturnal moths (comprising some 75% of the total number of species), for example, are noticed only when they are attracted to lights and diurnal moths are often regarded as ‘butterflies’! Those moths noticed tend to be thought of as nuisances or pests, but the species causing economic damage to crops, orchards, forestry or ornamental plants (although their depredations may be very severe and demand urgent or expensive management: p. 107) are a very small minority of the total species. Rather more can cause aesthetic damage. Most described ‘damage’ to plants by moths is from larval feeding, with other pest species associated with stored products (grain, flour, dried fruit) or domestic situations (‘clothes moths’). Adults of a few species pierce soft or ripening fruit and may also cause substantial economic damage through direct spoilage and facilitating attack by bacteria, fungi and other fruit-eating insects. One such moth, Eudocima phalonia (Erebidae), is regarded as a ‘significant

1.4

Noticing Moth Diversity

13

worldwide economic pest’ (Leroy et al. 2021) through attacking more than 100 fruit crops throughout its extensive range. Conversely, some moths are regarded as beneficial to humanity. In addition to major services such as pollination of crops and ornamental plants, examples of this wider interest include the following: (1) the silk industry is founded on the now-domesticated Bombyx mori (the ‘silkworm’, Bombycidae), but a variety of Saturniidae are also used for silk production; (2) ‘Mopane worms’, larvae of another saturniid moths, the Emperor moth (Imbrasia belina), are harvested for food in rural southern Africa; they can become very abundant at times and are viewed as a valid and rewarding commercial enterprise; and (3) the ‘caterpillar fungus’, Ophiocordyceps sinensis, is endemic to the Tibetan plateau in the Himalayan region, where it parasitises underground larvae of some swift moths (Thitarodes spp., Hepialidae); infected caterpillars are harvested for a wide range of uses in traditional medicine, with many local livelihoods depending on this lucrative commodity from remote high elevation grasslands, for which little information on sustainable levels is available and impacts on the moth populations are also unknown. Declines in harvest quantity have been attributed to a combination of climate change and overharvesting (p. 109). However, the fungus has been described as ‘one of the most expensive biological resources in the world’ (Shrestha and Bawa 2013, 2015), with the global value of harvested caterpillars cited there as 5–11 billion US$/year. Less tangibly but perhaps even more importantly should their economic contributions ever be elucidated, the considerable roles of moths as pollinators and as critical components of food webs help to sustain human needs. In addition to animals such as many bats (above) and birds reported to depend on moths, the remarkable seasonal aggregations of adults of a few species are critical food resources for other significant mammals. For example, (1) Australia’s Bogong moth (Agrotis infusa, Noctuidae, p. 17) migrates over much of the south-eastern mainland to aestivate in rocky caves in the cooler alpine zone, where it is a critical food for the endangered Mountain pygmy possum (Burramys parvus) during the summer months (DELWP 2019); and (2) aestivating masses of another noctuid, Euxoa auxiliaris, in the Yellowstone National Park constitute up to a third of the annual calorific requirement of Grizzly bears (Ursus arctos horribilis) in that region of North America (White et al. 1998). Declines of Bogong moths have, for this reason alone, aroused considerable concern in Australia. Particularly for the tropics, poor knowledge of moth diversity is accompanied by a complete lack of any biological information on most of the species encountered. Knowledge of even most of the best-documented species is very incomplete. In some cases, inferences from related but better-known species elsewhere may suggest their host relationships and ways of life, but lack of specific information is a major impediment to understanding the impacts of environmental changes beyond the obvious direct loss of natural vegetation or other key resources. Even collecting sufficient moth specimens for improving inventory studies may be impracticable. Some major groups of microlepidoptera, indeed, may need laborious and timeconsuming rearing to obtain them, because adults are not attracted to light. Many Gracillariidae, for example, are not easily collected by this standard sampling

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1 Introducing Moth Variety and Diversity

technique (p. 45), and the most reliable way to obtain clearly host-associated specimens is to rear them from larval leaf mines or related substrates. Collecting mines can be laborious and, as for forest canopy species that occur in only low densities, they may be very difficult to access (Brito et al. 2016). Levels of host plant restrictions can be complex, with larvae being specific miners and the corresponding adults pollinating the same plant species. Additional complexities arise simply because the moths are tiny and difficult to examine. Related to these hindrances, Brito et al. inferred that the Gracillariidae fauna of plant-rich areas (in their survey, the Atlantic Forests of eastern South America) was likely to be far greater than currently known. For the entire Neotropical region, they reported only 185 species of Gracillariidae but estimated that ‘at least 3675’ further species await description. Such extrapolations can become difficult and are inevitably uncertain—but they also emphasise the extent of ignorance in a realistic assessment of insect diversity even in groups that people regard as ‘well known’. These gaps have wider ramifications for conservation; Brito et al.’s comment that ‘no Neotropical Gracillariidae species has been taken into account up to now from a conservation biology perspective’ can be extended easily to virtually all microlepidopteran families in any part of the world. Although largely unseen, the sheer numbers of these moths can be a powerful tool in assessing changes in assemblages or local faunas. That potential was illustrated in the relatively well-documented microlepidoptera of Western Europe by Kuchlein and Ellis (1997). That the small moth fauna of the Netherlands had been influenced strongly by climate change and undergone considerable alterations in its composition (‘The actual species composition of the fauna has changed considerably as a result of colonisation and extinction’) has far wider geographical relevance, but parallel assessments elsewhere involving these moths are unlikely to proliferate in the near future. As might be anticipated for such prominent herbivores, local flora is linked strongly with local moth diversity (simplistically, a high plant diversity is accompanied by a high herbivore diversity, and scarce or locally restricted plants may harbour equally restricted moths) and, unlike many other insect groups, the freeliving larvae of many moths can be identified to at least family level, and many can be reared to confirm identity from the adult moth. Both adult and larval stages can thereby contribute to ecological studies. Larvae of many externally feeding larger moths and microlepidoptera are polyphagous or oligophagous, but others are strictly monophagous. Most of the specialised internal feeding microlepidoptera (leaf miners, stem borers) are monophagous. However, the lack of biological information on moths in many parts of the world where they are most diverse limits interpretations of their richness; for most, for example, no information is available on preferred or necessary host plants other than by chance discovery. This contrasts markedly with well-studied faunas, such as moths of Great Britain, where studies and hobbyist interest over more than two centuries have provided detailed knowledge of almost every species to provide a sound template of resource needs and fine-scale distribution against which more recent changes can be assessed. However, even there, the ecology of some species is still inadequately known. In England, the Marsh moth (Athetis pallustris, Noctuidae)

1.4

Noticing Moth Diversity

15

now occurs only on some coastal dune grasslands in Lincolnshire and is one of the moths listed under Britain’s ‘Biodiversity Action Plan’. Under the more local County Action Plan, it is noted that ‘the main threat is loss through ignorance’ because so little is known of its ecology as a basis for site management. Nevertheless, some important generalisations about particular moth groups have been implied. Janzen (1984) discussed the biological contrasts between the two most ‘popular’ and large-bodied moth families (silk moths, Saturniidae; hawk moths, Sphingidae, sometimes considered to be sister groups), in Santa Rosa, Costa Rica, to produce general ‘caricatures’ of these families. His essay elegantly emphasises the importance of understanding moth biology in order to interpret the samples of species and assemblages within a site and for comparisons over space and time. The activity patterns, assessed as an attraction to light, differed. In this example, focusing here on adults, (1) saturniids do not feed, having only rudimentary mouthparts; the females are far larger than males and fly comparatively little; they attract mates by pheromones and lay a substantial proportion of their eggs the first night after mating; and they are short-lived, surviving for about a week; males are also short-lived; most females arrived at light during the first few hours, mostly before midnight, and most males arrived in the second half of the night. In contrast, (2) sphingids feed from flowers, using their long proboscis to obtain nectar, many of them whilst hovering; they are long-lived and strong fliers and can track food over a greater distance, using visual cues to locate food; most species arrived at lights before midnight, with females continuing to arrive throughout the night. Larval feeding preferences also differed. Typically, these moths may be thought of as exhibiting the contrasting strategies of ‘capital breeders’ (Saturniidae, with adult reproduction drawing on resources accumulated during the larval stage) and ‘income breeders’ (Sphingidae, with reproduction fuelled by continuing feeding throughout adult life), for long recognised as patterns of resource use (Jonsson 1997). Intriguingly, as discussed in the context of forest losses in Amazonia, these strategies may imply different responses to landscape disturbance (Correa-Carmona et al. 2021)— the more sedentary saturniids showed a far more significant response to disturbance than the more mobile hawk moths that are able to track resources across their environment. Simple family-level conclusions, however, may become complicated by greater intra-family differences. The Sphingidae includes both capital- and income-breeding taxa, leading to the hypothesis that the former (largely species of the subfamily Smerinthinae) might be more common and richer in stable habitats and the latter better adapted to thrive in disturbed or ephemeral environments (Beck et al. 2006). That suggestion arose from the relative frequency of Smerinthinae and the income-breeding Macroglossinae across a long suite of samples in south-east Asia, across three categories of habitat with different levels of disturbance (Fig. 1.1) treated as a gradient of disturbance impacts along which frequency of Smerinthinae declined and Macroglossinae increased. However, some other findings differed. Using a more basic dichotomy of undisturbed and disturbed habitats, but based on smaller samples, Schultze and Fiedler (2003) did not find this trend. Ignorance of such traits is far greater for most microlepidoptera, especially beyond Europe, where the patterns of discovery of Lepidoptera through hobbyist

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Introducing Moth Variety and Diversity

Fig 1.1 Influence of habitat disturbance on the relative abundance of subfamilies of Sphingidae in primary, secondary and heavily disturbed forests across south-east Asia, based on analysis of 93 local samples. Black spots, solid line: Macroglossinae; annular spots, dashed line: Smerinthinae; crossed spot, dotted line: Sphinginae (after Beck et al. 2006)

interests have been initiated most commonly through butterflies and focused on local to national faunas, so that interests of ‘the average amateur lepidopterist’ (Kristensen et al. 2007) traditionally progressed from butterflies to macromoths and in fewer cases later to microlepidoptera of his/her native fauna, rather than to butterflies of neighbouring countries. Modern ease of travel has distorted this trend, but the hierarchy of interest from butterflies downwards to micromoths persists. Elsewhere, especially throughout the tropics, the levels of uncertainty through incomplete documentation are far greater. Many of the more primitive groups of microlepidoptera are ‘rarely encountered in nature and almost every new record merits communication’ (Mey et al. 2021), as contributing to faunistic knowledge and, in some cases, helping to elucidate patterns of possible origins and relationships. Thus, Mey et al.’s discovery of a species of Micropterigidae in forests of central Vietnam was the first record from the Northern Hemisphere of a genus (Archaeopteris) known previously only from north-eastern Australia and New Caledonia and raised suspicion that it might eventually be found also amongst the largely unexplored islands over the intervening 600 km. The distinction of species, ideally named and recognisable by non-specialists, as the most tangible and popular units for conservation, is a major advantage. Lepidoptera conservation is founded in concerns for individual species and that continuing emphasis draws from precedents amongst vertebrates and vascular plants, in which individual notable species have commanded attention simply because they can be recognised, their vulnerabilities exposed, focused conservation measures can be designed and undertaken and the outcomes monitored. ‘Species’ are tangible

1.4

Noticing Moth Diversity

17

Table 1.2 Ten criteria for consideration in selecting effective flagship species for conservation (after Bowen-Jones and Entwistle 2002), with comments on the relevance Criterion Geographical distribution Conservation status Ecological role Recognition Existing usage Charisma Cultural significance Positive associations Traditional knowledge Common names

Comment Within the regional area of interest; endemism or restricted distribution may increase local importance Traditionally, high risk of extinction, but common species may also be valuable Critical or central role in the ecosystem increases benefits; provides an opportunity to explain the importance Ideally, distinctive and not confused with other species by the target audience If used elsewhere, may be a useful endorsement, but might also create mixed messages; avoid conflicts of interest Often subjective and variable (consider other novelty or interest values) Identify carefully; may provide opportunities for endorsement Increase the likelihood of effectiveness (note: strong associations are not necessarily positive) Valuable source of information; provide importunities for reinforcement and expansion May influence public perception; can change or devise to improve the public image

entities, providing a far clearer focus for conservation than more nebulous entities such as ‘communities’ or ‘assemblages’. To many people, the idea of conserving insects other than the most appealing forms (i.e. in the main, butterflies) is still not easy to embrace, and unfavourable public perceptions work against this need. Despite their vast numbers, very few species of moths have attracted individual conservation concerns. The group has considerable potential to reveal further flagship taxa to represent their diversity. In contrast, wider assemblages of moths pose very different practical problems and far less sympathetic perceptions. A number of diurnal moths and representatives of a few predominantly nocturnal families—notably larger silk moths (Saturniidae) and hawk moths (Sphingidae), as above—have also attracted priority interests, but many other larger moths and most microlepidoptera have rather little chance of fulfilling the general criteria that render ‘flagships’ useful (Table 1.2 and Chap. 7). Ability to garner community interest and support is a vital component of these (New 2011). Improving the public and political image of moths is thus a key component of their conservation, together with improving the knowledge base on which sensible conservation can be founded. The ability to reliably count and recognise species is a major advantage, so most moth groups that are very diverse and contain many very similar species are far more difficult to assess than those with fewer, conspicuous and more easily recognisable species. Thus, Saturniidae (above) often fulfil these needs in the tropics, where many local species pools are of 100 or fewer species and facilitate comparative study and long-term monitoring. The resident saturniid pool (of around 60 breeding species) of Barro Colorado Island, Panama, reflected the

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advantages of the family for study reflected in this relatively low diversity, their popular appeal, advanced taxonomy and presence of a few common species suitable for investigation of long-term trends (Basset et al. 2017). The principle of ‘counting species’, by whatever criteria, as a fundamental measure of diversity is appealing to many conservationists, with the implication that ‘high numbers’ denote ‘high importance’. Local inventories of moths are the foundation knowledge for many conservation exercises. However, no such inventory can ever become wholly definitive, because it is dynamic: numbers of moth species present at any place vary continually with immigrants and emigrants (many of them in low numbers) affecting a more dependable core total of persistent residents that is itself difficult to circumscribe.

References Basset Y, Lamarre GPA, Ratz T, Segar ST, Decaens T et al (2017) The Saturniidae of Barro Colorado Island, Panama: a model taxon for studying the long-term effects of climate change? Ecol Evol 7:9991–10004 Beck J, Chey VK (2008) Explaining the elevational diversity pattern of geometrid moths from Borneo: a test of five hypotheses. J Biogeogr 35:1452–1464 Beck J, Kitching IJ, Linsenmaier KE (2006) Effects of habitat disturbance can be subtle yet significant: biodiversity of hawkmoth-assemblages (Lepidoptera: Sphingidae) in SoutheastAsia. Biodiv Conserv 15:465–486 Beck J, McCain CM, Axmacher JC, Ashton LA, Bartschi F et al (2017) Elevational species richness gradients in a hyperdiverse insect taxon: a global meta-study on geometrid moths. Glob Ecol Biogeogr 26:412–424. https://doi.org/10.1111/geb.12548 Bolotov IN, Gofarov MY, Koshkin ES, Gorbach VV, Bakhaev YI et al (2022) A nearly complete database on the records and ecology of the rarest boreal tiger moth from 1840s to 2020. Scientific Data 9:107. https://doi.org/10.1038/s41597-022-01230-8 Bowen-Jones E, Entwistle A (2002) Identifying appropriate flagship species: the importance of culture and local contexts. Oryx 36:189–195 Braak N, Neve B, Jones AK, Gibbs M, Breuker CJ (2018) The effects of insecticides on butterflies: a review. Environ Poll 242:507–518. https://doi.org/10.1061/j.envpol.2018.06.100 Braby MF (2000) Butterflies of Australia, 2 vols. CSIRO Publishing, Melbourne Braby MF, Eastwood R, Murray N (2012) The subspecies concept in butterflies: has its application in taxonomy and conservation biology outlived its usefulness? Biol J Linn Soc 106:699–716. https://doi.org/10.1111/j.1095-8312.2012.01909.x Brehm G, Pitkin LM, Hilt N, Fiedler K (2005) Montane Andean rain forests are a global diversity hotspot of geometrid moths. J Biogeogr 32:1621–1627 Brehm G, Hebert PDN, Colwell RK, Adams M-O, Bodner F et al (2016) Turning up the heat on a hotspot: DNA barcodes reveal 80% more species of geometrid moths along an Andean elevational gradient. PLoS ONE 1(30):e0150327. https://doi.org/10.1371/journal.pone. 0150327 Brito R, De Prins J, De Prins W, Mielke OHH, Goncalves GL, Moreira GRP (2016) Extant diversity and estimated number of Gracillariidae (Lepidoptera) species yet to be discovered in the Neotropical region. Rev Bras Entomol 60:275–283 Clarke GM, O’Dwyer C (2000) Genetic variability and population structure of the endangered golden sun moth, Synemon plana. Biol Conserv 92:371–381

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Connor WE, Corcoran AJ (2012) Sound strategies: the 65-million-year-old battle between bats and insects. Annu Rev Entomol 57:21–39. https://doi.org/10.1146/annurev-ento-121510-133537 Correa-Carmona Y, Rougerie R, Arnal P, Ballesteros-Meija L, Beck J et al (2021) Functional and taxonomic responses of tropical moth communities to deforestation. Insect Conserv Divers. https://doi.org/10.1111/icad.12549 Delabye S, Rougerie R, Bayendi S, Andeine-Eyene M, Zakharv EV et al (2018) Characterization and comparison of poorly known moth communities through DNA barcoding in two Afrotropical environments in Gabon. Genome 62:96–107 DELWP (Department of Environment, Land, Water and Planning) (2019) Mountain pygmypossum operational contingency plan. DELWP, Melbourne Goldstein PZ (2017) Diversity and significance of Lepidoptera: a phylogenetic perspective. In: Foottit RG, Adler PH (eds) Insect biodiversity: science and society, vol 1, 2nd edn, WileyBlackwell, Chichester, pp 463–495 Hahn M, Bruhl CA (2016) The secret pollinators: an overview of moth pollination with a focus on Europe and North America. Arthr-Plant Interactions 10:21–28 Hebert PDN, deWaard JR, Zakharov EV, Prosser SWJ, Sones JE et al (2013) A DNA ‘Barcode Blitz’: rapid digitization and sequencing of a natural history collection. PLoS ONE 8(7):e68535. https://doi.org/10.1371/journal.pone.0068535 Hong Kong Declaration (2007) Declaration on the conservation of Lepidoptera. In: Kendrick RC (ed) Proceedings of the First South East Asian Lepidoptera Conservation Symposium. Kadoorie Farm and Botanic Garden, Hong Kong, pp 148–149 Huemer P, Karsholt O (2018) Revision of the genus Megacraspedus Zeller, 1839, a challenging taxonomic tightrope of species delimitation (Lepidoptera, Gelechiidae). ZooKeys 800:1–278. https://doi.org/10.3897/zookeys.8700.26292 Janzen DH (1984) Two ways to be a tropical big moth. Santa Rosa saturniids and sphingids. Oxf Surv Evol Biol 1:85–140 Jonsson KJ (1997) Capital and income breeding as alternative tactics of resource use in reproduction. Oikos 78:57–66. https://doi.org/10.2307/3545800 Jump PM, Longcore T, Rich C (2006) Ecology and distribution of a newly discovered population of the federally threatened Euproserpinus euterpe (Sphingidae). J Lepidopt Soc 60:41–50 Kawahara AY, Plotkin D, Espeland M, Meusemann K, Toussaint EFA et al (2019) Phylogenomics reveals the evolutionary timing and pattern of butterflies and moths. Proc Nat Acad Sci 116: 22657–22663 Kitching RL, Ashton LA, Orr AG, Odell EH (2020) The Pyraloidea of Eungella: a moth fauna in its elevational and distributional context. Proc R Soc Qld 125:65–79 Kristensen NP, Scoble MJ, Karsholt O (2007) Lepidoptera phylogeny and systematics: the state of inventorying moth and butterfly diversity. Zootaxa 1668(10):21. https://doi.org/10.11646/ zootaxa.1668.1.30 Kristensen NP, Hilton DFJ, Kallies A, Milla L, Rota J et al (2015) A new extant family of primitive moths from Kangaroo Island, Australia, and its significance for understanding early Lepidoptera evolution. Syst Entomol 40:5–16. https://doi.org/10.1111/syen.12115 Kuchlein J, Ellis WW (1997) Climate-induced changes in the microlepidoptera fauna of the Netherlands and the implications for nature conservation. J Insect Conserv 1:73–80 Labandeira CC (2018) The fossil history of insect diversity. In: Foottit RG, Adler PH (eds) Insect biodiversity: science and society, vol 2, 2nd edn. Wiley-Blackwell, Chichester, pp 723–788 Leroy L, Mille C, Fogliani B (2021) The common fruit-piercing moth in the Pacific Region: a survey of the current state of a significant worldwide economic pest, Eudocima phalonia (Lepidoptera: Erebidae), with a focus on New Caledonia. Insects 12:117. https://doi.org/10. 3390/insects12020117 Macgregor CJ, Pocock MJO, Fox R, Evans DM (2015) Pollination by nocturnal Lepidoptera, and the effects of light pollution: a review. Ecol Entomol 40:187–198

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Menken SBJ (1989) Electrophoretic studies on geographical populations, host races and sibling species of insect pests. In: Lonsdale HD, den Hollander J (eds) Electrophoretic studies on agricultural pests. Clarendon Press, Oxford, pp 181–202 Mey W, Leger T, Van Lien V (2021) New taxa of extant and fossil primitive moths in South-East Asia and their biogeographic significance (Lepidoptera, Micropterigidae, Agathiphagidae, Lophocoronidae). Nota Lepid 44:29–56 Moulds MS, Tuttle J, Lane D (2020) Hawkmoths of Australia. Identification, biology and distribution. Monogr Aust Lepidopt 13. CSIRO Publishing, Melbourne New TR (2011) Launching and steering flagship Lepidoptera for conservation benefit. J Threat Taxa 3:1805–1817 Patrick BH, Hoare RJB, Rhode BE (2010) Taxonomy and conservation of allopatric moth populations: a revisionary study of the Notoreas perornata Walker complex (Lepidoptera: Geometridae: Larentiinae), with special reference to southern New Zealand. N Z J Zool 37: 257–283 Pogue MG (2009) Biodiversity of Lepidoptera. In: Foottit RG, Adler PH (eds) Insect biodiversity: science and society. Wiley-Blackwell, Chichester, pp 325–355 Powell JA (2009) Lepidoptera (moths, butterflies). In: Resh VH, Carde RT (eds) Encyclopedia of insects, 2nd edn. Academic Press, Burlington, pp 559–587 Robinson GS, Tuck KR, Shaffer M (1994) A field guide to the smaller moths of South-East Asia. Malaysian Nature Society, Kuala Lumpur Rougerie R, Kitching IJ, Haxaire J, Miller SE, Hausmann A, Hebert PDN (2014) Australia Sphingidae—DNA barcodes challenge current species boundaries and distributions. PLoS ONE 9(7):e101108. https://doi.org/10.1371/journal.pone.0101108 Rubinoff D, San Jose M, Johnson P, Wells R, Osborne K, Le Roux JJ (2015) Ghosts of glaciers and the disjunct distribution of a threatened California moth (Euproserpinus euterpe). Biol Conserv 184:278–289 Schulze CH, Fiedler K (2003) Hawkmoth diversity in northern Borneo does not reflect the influence of anthropogenic habitat disturbance. Biotropica 9:99–102 Shrestha UB, Bawa KS (2013) Trade, harvest, and conservation of caterpillar fungus (Ophiocordyceps sinensis) in the Himalayas. Biol Conserv 159:514–520 Shrestha UB, Bawa KS (2015) Harvesters’ perceptions of population status and conservation of Chinese caterpillar fungus in the Dolpa region of Nepal. Reg Environ Change 15:1731–1741 Solis MA, Pogue MG (1999) Lepidopteran biodiversity: patterns and estimators. Amer Entomol 45: 206–212 Stephens JD, Santos SR, Folkerts DR (2011) Genetic differentiation, structure, and a transition zone among populations of the Pitcher plant moth Exyra semicrocea: implications for conservation. PLoS ONE 6(7):e22658. https://doi.org/10.1371/journal.pone.0022658 Strutzenberger P, Brehm G, Fiedler K (2011) DNA barcoding-based species delimitation increases species count of Eois (Geometridae) moths in a well-studied tropical mountain forest by up to 50%. Insect Sci 18:349–362. https://doi.org/10.1111/j.1744-7917.2010.01366.x Stubbs A, Shardlow M (2012) The development of Buglife – The Invertebrate Conservation Trust. In: New TR (ed) Insect conservation: past, present and prospects. Springer, Dordrecht, pp 75–106 White DJ, Kendall K, Picton HD (1998) Grizzly bear feeding activity at alpine cutworm moth aggregation sites in northeast Montana. Canad J Zool 76:221–227

Chapter 2

Moth Ecology and Conservation Importance

2.1

Introduction

The abundance and the varied biological and ecological roles of moths involve them in enormous numbers of interactions between species in the communities they inhabit, extending through all vegetated ecosystems, and within which moth abundance sometimes gives them strong influences. Moths are a staple or primary food for numerous insectivorous birds and mammals, as well as for hordes of less conspicuous animals. Moths are thus significant players across a variety of ecological networks, with most attention paid to their participation in herbivore–plant relationships and associated mutualisms and roles as pollinators. However, moths participate also in vast numbers of host–parasitoid (usually as hosts) and predator– prey (usually as prey of numerous insectivorous animals) interactions, some of them intricate and highly specific. Representative interactions between Australian bats and moths demonstrate their variety and significance: (1) the critically endangered Southern bent-wing bat (Miniopterus orianae bassanii) may even be an important contributor to controlling agricultural pests in south-eastern Australia through feeding on moths. DNA barcoding of scats and guano from the bat’s cave roosts revealed that the diet included 67 moth species, many of them associated with agriculture (Kuhne et al. 2022); (2) DNA faecal examination of a broader array of insectivorous bats over cotton-growing areas of New South Wales suggested that the bats are selective feeders, with major cotton pest moths, notably Australian bollworm (Helicoverpa punctigera, Noctuidae) and Cotton webspinner (Acharya officinalis, Crambidae) comprising large components of the diet, again providing some control of these and other cotton pests (Kolkert et al. 2020); (3) the Granny’s cloak moth, Speiredonia spectans (Erebidae), occurs in caves, mostly in eastern Australia, used also as diurnal roosts by a variety of insectivorous bats. The moth is highly sensitive to calls of some bats and can avoid significant predation (Fullard et al. 2008), but cannot respond to the exceptionally high echolocation frequencies of the Dusky leaf© The Author(s), under exclusive license to Springer Nature Switzerland AG 2023 T. R. New, The Other Lepidoptera: Moth Conservation in Australia, https://doi.org/10.1007/978-3-031-32103-0_2

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nosed bat (Hipposideros ater) and may be highly vulnerable to predation by that species. The collective functional importance of moths in sustaining complex interaction networks is still to be appreciated fully, but extends far beyond obligatory bipartite associations exemplified by ‘specific herbivore or pollinator-specific plant partnerships’ widespread amongst moths, to concerns over declines of common generalist species important in sustaining a variety of ecosystem services and roles. Such declines, signalled widely from well-documented faunas such as the United Kingdom (Conrad et al. 2006) and the Netherlands (Groenendijk and Ellis 2011), suggest the likelihood of parallels elsewhere and which—despite lack of firm evidence— may have far-reaching ecological impacts. The sheer diversity of these predominantly herbivorous insects—attributed widely to evolutionary radiations in concert with those of flowering plants—ensures that many such interactions are indeed highly specific, and the roles of particular moth species are often correspondingly restricted. Loss of apparently inconspicuous moths may have far-reaching (and usually incompletely known) consequences, and it is sometimes doubted whether their specific roles can be substituted by other species. A few moths are regarded as ‘keystone species’ to emphasise their central ecological roles in driving or significantly affecting the communities they inhabit. The flightless species of Pringleophaga (Tineidae) on the Sub-Antarctic Islands of the South Indian Ocean Province are one such example. Caterpillars of Pringleophaga marioni on Marion Island are responsible for much nutrient turnover (Haupt et al. 2014) within a detritus-based food web. Haupt et al. quoted that the rate of nutrient mineralisation averaged 17% greater than when caterpillars were absent and that they may process more than 100 kg/ha/year of dry litter mass on the island.

2.2

Specialisation and Dietary Breadth

Levels of moth–plant (or other interaction) specificity may often be higher than assumed initially, and erosion of the interaction through impacts on any participant leads to wider change. Some cases of highly specific interactions are well known— either between larvae and food plants or between adult moths and the flowers they pollinate, as examples. Such highly specific cases are cited frequently as examples of ‘co-evolution’, with the inevitability that the fate of one participant will affect the other(s) and may hasten or lead to co-extinction. One such classic example is the Madagascan orchid (Anagraecum sesquipedale) seen by Charles Darwin (1862), with its corolla some 30 cm long leading him to claim that its flowers could be pollinated only by a moth with a correspondingly long proboscis that could reach the nectar. No such moth was then known from Madagascar, but the hawk moth Xanthopan morganii (Sphingidae), reported there first in 1908, has recently been confirmed by video recording to be the pollinator of this orchid (Arditti et al. 2012). No other pollinator is known for this spectacular orchid, and it seems that its survival depends wholly on that of the moth.

2.2

Specialisation and Dietary Breadth

23

The most frequently expressed dimension of ecological specialisation amongst insect herbivores is simply the breadth of their diet. Extreme specialisation is represented by monophagy (and reflects vulnerability through strict dependence on a single food species) and generalisation by broader polyphagy (with greater opportunities to adopt other foods should any particular host plant decline). Assessing the extent of polyphagy or, conversely, proving monophagy (or related oligophagy, feeding on a few related plant species) draws on accumulated historical records of food plants and current investigations. Careful interpretation is necessary: as Ballesteros-Meija et al. (2020) noted, reliance on historical records for assessing moth dietary breadth needs several precautions—some very difficult to evaluate. Amongst other caveats, they noted that (1) many published identifications of host plants are made by non-botanists and in numerous cases some doubts over accuracy may occur, especially amongst ‘difficult’ plant groups and from changes in recent taxonomic revisions; (2) the same reservation applies to some moth names. Even accurate plant names may not be associated precisely with members of cryptic complexes of moths not recognised at the time records were made. BallesterosMeija et al. noted the case of Saturniidae, nominally well-known but for which more than 1500 new species had been described in the previous decade, largely as a consequence of an investigation by DNA barcoding. Members of species complexes may have very different feeding specialisations and dietary breadth; (3) a record of food plants reflects information up to the time of its completion, not necessarily complete documentation, so may still be very incomplete; (4) a record of a host plant does not necessarily equate to feeding or indicate ‘preference’ or ‘frequency’ of use in relation to other hosts in the same area; in some cases, the larva may simply have been resting on the plant (perhaps even having dropped onto it from above), with no other functional association; (5) the level of polyphagy may differ across populations of the same moth species; and (6) local availability of food plants restricts the evaluation of polyphagy—as Ballesteros-Meija et al. (2020) noted, a caterpillar ‘cannot be polyphagous on species of plants that are not present’. The lack of finescale distribution mapping of many potential host plants inevitably complicates awareness of the distributions of their consumers. Nevertheless, assumptions of the opposite extreme, monophagy, are often difficult to validate, and extrapolations from literature records alone can be misleading. A further caveat is that not all acceptable food plants are likely to be equally suitable, variously affecting survival, growth rate, size, and adult viability and fecundity. Likewise, seasonal suitability or acceptability of a plant as insect food may differ according to the plant chemicals present. Lists of food plants compiled from field observations may also perpetuate errors of identification, as above, but also endorse the accidental, transient or casual presence of larvae or the values of hosts that are used only rarely. Use of introduced or adventive plant species by moths is also widespread and their importance as hosts may increase as native host species decline or these others become predominant—but the extent of alien plant use by native Australian moths is not fully clear; alien plants may be either a threat or benefit in different circumstances (p. 103).

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Closely related moth species can differ markedly in their host plant usage, to provide a collective wide host range. For the large geometrid genus Eupithecia (the ‘pugs’, for which 190 species were assessed), recorded hosts comprised 62 families from 22 orders of dicotyledonous plants and three orders of monocotyledons and gymnosperms. Oligophagous species predominated (almost 60%), with fewer than 27% being monophagous (Mironov 2014). Reiterating earlier sentiment, Mironov aptly commented that ‘the knowledge of trophic specialisation of many phytophagous species is still quite limited’. However, as discussed by Hopkins et al. (2002) for several groups of insect herbivores in Britain, any insect that is specific to feeding on a narrowly distributed or otherwise rare plant must itself be rare and cannot occur elsewhere. There was a strong tendency for rare plants to support rare herbivores, many of conservation interest through that rarity or restriction, and for more common plants not to host species of concern. In Australia, several rare moth species are indeed monophagous on highly restricted plants or have well-defined host plant spectra. Examples discussed elsewhere include Nemotyla oribates (p. 94), Dirce aesiodora (p. 169) and Proditrix nielseni (p. 129), for all of which host plant distribution is a key to focusing conservation status and need. That a high proportion of moth species may have a restricted suite of larval food plants, rather than being polyphagous, suggested that moths can be ‘winged proxies for a tract’s flora’ (Duran et al. 2022) and so have values as ‘indicators’ (p. 90). Within any herbivore assemblage, the species are likely to differ considerably in their levels of polyphagy and also their opportunities to gain access to different plants, with even the most acceptable food plant species varying in attractiveness, suitability, distribution and seasonal availability. The widespread presumption that herbivore (such as moth) richness is linked strongly with plant richness is not always valid. For the Geometridae (total of 279 species) of Mount Kilimanjaro, Tanzania, this possible direct relationship was weak and regarded as ‘overly simplistic’ (Axmacher et al. 2008), with most relationships more indirect and influenced by factors such as temperature and humidity. However, other studies, such as an analysis of the Geometridae in Malaysian forests (Intachat et al. 1997) indeed inferred that this relationship was strong. Such postulated relationships are clearly difficult to evaluate. Restrictions of feeding habits by moth larvae are complex and varied, as are the relationships between adult moths and flowers. They emphasise that the twin suites of interactions involving larvae or adults may both be relevant in conservation. Both may involve intricate behaviour and co-adaptations and extend to processes such as dispersal, oviposition site selection and other aspects of resource access and use.

2.3

Moths as Pollinators

Reflecting a variety of activity patterns, particular moths may be predominantly diurnal or nocturnal, but the latter have collectively been designated ‘the major nocturnal pollinators of flowers’ (Macgregor et al. 2015) across many different

2.3

Moths as Pollinators

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Table 2.1 Eight categories of ‘evidence’ advanced to support moth pollination, ranked from least conclusive (unknown) to most conclusive (experimental) (Buxton et al. 2018) Evidence category Unknown Inferred Trace Visitation Contact Pollen on moth bodies Deposition Experimental

Description Unclear what evidence is available to support the claim Pollination inferred from floral syndromes Presence of moth scales or hairs on the stigma of flowers Moths observed visiting or foraging on the flower, or were caught on the flower Moths observed making contact with the sex organs of the flower Pollination inferred from the presence of pollen on captured moths Pollen observed to have been deposited on the stigma by moths Effective pollination shown by the use of pollinator exclusion experiments

ecosystems. However, many moths visit flowers to obtain pollen or nectar as food— with sufficient nectar supply a critical resource for the insects—and do not necessarily pollinate them. Many observations of visits to flowers have not confirmed the dependence of those flowers on the moths for pollination, but flower visitation and the presence of pollen on the visiting moth are often taken as a valid proxy for ‘pollination’, even when pollination was not proven conclusively. Using this approach across a broad literature review, Macgregor et al. found accounts of representatives of 75 plant families pollinated partially or exclusively by moths. Some studies implied that moths were second in importance only to bees in the provision of pollination services. The survey also revealed that comparative values of moths over some other pollinators could occur for plants that are not pollinatorspecific. In particular contexts, listed benefits from moths included (1) greater gene flow between populations, shown by movements of genetic markers in experimental populations; (2) longer distance dispersal of dye-marked pollen; (3) ‘higher quality pollination’, namely equal or greater seed set from the transfer of less pollen; and (4) more efficient pollination, with a lower ratio of pollen removed to pollen transferred from a single visit. They also remarked the two ‘pollination syndromes’ distinguished earlier (Willmer 2011) as (1) ‘sphingophily’, pollination by hovering hawk moths, and (2) ‘phalaenophily’, pollination by settled moths of other families, and confirmed that the studies they reviewed included many examples of both categories. Many such examples have considerable importance to the species directly involved and their host communities. Approaches to assessing the importance of moths as pollinators in New Zealand (Buxton et al. 2018) emphasised the need for experimental studies rather than relying on observational records of flower visits by moths. They highlighted that—as for Australia—lack of detailed information largely precluded defining moth importance and that many reported observations were indeed simply of floral visitations by moths whose identity was unknown and which are not themselves proof of pollination occurring. Drawing from wider records, Buxton et al. noted eight categories of ‘evidence’ for moth pollination, of which only the last two in Table 2.1 are conclusive.

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Inferences on the importance of moth pollination may be strong. New Zealand’s Sub-Antarctic Islands, for example, support a number of apparently insect-pollinated flora but no bees or butterflies so moths and flies are the most apparent potential pollinators. A short survey on Enderby Island (Auckland Islands archipelago) demonstrated that moths (six species and a total of 241 individuals examined for pollen grains on their bodies) could carry pollen, collectively of four plant species (Buxton et al. 2019) and be active even under extreme weather conditions that more generally do not suit flying insects. Pollen was found only on the most abundant moth, Graphania erebia, endemic to the archipelago and the only resident noctuid. In severe weather, it crawls on the flowers and so avoids flight whilst maintaining close contact with potential pollen sources. Pollen grains were found on 19 of the 231 specimens of this predominant species, which was regarded as a generalist. Although that survey did not provide definitive evidence of moth pollination, Buxton et al. (2019) noted the likelihood that this indeed occurred and that the loss of such generalist species in depauperate environments may be functionally significant. A literature survey of putative moth pollination, emphasising records from North America and Europe (Hahn and Bruhl 2016), identified Sphingidae and Noctuidae as the predominant families reported, whilst many other families participated to lesser extents. It appeared that the roles of moths as pollinators were likely to have been considerably underestimated, because the number of studies traced was rather small. Additional examples of pollination specificity involving moths are certain to be revealed, perhaps especially amidst the least studied groups. The importance of the numerous tiny Heliozelidae as pollinators of endemic Boronia spp. and other native flora in Australia, for example, is only now becoming apparent (p. 81); many species seem to be highly host-specific. The family is proving to be remarkably rich, with its major divisions each associated primarily with a particular plant group. The intricate and often obligate interactions between some ‘nursery pollinators’ and their host plants are mutualisms from which both participants benefit. This term applies to moths that are specific pollinators and oviposit in flowers so that larvae then feed on the developing seeds. Many are indeed obligate, but some interactions are rather more flexible, and bees or other alternative pollinators are known. Some key cases have been studied in considerable detail to determine the extent of the mutualism or whether the interaction may be more antagonistic as for the more usual image of herbivore–plant interactions (see New 2017). Yucca plants (Agavaceae) are pollinated only by yucca moths (Tegeticula, Parategeticula, Prodoxidae). The female moths lay few eggs and caterpillars do not eat most of the developing seeds, so the survival rate is high (Pellmyr 2003). Senita moths (Upiga virescens, Crambidae) are obligate pollinators of Senita cactus (Lophocereus schottii), which can also be pollinated by bees. Moth pollination is the more efficient (Holland and Fleming 2002), and, again, seed consumption by caterpillars is rather low. In contrast, Silene spp. and related Caryophyllaceae can be pollinated by either Hadena spp. (Noctuidae) or Perizoma spp. (Geometridae), and seed predation can range from 0 to 100%, with this interaction ranging from mutualism to parasitism (Kephart et al. 2006).

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Synchronisation of the life history of a nursery pollinator with that of its obligate host plant is critical to sustaining the mutualistic relationship. The possible mechanisms have been explored for an Australian case involving native Phyllanthaceae and species of mutualist Epicephala moths (Gracillariidae), specifically the relationship between Breynia oblongifolia (found along the east coast) and two associated species of Epicephala—neither of which could be named with confidence (Finch et al. 2021). More broadly, it is believed that up to 700 species of Phyllanthaceae depend on pollination by this genus of ‘leaf flower moths’. The moths appear to use diapause at different stages of the life history to adjust to variable flowering phenology; diapause as eggs or young larvae within pollinated flowers enables adults to appear as the flowers mature, but some individuals may undergo a protracted prepupal diapause and emerge a year later.

2.4

Variety in Feeding and Resources

The most familiar scenario of a moth life history is of relatively sedentary free-living larvae feeding on plants (especially foliage) and more mobile adults feeding on nectar or not feeding at all. This basic ‘stereotype pattern’ applies to the vast majority of Lepidoptera but, as for any such large and diverse insect group, exceptions occur and are salutary reminders that overgeneralisations about either adult or larval feeding habits may be misleading. Perhaps the most familiar exceptions are the ‘clothes moths’ (some Tineidae), larvae of which feed on keratin-based animal products such as wool, fur or feathers. Some are domestic or economic pests through their depredations of such stored materials. Many moth larvae are found in bird nests, and it is often unclear whether they are feeding on nest material or nestling faeces. However, some other moths have specialised relationships with other animals, with larvae being obligate parasites or predators. Most of these belong to rather small moth groups, and the examples below illustrate their idiosyncrasies and variety. 1. The small family Epipyropidae is concentrated in the Oriental/Australasian region, with five of the 40 or so species native to Australia. Larvae are ectoparasites of Homoptera—either lantern bugs (Fulgoridae) or cicadas—and attach to the host abdomen in order to feed on abdominal contents after penetrating the cuticle. Fully grown larvae leave the bug and spin cocoons on the bark of the tree occupied by the host. Adult moths are short-lived and do not feed; some may be parthenogenetic (Liu et al. 2018), but it is still unknown how they locate their hosts. 2. Some moths are specialised predators on Homoptera, larvae of some living beneath colonial scale insects on which they feed. The pyralid Laetilia coccidivora is an important predator of the scale insect Dactylopius opuntiae, a major pest on prickly pears grown for fruit in Mexico (Cruz-Rodriguez et al.

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3.

4.

5.

6.

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2016). In Australia, larvae of the small endemic family Cyclotornidae feed on Homoptera and early stages of ants. A well-publicised example of larval predation by Lepidoptera is for most species of endemic Eupithecia (Geometridae) in the Hawaiian archipelago, in which Montgomery (1982, 1983) described the elaborate ambush behaviour by which cryptic larvae of all but two species actively capture and devour a variety of small insect and other arthropods. Later workers (notably Mironov 2014) noted that they are indeed generalist feeders that capture any prey that come into range. Eupithecia is one of the richest and most widely distributed genera of Geometridae, with about 1500 described species, but this behaviour has apparently developed only in Hawaii. However, more casual ingestion of small arthropods encountered on food plants is more widespread, and cannibalism has also been recorded and may be a precursor to the development of more defined predation (Mironov 2014). Eupithecia itself does not occur in Australia, but closely related members of the tribe Eupitheciini are well represented. A notable second example from Hawaii involves the large endemic genus Hyposmocoma (Cosmopterigidae) that contains more than 400 species (‘a third of all Hawaiian lepidopteran diversity’: Haines et al. 2014), many of them very narrowly distributed and found only on single islands. Hyposmocoma is found widely in forests and on many different plants, but some species have become predators of terrestrial snails (Rubinoff and Haines 2005). The specialised Hyposmocoma molluscivora discussed by Rubinoff and Haines uses silk to capture and immobilise snails (Tornatellides spp.) by attaching the shell to the substrate and enabling the case-bearing caterpillar to feed on the snail within its shell. Many butterflies, especially within Lycaenidae, are myrmecophilous, with larvae having intricate (and often very specific and obligate) relationships with ants. Larvae then feed on ant brood or, in some taxa, have a ‘cuckoo’ lifestyle, whereby they encourage regurgitation (trophallaxis) from ants and also eat trophic eggs. This habit is apparently very rare in moths, but Dejean et al. (2016) reported that larvae of an African moth (Eublemma albifascia, Erebidae) exploit the weaver ant Oecophylla longinoda in this way. Both Eublemma and this ant’s closest relative, the Green tree ant, Oecophylla smaragdina, occur in Australia, but this unusual habit has not yet been reported. Adult feeding on liquids other than plant nectar or juices (such as from ripe fruit) is rare, but some moths have been recorded feeding on animal pus or tears. In a few extreme cases (Calyptra, Erebidae), moths have a barbed proboscis enabling them to pierce the skin and suck fresh mammalian blood (Banziger 1968, 2021).

Intricacies of some other cases remain unresolved. The larvae of the species of Trisyntopa (Oecophoridae) feed on faeces of Psephotus parrot chicks within termite mounds (p. 165), and it is uncertain whether this is a ‘one-way’ association of caterpillars gaining an unusual specific resource or whether there is some more tangible mutualistic relationship (Cooney et al. 2009).

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All these variations, together with the different patterns of herbivory, confirm the ecological variety within Lepidoptera and the need for detailed biological information in assessing if and how conservation is to be pursued. Ecological flexibility is displayed by Hyposmocoma (above) in another intriguing way—some species from the high mountains of Hawaii have become truly amphibious and can persist in either aquatic or terrestrial environments indefinitely (Rubinoff and Schmitz 2010). Their aquatic habit has apparently arisen independently in several clades with different larval case structures, and the invasion of remote Hawaiian streams may perhaps have been facilitated by the lack of many aquatic insect groups in the archipelago. The high mountains there are regarded as amongst the ‘wettest places on Earth’ (Rubinoff and Schmitz). Each aquatic moth species occurs only on a specific volcano, where each is highly restricted and progressively vulnerable as water is diverted for human use. A few groups of moths have become more widely aquatic through feeding on aquatic plants: Pabis (2018) noted that truly aquatic moths occurred mostly in Crambidae, but with representatives also in Cosmopterigidae and Erebidae, whilst ‘semi-aquatic’ moths associated with marsh or amphibious plants included species of about a dozen families, for an overall total of around 800 species in these categories. The biology and ecology of most are not well known, but many appear to have rather limited geographical distributions. These species have not yet attracted much conservation attention. The distribution of any moth species is determined by the availability of its key resources and its environmental tolerances. Both essentially lead to many species showing a ‘gradient’ of incidence or abundance in relation to resource supply, climate and the influences of co-occurring taxa. Studies of moths along ecological gradients—whether natural (such as elevation or latitude) or imposed (such as transitions between natural areas and urban, forestry or agricultural developments) have received considerable attention in understanding patterns of incidence and diversity and the factors that influence these. A common finding, not confined to moths, is that intensity of disturbance can be related to the level of ‘biotic homogenisation’, with the simplified landscape of intensive agriculture (for example) leading to loss of habitat specialists and poorly dispersing species (Ekroos et al. 2010). Disturbance gradients in habitat conditions are thus a widespread concern, but the ‘stages’ may be varied and difficult to define fully, beyond the most obvious conditions. The three disturbance classes compared for Sphingidae in south-east Asia (Beck et al. 2006, p. 16), for example, were (1) primary habitats without any significant human disturbance; (2) secondary habitats, including areas that had been selectively logged, were secondary rainforest or otherwise showing signs of moderate interference; and (3) heavily disturbed habitats, largely anthropogenically opened landscapes. More precise conditions were very varied and in some cases these could not be defined fully, but this difference alone revealed likely differences in the spectrum of hawk moth species present, even amongst the incompletely defined fauna of Borneo. Not all such gradients are initially obvious. Thus, the synthesis of studies of moth diversity related to vertical stratification between the understorey and canopy of

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Fig 2.1 Species richness (measured by Fisher’s alpha) of Geometridae in habitat gradients in Borneo. Light—trapping sites along two gradients of habitat change (1, forest to 6, cultivation: Serinsim, sites 1–6; Poring, sites 1–6) are summarised, with ground-level (solid circles) and canopy (open circles) richness shown (after Beck et al. 2002)

tropical and subtropical forests (Ashton et al. 2016a) illustrated considerable differences, and some related studies have shown differences for particular taxa. In the Costa Rica rainforest, for example, Brehm et al. (2007) found that assemblages of tiger moths (Erebidae: Arctiinae) and Geometridae differed between understorey and canopy, with Arctiinae more prevalent in the canopy and Geometridae in the understorey. Surveys of ‘forest moths’ for assessment of diversity may thus need to consider such strata carefully and sample each separately. Distribution of food plants, nectar and fruit supply (the last evident especially from several studies on fruit-feeding butterflies) and impacts of natural enemies may all influence such vertical distributions, as an aspect of wider disturbance gradients. Trends were exemplified by the transition from primary forest to cultivated farmland in Borneo, with the latter condition also providing opportunities for the study of successional effects as abandoned areas proceed towards the secondary forest. Again for Geometridae, assemblages became impoverished with increasing disturbance, and this trend was postulated to have at least three suites of causes (Beck et al. 2002), as (1) changes in microclimate conditions due to disturbance, reflected in gap creation and changes in stratification, allowing possible increased incidence of canopy species at ground level, but also losses of shade-adapted taxa; (2) population control by natural enemies may be stronger in structurally complex vegetation and might suppress dominance by a few species and facilitate survival of less competitive ‘rare’ species; and (3) availability of resources may change due to alterations in vegetation along habitat gradients (Fig. 2.1).

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Simplistically, and perhaps obviously, a specialist herbivore cannot persist in places where its food plants do not occur, whilst the presence of those food plants does not guarantee the coexistence of the herbivore, whose presence may be restricted by climate or other influences rather than by food alone. The presence of a specialist moth in places where known larval food plants do not occur may reflect (1) that the moth is a non-breeding ‘tourist’ present fortuitously; (2) that the food plant is present in small numbers and has not yet been found; or (3) as very common, that the full food plant range of the moth is unknown. ‘Shallow ecological gradients’ such as small changes in the floristic composition may influence moth community patterns (Uhl et al. 2021), as may the transient appearance of particular plant species following management or during succession (Jonason et al. 2013). However, far more attention has been paid to differences and changes along elevational and latitudinal gradients, rather than stratified distributions within a vegetation system, and in some cases, these mirror trends anticipated as climate changes occur (p. 89). Elevational gradients are attractive for study, because they include strong gradients within short distances and the local species pool of target taxa can be defined well. Elevational stratification of moths occurred along three forested montane transects in China, on all of which sampling at 200 m height intervals showed significant changes in assemblage composition (Ashton et al. 2016b), as a trend also evident in Australia (Ashton et al. 2016c). Ashton et al. noted that a 200 m vertical interval represented about 1.5 °C change in average temperature, a figure less than several published estimates for climate change over the next few decades. Surveys along an elevational rainforest transect in Eungella, Queensland, in November (13,861 moth individuals, ca 713 morphospecies) and March (10,045 individuals, ca 607 morphospecies) showed distinct lowland and upland moth assemblages in both seasons (Odell et al. 2016), in part reflecting the forest stratification and its transition from lower-level mesophyll forest to notophyll vine forest at higher elevations together with shifts in climate, notably temperature. The vertical zones of the canopy and understorey also support different moth assemblages, so that either can include a valid indicator or ‘predictor’ species of the conditions at a particular elevation (Nakamura et al. 2016). The diversity of geometrid moths in Borneo showed a clear peak at mid-elevations (Beck and Chey 2008), whilst some other surveys have implied little change or sharp declines at higher elevations. Interpreting any such trends involves a number of different components, but temperature and plant diversity are perhaps the most direct influences on any local moth assemblage. Mid-elevational peaks in abundance, assessed mainly from the richness of diverse families (notably Geometridae), are sometimes linked with disturbances at lower levels to leave more pristine forests at those higher elevations, with climatic changes reducing richness at higher levels. An overview of 26 elevational gradient surveys of Geometridae from many parts of the world (Beck et al. 2017) revealed many to have a mid-elevational peak of richness, irrespective of climate and geographical location, with convincing explanations of this so far elusive. The richness of Geometridae from different forests in Papua New Guinea (Paliau et al. 2022) and Borneo (Beck and Vun Khen 2007) differed with elevation and extent of habitat

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Fig 2.2 Numbers of species of Geometridae per trap in different forest types in Papua New Guinea: lowland and lower montane forests were each sampled in primary and disturbed (degraded and/or logged) locations. Numbers based on a pool of 1108 morphospecies (total of 11,830 specimens) taken over a total of 152 trap nights (4 nights/site) across sites throughout six provinces; forest categories are LFD (lowland forest disturbed), LFP (lowland forest primary), LMD (lower montane forest disturbed) and LMP (lower montane forest primary) (redrawn from Paliau et al. 2022)

disturbance, as well as differences in weather and in sampling in relation to flight activity. Although Geometridae were present at all elevations sampled, Paliau et al. noted that some species occurred at only one elevation whilst others occurred throughout the gradient examined. A mid-elevational peak at 1400–1600 m was accompanied by a decrease at higher sites, especially those above 2500 m. However, the richness in the disturbed forest was substantially greater than in the primary forest (Fig. 2.2). The meldings of ecological features of moths with the gradients of environmental conditions to which they respond are reflected in the suites of life history traits (LHTs) they display. LHTs have evolved in response to environmental conditions, give many species a characteristic ecological profile and dictate that responses to environmental change may be reflected directly by the presence or richness of species and their relative representation and abundance. The LHTs may constitute or be reflected in gradients, as discussed by Potocky et al. (2018) for a suite of 1124 moth species from central Europe, based on the traits summarised in Table 2.2. Many LHTs are equivalent to characteristics of ‘more generalist’ and ‘more specialist’ species. Ordinations of LHTs for the moths revealed some clear trends. For voltinism, highly dispersive and polyphagous species can track resources over wide scales and are more unlikely to decline. Obligate univoltine species with short-flight seasons in

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Table 2.2 Suite of life history traits used to appraise and compare ecological gradients and related to distribution and rarity/vulnerability of moths in central Europe (Potocky et al. 2018): 27 traits were distinguished and ranked in 44 trait states Trait group States Traits related to mobility, voltinism and related themes Wingspan, as a possible proxy for dis- Numerical variable persal ability and host plant use Overwintering stage Ordinal value from egg (1) to adult (4) Voltinism Mean number of generations/year Semivoltine (>1 year) Score 1 (present), 0 (absent) Migrations Score 0 (present), 1 (absent) Flightless (female wings reduced) Score 0 (present), 1 (absent) Traits related to duration and timing of the adult stage Flight period Five states factor (early spring, spring, summer, autumn, winter) Flight period length Numerical variable as the sum of above flight periods Traits related to larval feeding Trophic range Numerical scale to define scale of monophagy, oligophagy and polyphagy Host plant form Includes apparency and plant defences; ordinal scale for forbs (1), through grasses, shrubs, trees to non-vascular plants (5) Host plant part Defines larval feeding ‘window’; three states as flowers/seeds, leaves, stems/roots Larval carnivory Including opportunism, modifying effects of plant nutrition quality Detritivory Feeding on dead/decaying plant material Traits related to larval defences Larval sociality Assumed defensive function; ordinal with three conditions: solitary, small groups, large aggregations Hairy larvae Covering whole body; score 0 (present), 1 (absent) Adult resources, defences or crypsis Adult feeding Score 0 (present), 0 (absent) Adult activity Distinguishes nocturnal and diurnal activity; score 0/1 or 0.5/0.5 if both present Sexual dimorphism in adults Score 0 (present), 1 (absent) Seasonal polyphenism in adults Score 0 (present), 1 (absent) Habitat use (in Central Europe) Altitude range Numeric, as lowlands (1, 250 to 1000 m asl) Habitat range Number of habitat types; 12 categories listed, translated into ranked variables as the following four traits, each with three states Habitat 3D structure Habitat temperature Habitat humidity Habitat acidity (continued)

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Table 2.2 (continued) Trait group Species range Range size Range type

States Global range: four categories ranked from ‘1’ (small) to ‘4’ (‘huge’) Eleven state factors, with entities such as Mediterranean, Pantropical and Palaearctic, to summarise geographical restrictions/distribution

Fig 2.3 (a) Extinction risk and (b) distributional range changes of Geometridae in Finland in relation to body size and dietary breadth (solid line, oligophagous species; dotted line, polyphagous species; dashed line, monophagous species) (Mattila et al. 2008)

early spring or late autumn can also be associated with very abundant resources such as foliage of deciduous trees. High generation number and long adult flight periods augment broad diets in promoting resistance to changes. Ecological features and traits of moths can thus contribute to the assessment of extinction risk. Several such traits were examined in relation to changes in distribution and extinction risk for 284 resident species of Geometridae in Finland (of which 31 species were designated ‘threatened’ and 253 ‘unthreatened’). Over two series of records (before 1988 and 1988–1997), distribution declined by 21.5%, with the greatest declines amongst threatened species (Mattila et al. 2006, 2008). Distributional and extinction risk changes in relation to diet breadth, as a central ecological correlate, are shown in Fig. 2.3. In addition to diet breadth, the distinction of larval feeding guilds and their relative representation can be useful indicators of management effort. For moths of

References

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managed conifer forest in Germany, Thorn et al. (2015) recognised six different feeding guilds, namely species depending on trees and shrubs (188 species), herbs and grasses (140), omnivores (67), saproxylic feeders (19), detritus feeders (10) and moss feeders (4). The guilds were sensitive to silvicultural management and to postdisturbance management. As one example, the responses of saproxylic/detritus feeders and moss feeders differed between multi-layered and single-layered forests, implying that both categories of stands are needed to conserve moth functional diversity across the landscape. Relative representations and changes amongst feeding guilds may become informative tools for assessing environmental impacts.

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Kuhn JG, Austin JJ, Reardon TB, Prowse TAA (2022) Diverse moth prey identified in the diet of the critically endangered southern bent-wing bat (Miniopterus orianae bassanii) using DNA metabarcoding of scats. Wildlife Res. https://doi.org/10.1071/WR21052 Liu Y, Yang Z, Yu Q, Wei C (2018) Cicada parasitic moths from China (Lepidoptera: Epipyropidae), morphology, relationships, biology and biogeography. Syst Biol 16(4). https:// doi.org/10.1080/14772000.2018.1431319 Macgregor CJ, Pocock MJO, Fox R, Evans DM (2015) Pollination by nocturnal Lepidoptera, and the effects of light pollution: a review. Ecol Entomol 40:187–198 Mattila N, Kaitala V, Komonen A, Kotiaho JS, Paivinen J (2006) Ecological determinants of distribution decline and risk of extinction in moths. Conserv Biol 20:1161–1168 Mattila N, Kotiaho JS, Kaitala V, Komonen A (2008) The use of ecological traits in extinction risk assessments: a case study on geometrid moths. Biol Conserv 141:2322–2328 Mironov VG (2014) Geometrid moths of the genus Eupithecia Curtis, 1825 (Lepidoptera, Geometridae): prerequisites and characteristic features of high species diversity. Entomol Rev 94:105–127 Montgomery SL (1982) Biogeography of the moth genus Eupithecia in Oceania and the evolution of ambush predation in Hawaiian caterpillars (Lepidoptera: Geometridae). Ent Gen 8:27–34 Montgomery SL (1983) Carnivorous caterpillars: the behavior, biogeography and conservation of Eupithecia (Lepidoptera: Geometridae) in the Hawaiian Islands. GeoJournal 7:549–556 Nakamura A, Burwell CJ, Ashton LA, Laidlaw MJ, Katabuchi M, Kitching RL (2016) Identifying indicator species of elevation: comparing the utility of woody plants, ants and moths for longterm monitoring. Austral Ecol 41:179–188. https://doi.org/10.1111/aec.12291 New TR (2017) Mutualisms and insect conservation. Springer, Cham Odell EH, Ashton LA, Kitching RL (2016) Elevation and moths in a central eastern Queensland rainforest. Austral Ecol 41:133–144. https://doi.org/10.1111/aec.12272 Pabis K (2018) What is a moth doing under water? Ecology of aquatic and semi-aquatic Lepidoptera. Knowl Manag Aquat Ecosyst 419:42. https://doi.org/10.1051/kmae/2018030 Paliau J, Mani A, Napa L, Uvau C, Sau S et al (2022) Geometrid moth richness, distribution and community composition in different forest types of Papua New Guinea. Case Studies Environ:1–12. https://doi.org/10.1525/cse.2022.1474225 Pellmyr O (2003) Yuccas, yucca moths, and coevolution: a review. Ann Miss Bot Gdn 90:35–55. https://doi.org/10.2307/298524 Potocky P, Bartonova A, Benes J, Zapletal M, Konvicka M (2018) Life-history traits of Central European moths: gradients of variation and their association with rarity and threats. Insect Conserv Divers 11:493–505 Rubinoff D, Haines WP (2005) Web-spinning caterpillar stalks snails. Science 309:575 Rubinoff D, Schmitz P (2010) Multiple aquatic invasions by an endemic, terrestrial Hawaiian moth radiation. Proc Nat Acad Sci 1079130:5903–5906 Thorn S, Hacker HH, Seibold S, Jehl H, Bassler C, Muller J (2015) Guild-specific responses of forest Lepidoptera highlight conservation-oriented forest management – implications from conifer-dominated forests. For Ecol Manage 337:41–47 Uhl B, Wolfling M, Fiedler K (2021) Exploring the power of moth samples to reveal community patterns along shallow ecological gradients. Ecol Entomol 47:371–381. https://doi.org/10.1111/ een.13122 Willmer P (2011) Pollination and floral ecology. Princeton University Press, Princeton

Chapter 3

Moth Declines and the Need for Conservation

3.1

Introduction

In addition to the fate of individual species, the considerable concerns over the declines of moths apply to the three main parameters of richness, abundance and distribution, for all of which evidence has its foundations in the extensive documentation and historical record of larger moths in the northern temperate regions, most notably in the United Kingdom flowing from surveys initiated in 1933 as the Rothamsted Insect Survey. These extensive long-term light-trap samples that cover the entire flight periods of most species have enabled sound interpretation of trends in diversity and the fate of numerous individual species. Without such long-term monitoring data, trends in insect population sizes (which may vary greatly, irregularly and rapidly about a long-term mean abundance) are highly uncertain. Concerns have arisen also from collector experiences—for the north-eastern United States, moth declines have been a concern for well over half a century, and Wagner (2012) cited the observations of enthusiasts who had observed larger moths over several decades, during which a number of Saturniidae and Sphingidae had declined or been extirpated. Thus, of Connecticut’s 35 resident or previously resident hawk moth species, two have been extirpated, a third are considered likely to have gone and 14 others have declined—some of them are apparently close to being lost. Several previously abundant species had become ‘noticeably less abundant’. Many changes in circumstances can lead to insect population declines and increase the risk of their extinction. For herbivores, such as most moths, the impacts of host plants on population fitness and size are clearly important, but, despite the considerable debate, the relative vulnerabilities from this and features of the moths themselves (such as dietary breadth) are often unclear. Many moth species are rarely encountered, leading to suspicions of extinction that cannot be proven definitively and with underlying causes of scarcity or loss usually unclear. As Nieminen (1996) put it, ‘There are typically many potential and possibly interrelated causes of extinction which may be nearly impossible to uncover even experimentally’. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2023 T. R. New, The Other Lepidoptera: Moth Conservation in Australia, https://doi.org/10.1007/978-3-031-32103-0_3

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Table 3.1 Problems of detecting and understanding the causes of insect population extinctions (after Niemenen 1996) 1. It is usually difficult to be certain that extinction has actually occurred: rare or low-abundance insects are often difficult to detect, especially without extended surveys 2. Even if a local extinction can be confirmed, it is difficult to determine the factors that have been responsible for the loss; many factors may be involved and may interact in various ways 3. Those factors probably vary in time and space, with their relative significance also varying 4. The critical factors may differ from one species to another 5. The risk of population extinction may be so small that during any single study only a few observations of extinction can be accumulated

Summarising why population extinctions are hard to investigate (Table 3.1) helps to define the natural parameters against which impacts of anthropogenic threats may be assessed. Nevertheless, Nieminen’s discussion (based on moth occupancy of islands of a series of sizes comprising an archipelago in southern Finland) suggested not only that the larger populations on larger islands (as a reflection of habitat area) are more resilient to loss than small populations, especially those on small islands, but also that some vegetation trends are correlated with extinction risk. With increasing island area, extinction risk decreased faster amongst perennial-feeding than annual-feeding species, possibly because perennial plants provide a more predictable and stable resource. Similarly, coniferous trees provide a more predictable food supply than deciduous trees. Implicit in these trends, habitat specialists with limited food supply may become extinction-prone, not least—as MacArthur pointed out long ago (MacArthur 1955)—because no alternative host plants are available to buffer the decline of the single host.

3.2

Detecting and Assessing Species Declines

Species extinctions—or more local losses, extirpations—can thus easily pass unnoticed other than in the most intensively investigated areas such as Britain, or where recent losses can be placed in a historical context, or attributed directly to recent changes. More moths have been declared extinct from the Hawaiian archipelago than any other part of the world, with (1) classical biological control agents imported to counter agricultural pests and (2) habitat losses both implicated repeatedly. Those losses include large and conspicuous species. The Kona giant looper (Scotorythia megaphylla, Geometridae) was the second largest moth on the archipelago, second only to Blackburn’s sphinx (Manduca blackburni, Sphingidae), also believed for some years to be extinct but now ranked as ‘endangered’ following the discovery of several populations (p. 105). Elsewhere, losses are more often inferred, but with an enduring hope that the moth may be rediscovered through fuller exploration, as occurred recently for an ancient moth lineage in Australia. The Kauri moth, Agathiphaga queenslandensis

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(Agathiphagidae), is associated with old kauri pines, which have been logged extensively in the past for timber. Larvae feed in the fallen seeds and can undergo very long diapause, noted as 12 years by Upton (1997). Known from few specimens, and one of only two species then known in the family, the moth was believed widely to be extinct. It had not been seen for more than 40 years before its recent rediscovery by direct retrieval of larvae from examination of fallen Araucaria seeds (by DPA Sands, as reported in news bulletins on 25 July 2019: Sands pers. comm.: DNA identity confirmed by Andreas Zwick, CSIRO). However, for some other species, persistent searches by experienced lepidopterists over many years have failed to rediscover the target. The New Zealand geometrid Xanthorrhoea bulbata was once considered common on grasslands, but has not been seen since 2000, following records of only two individuals since World War II (Patrick 2000; Hoare et al. 2017). As Hoare noted, nothing is known of the biology of this endemic species, and reasons for loss (or extreme scarcity) can only be conjectured. That situation occurs widely. One of the more fully investigated species in New Zealand, the geometrid Asaphodes frivola (the Remuremu looper), represents an endemic genus with around 50 species, some of which have declined considerably (Patrick 2000). In the far south of the South Island, seven of the 11 Asaphodes species near Invercargill have become rare or locally extinct, from causes such as land clearing for urbanisation and associated infrastructure such as roads and pylons, with wetlands also severely affected since the late 1850s. A. frivola is sexually dimorphic, with short-winged flightless females (p. 92) and is endemic to a small stretch of coastline near Invercargill. At its ‘best’ site, Patrick (2014) noted the apparent area of occupancy at less than 25 m2, with the high risk of habitat loss from increased use of a local road and boat ramp, as well as from fire and weed invasion. Only two populations were then known, with surveys failing to discover any further incidence. Patrick (2014) regarded A. frivola as ‘perilously close to extinction’, and it has been ranked as ‘Nationally Critical’, a status shared by 25 of the 66 threatened New Zealand Lepidoptera listed by Hoare et al. (2017). The vulnerability associated with small distribution is illustrated well by the Sandhill rustic moth (Luperina nickerlii leechi, Noctuidae) in southern England, where it occupies a total range of only about 0.5–1.5 ha within a habitable area of about 300 × 25 m in which the sole larval food plant (Sand couch grass, Elytrigia juncea) grows. This isolated population—some 300 km from that of its closest relative—is inherently vulnerable, as the shingle beach (Loe Bar, Cornwall) is affected by storm damage and human intrusions (Spalding 2015). The adult moth is able to resist tidal cycles through its highly unusual behaviour of moving into seawater at high tides and clinging to submerged grass stems. As Spalding discussed, the moth is a high conservation priority, not least because of the inherent likelihood of sea-level rise submerging the entire habitat, but also from stochastic events such as storm damage that render outcomes of any long-term conservation planning very uncertain. Some historical records of moths present a continuing challenge for rediscovery and clarification of their status. Some are also of considerable taxonomic interest. In

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New Zealand, the Frosted phoenix, Titanomis sisyrota (family uncertain), has been designated ‘New Zealand’s most enigmatic moth’ (Hoare 2001); it is known from no more than 10 specimens captured at intervals from 1874 to 1959, since when it has not been seen—despite substantial search effort. At about 6 cm wingspan, it is perhaps likely to be noticed. It remains uncertain whether it is extinct or simply extremely rare and elusive. Hoare believed that allocating it as ‘extinct’ may be premature and suggested steps for an energetic publicity campaign in the hope of rediscovering the moth. Another New Zealand moth, perhaps even more difficult to appraise, is one of the country’s largest swift moths (Aoraia [or Porina] mairi, Hepialidae, about 15 cm in wingspan). It is known from a single specimen captured in 1867 and necessarily treated as ‘species incertae sedis’ by Dugdale (1994) who noted it as an ‘enigmatic behemoth’. As of February 2022, no further information has been obtained on either of these species (Robert Hoare, pers. comm.). Perhaps the most spectacular extinct moth is the large and brilliantly coloured Sloane’s Urania (Urania sloanus, Uraniidae) endemic to Jamaica, where it became extinct around the end of the nineteenth century—probably in 1894 or 1895 but possibly as late as 1908. Declines in lowland rainforest as conversions to agricultural land increased were likely to have incorporated losses of larval food plants (treelike Euphorbiaceae), and consequently increased exposure to hurricanes may have hastened the decline (Nazari et al. 2016). However, much apparently suitable forest was present much later (Lees and Smith 1991), and the reported food plant (Omphalea triandra) remained widespread. U. sloanus apparently shared the features of some of its relatives, of exploiting different food plant species in different areas and undergoing strong periodic adult migrations between separate hosts. The Madagascan Chrysiridia rhipheus, for example, migrates between four different Omphalea species in such alternating food plant dependence (Lees and Smith 1991). Such patterns may link with the toxic contents of the different food plants (Smith 1983), but raise the possibility that declines of either food plant in Jamaica may have contributed to the loss of U. sloanus. The ‘classic’ case of putative moth extinction of the Levuana (or Fijian coconut) moth, Levuana iridescens (Zygaenidae), in the 1930s has been cited repeatedly as a highly successful classical biological control campaign (p. 101). The tachinid fly parasitoid Bessa remota was introduced to Fiji from Malaysia in 1925, and the moth, a major pest of coconut plantations, declined rapidly. It was last seen in 1956 and declared extinct by IUCN in 1996. Levuana was for long considered to be endemic to Fiji, but this has been debated extensively, and it may be an arrival from further west (Hoddle 2006). Likewise, its extinction has also been doubted (Kuris 2003), with suggestions that refugial populations may persist on other small remote and inaccessible islands and using different palm host plants, possibly also as islands on which coconuts are not cultivated commercially (Nazari et al. 2019). Uncertainties of interpreting even such widely claimed losses remain. Very broadly, investigations of moths for conservation embrace the themes of (1) detecting focal species, perhaps across a variety of potential habitat patches; (2) assessing the abundance and distribution of such species, the threats to them and the patterns and extent of change; (3) evaluating diversity, most frequently as the

3.3

Changes in Moth Assemblages

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number of species, either wholly or of particular selected families; and (4) comparing species richness and species incidence across places and times, either as single incidence inventories or in relation to habitat condition and change.

3.3

Changes in Moth Assemblages

Changes in moth assemblages are cited commonly as species richness, abundance of particular taxa, relative abundance and representation of some form of designated ‘functional groups’ and the loss or advent of taxa. The last of these, ‘species replacement’, is frequent and confounds simplistic interpretations of species richness—in which, for example, the number of moth species in small forest patches is sometimes broadly similar to that in large forest areas. In both temperate and tropical forests, this may infer that habitat loss or fragmentation has little impact. However, as Summerville (2004) discussed, the composition of that richness may have changed substantially, so that (1) fewer of the species in smaller patches are dependent on interior forest habitat and (2) a greater number of ‘edge-tolerant’ species occur there. Thus, although richness seems similar, functional composition by replacement may involve numerous species. Such changes in forests towards species with larvae feeding on herbaceous vegetation are more clearly evident than the parallel—but less marked—changes occurring along many successional gradients, in which moth species from different feeding guilds (or other functional groups) replace each other along gradients of subtle habitat change. Detection of such replacements usefully involves a fuller approach to defining functional groups than the commonly used basic ‘specialist–generalist continuum’. Summerville and Crist (2003), for example, distinguished five trophic groups of forest moths for ecological categorisation of the fauna, as woody plant feeders, herbaceous feeders, dead/dying vegetation feeders, encrusting plant feeders and generalised feeders that transcend two or more of these. Recognition of these could help to inform relationships between moth community change and forest architecture after habitat loss, detecting species replacement but also clarifying the particular assemblages across which functional replacement occurs (Summerville 2004). It is sometimes possible, and more universally desirable, to monitor the condition of sites on which the single or few presumably remnant population(s) of rare moths occur, in order to hone any conservation management by increasingly sound ecological information. The last-known English population of the Dark bordered beauty moth, Epione vespertaria (Geometridae), was monitored, together with the density of its sole host plant, Salix repens (Salicaceae), to show a substantial decline in moth density and distribution, as well as greatly reduced host plant density and size over 2007–2014 (Baker et al. 2016). The rapid decline of the moth population appeared likely to be driven by changes in the Salix population—with fire and changes from frost and grazing contributing to this. Baker et al. noted the general need to monitor such priority insect species, not least in order to resolve any ‘conflict’ between broader management for the habitat and the detailed needs of the species itself.

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Other than focusing on single species, changes in moth abundance and in the richness and composition of moth assemblages are the widest basis for conservation concern. Many moths have strong and reasonably definable phenology with adults present for only part of the year. Their incidence can be appraised only from longterm or sufficient interval samples to assess faunal turnover in time, but in seeking any particular species at even slightly different times of year sampling may give spurious inferences on residency and on the composition of assemblages. Thus, Highland et al. (2013) grouped Oregon moth assemblages into 2-week sampling periods and showed that species turnover at biweekly or monthly intervals was higher than spatial turnover between nearby different habitat types. Strong seasonal patterns can occur: in eastern North American forests species turnover between early and late seasons at a site was greater than spatial turnover between separated forest patches (Summerville and Crist 2003). Both temporal and spatial turnovers contribute to overall faunal diversity. However, whilst the seasonal appearance of adult moths is well-defined for many temperate region taxa, far fewer critical appraisals have been made of tropical moths, and most relate to changes across wet and dry seasons, with this cycle leading to seasonal peaks in richness and phenological patterns collectively implying that weather and host plant availability may be drivers of seasonal abundance and richness and influence activity and mortality. Temperature and rainfall both influence Lepidoptera abundance, but with varied trends, and these are sometimes difficult to investigate. In other studies, mass flowering in the high dry season or transition to this may be associated with the diversity of adult Geometridae (Intachat et al. 2001) and Sphingidae (Cruz-Neto et al. 2011), a trend found repeatedly amongst the more numerous studies of tropical forest butterflies. Practical hindrances arise. In some places, it may be difficult or impossible to sample moths effectively during the wet season. On Mount Cameroon, West Africa, persistent heavy rain prevented the use of both bait traps and light traps, so sampling was restricted to other seasons (Maicher et al. 2018). The use of these methods in the other three seasons (transition from wet to dry, high dry and transition from dry to wet) allowed the interpretation of 559 morphospecies. Because Mount Cameroon is one of the world’s wettest regions, Maicher et al. suggested that the moth fauna might manifest one of the greatest natural differences between wet and dry seasons. As well as butterflies, fruit-feeding moths, Arctiinae, Sphingidae, Saturniidae and Eupterotidae were analysed. Only two of these moth groups (fruit feeders, Arctiinae) showed strong compositional changes across seasons, whilst the three other taxa (all with non-feeding adults) lacked clear seasonal patterns. Diversity was generally highest in the high dry season and either increased (fruit feeders, Arctiinae, Saturniidae), remained similar (Eupterotidae) or decreased (Sphingidae) during the transition to the wet season. Their strong changes suggested that fruit feeders and Arctiinae showed relatively high seasonal specialisation that perhaps renders their seasonal assemblages sensitive to climate changes. In contrast, in Ecuador, Hilt et al. (2007) found many species of Arctiinae year-round. Seasonality/aseasonality was one of three parameters—together with body size (as a reflection of dispersal ability) and level of host plant specialisation/

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Changes in Moth Assemblages

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generalisation—to distinguish five ‘functional groups’ of Saturniidae on Barro Colorado Island, Panama (Basset et al. 2017). Two groups were ‘seasonal’, both also being large-bodied and relative host specialists. The other, aseasonal, groups were small-bodied and less specialised feeders, suggesting that the availability of food plants may indeed be an important seasonal influence. More generally, as suggested for these silk moths by Basset et al., for assessing the seasonal pattern of moths in the tropics a minimum of quarterly samples may be sufficient to detect ‘dry’ or ‘wet’ season specialists. The major sampling needs for detecting any trends or changes in incidence, abundance and diversity of moths and to encompass the lack of detailed information and undocumented variety of their responses to season and habitat conditions are thus (1) to standardise sampling times to compare the same season(s) and/or (2) to ensure that periods over which sampling occurs are sufficiently long to incorporate such unknown variations in the final outcome. Most of the information from which these trends have become apparent has come from the use of light traps to capture nocturnal moths and changes in catches at intervals over sustained trapping periods. Although phototactic nocturnal moths are not a complete representation of any local moth fauna (many fruit-feeding moths on Mount Cameroon, for example, were thought to be only weakly attracted to light), they comprise a substantial component of this and are ecologically varied and samples are ‘sufficiently large to provide a degree of confidence to identify community patterns from which usable management tools can be derived’ (Ashton et al. 2011). In practice, they are taken widely as surrogates for wider moth representation and even for wider insect diversity. However, considerable caution is needed in assessing light-trap catches in relation to weather, night light (moon phase), individual species flight behaviour and wider activity, and other factors. In his extensive surveys of tussock grassland moths in New Zealand, White (1991) recognised three main groups of taxa that differed in their susceptibility to capture in relation to wind conditions, leading him to use weather factors in helping to standardise his catches and minimise the twin major uncertainties of light-trap data—namely (1) that catches reflect activity so are not strictly unit-area based and (2) that sampling bias is always present and rarely constant. The groups were (1) ‘heavy fliers’ (Hepialidae, Noctuidae), faster-flying species and the last to remain active as wind speeds increase; (2) ‘medium fliers’ (most Crambidae and Geometridae, some Oecophoridae and Tortricidae), with intermediate size and flight prowess, which remained active in light breezes; and (3) ‘light fliers’ (small moths in a variety of families), which could be sampled only in calm conditions or in very gentle breezes. Light-trap samples nevertheless dominate moth surveys purported to show or infer changes or differences in species incidence or diversity and assemblage composition across space or time and in relation to changes in land use. Understanding their biases and limitations is still highly incomplete, although the relevant literature, extending from the early twentieth century, is voluminous—summaries (Muirhead-Thompson 1991; Southwood and Henderson 2000; Samways et al. 2010) emphasise the need to standardise the method used in any monitoring study, to be

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aware of at least some of the biases arising from environmental factors and moth behaviour and to be very cautious over comparing results from surveys using even slightly different methods or light sources. Because different moths may have very different response distances to light, catches from identical traps even a few tens of metres apart may differ in composition, emphasising that a single catch should be regarded as site-specific, as discussed by Butler et al. (1999). Those sensitivities are a major concern in assessing artificial light as a threat to moths and the ways in which light impacts can be reduced (p. 111). An important benefit from many light-trap designs is that the moths are not killed, and unwanted individuals can be liberated after enumeration: they can therefore be used to assess rare species for which any additional imposed mortality could be harmful. For many surveys in lessdocumented faunas, however, the entire catch may need to be retained for further study and analysis. Other sampling (or more general ‘collecting’) methods for moths include Malaise traps (operating continuously so that diurnal and nocturnal taxa are captured, but typically killing the entire catch), pheromone traps (used extensively for pest monitoring, in many cases very specific but employed also to survey Sesiidae and some other moths that are not readily attracted to light), baits (such as fermenting fruit, alcohol or sugar sources, with techniques such as ‘sugaring’ and ‘wine-roping’ developed largely through hobbyist interests) and an array of more general collecting techniques such as using sticky traps, sweep nets and window traps, from all of which moths may be only a tiny proportion of the catch, and perhaps not in a condition suitable for collectors to retain. Each, however, has contributed biological knowledge and conservation perspective. Pheromone lures, combined with sticky traps, used to sample diurnal Zygaenidae in grassland and clear-cuts in Swedish boreal forest, were far more useful than surveys by transect walks (Bergman et al. 2020); transect walks yielded only 10 specimens of two species, compared with pheromone lures yielding 1075 individuals of three species, with far less effort. Care may be needed to avoid oversampling of rare species by any such method in which individuals are killed. Any such species known from sites should be targeted for early detection, and their discovery may lead to modifications in the sampling approach. Thus, it may be possible for pheromone trapping to harm the target population of a rare species by removal of males—although in many cases those individuals may be released unharmed. The principles of using moth pheromones as attractants are based largely on the use of female moth pheromones to attract males—a method long known to collectors seeking to expand their series of desirable or rare species by exposing caged virgin female moths in suitable areas—and Larsson (2016) advocated that monitoring with pheromones ‘can be applied widely for conservation of rare and threatened insects’, building on the wider experiences from monitoring in pest management and expanding their current involvements considerably. Essentially, the increased use of pheromone-based traps ‘could vastly improve our ability to monitor specific species with unprecedented spatiotemporal resolution, with minimum effort and limited risk to target populations’ (Larsson 2016).

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Less conventionally (and traditionally far less appealing to collectors who seek to pin and set captures as ‘cabinet specimens’), the liquid-preserved catches of Malaise traps can be assessed by DNA barcoding to give information on diversity. However, with care, molecular data from Malaise-trapped moths can indeed be augmented by cabinet specimens prepared from alcohol-preserved samples (Schmidt et al. 2019) for conventional morphological studies. Their protocol for larger moths, including representatives of Pyralidae and Tortricidae in addition to noctuids and geometrids, enabled the preparation of specimens that differed little from freshly collected individuals. In Vietnam, those catches of larentiine Geometridae were far richer in light-trap samples (about 60 species), but the few species (10) captured by Malaise traps included at least one not found at the light. At higher latitudes, light traps are not efficient because of light summer nights, as Aargaard et al. (2017) showed for Norway, and such alternative assessment methods are necessary. In Trondheim (63 °N), the 78 species of Malaise-trapped micromoths represented the largest cohort of Lepidoptera—in Northern Europe, micromoth species outnumber butterflies and larger moths by two to three times. The DNA approach thus allows the inclusion of this largest moth component in those environments. In many light-trap surveys, micromoths are not considered constructively. Transect walk counts, as have become standard for butterfly surveys, are equally suitable for many diurnal moths, such as Zygaenidae, and broader ‘belt transects’ have been used in Australia for the Golden sun-moth (Synemon plana, Castniidae, p. 162) on sites where moths are distributed sparsely and unevenly (Gibson and New 2007). They are a useful ‘citizen science’ (p. 100) approach because a number of participants contribute to the method by walking in a line across the survey area. The values of this direct searching approach for more general moth surveys are limited by the relatively few diurnal moths usually encountered. Thus, in south-west Western Australia, a series of transect walks (totalling 660 km) recorded 33 butterfly species and only three diurnal moth species, two of them Castniidae (Williams 2008a), and a more extensive survey across 46 remnant sites and 3 years in the same region yielded 35 butterflies and five moth species (Williams 2008b). The zygaenid Pollanisus cupreus, found in both surveys, can apparently survive on degraded remnants, but all non-castniid species occurred in rather low numbers. A singleton of the Southern whistling moth (Hecatesia thyridion, Noctuidae) represented a normally crepuscular species that was presumed undersampled and, perhaps, a chance occurrence. Transect surveys allow for moth incidence in the different vegetation/habitat types along the route to be compared but in general are most useful for specific target taxa in Australia. Nocturnal torch-lit transect surveys have been used, although rarely, for particular notable and easily recognisable moths, for which any surveys necessitating capture and mortality are undesirable. This approach was used for the noctuid Luperina nickerlii leechi, known from a single site in Britain (Spalding 1997), and the possible advantages and disadvantages of this method over light-trap surveys were enumerated (Table 3.2). A broader approach to using torch-lit transect surveys for moths (Birkinshaw and Thomas 1999) allowed for appraising associations with particular habitat

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Table 3.2 Advantages and disadvantages of the line transect method over light trapping for surveying moths (Spalding 1997, based on UK experience) Advantages The recording has less effect on the behaviour of the studied moths than does the use of light traps An annual ‘index of abundance’ can be established to facilitate comparisons from year to year If the area of suitable habitat for each species is known, an annual population index can be established The system is cheap and easy, with equipment needed only a long-handled net and a strong torch Samples include moths that are not attracted by other methods Disadvantages Flying and nectaring moths are sampled whilst egg-laying females and sedentary species may be overlooked High-flying moths will not be recorded Moths may be too numerous to identify easily, especially on nights with high moth activity No weather parameters have been established as a basis for a national recording scheme

components along the transect line—but depends on the fauna being sufficiently well-known that the individual species can be recognised clearly. Direct searches for individual species can be space- or time-based or, if the purpose is simply to detect a species, a single discovery can render additional survey redundant. An informative survey for a localised endemic species of Notoreas, then unnamed but later attributed to Notoreas perornata (Geometridae) (Patrick et al. 2010), involved ‘at least half-hour searches’ undertaken by moving through a habitat patch and disturbing roost sites to find adult moths. Caterpillars were also counted and the distinctive larval feeding traces—early instars form leaf mines on the prostrate shrub Pimelea cf urvilleana (Thymelaeaceae)—were also noted (Sinclair 2002). The Pimelea grows on coastal cliffs along the Taranaki coast of New Zealand’s North Island, and 47 food plant patches were found along 50 km of the cliff. All patches were visited repeatedly over 1996–2000, with numbers of plants and interpatch distance recorded in addition to information on the moth. Patch occupancy varied throughout the study (with some vagaries probably reflecting non-detection), but 24 patches yielded Notoreas. These were predominantly larger patches with more than 15 food plants. Severe threats for some patches included cattle trampling and weed encroachment, with rabbit damage (by ring-barking or digging up Pimelea) and localised tourist vehicle parking also noted. This survey led to several management recommendations for this very localised moth, with the likelihood that it is relatively sedentary emphasising the need for the protection of major habitat patches and enrichment of these. Sinclair also recognised that attention to small isolated and unoccupied patches could be distractive unless connectivity with inhabited patches could be increased and that strategies such as moth translocation and management of disturbance (such as by grazing stock) could become important components of practical conservation. Adult moths (especially beyond the northern temperate regions) are both sampled and identified more easily than their larvae, for which laborious searches may still not reveal many of the resident species in an area and that must then be reared to the

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adult stage or characterised by DNA profiles to confirm their identity. However, extended surveys are necessary to appraise moth assemblages. As noted earlier, many species have short-flight seasons and adults are present for only short, characteristic, periods each year. Compiling a tentative species inventory for an area necessitates embracing the entire collective flight season of likely resident moths—by samples taken perhaps at least every month and preferably more frequently. For relative abundance estimates, as Ashton et al. (2011) noted, many moths have a ‘peak’ flight season, with precise timing affected by temperature and so somewhat variable across years, with the ‘tails’ of individuals preceding and following this extending the total period of presence but within which low abundance might give a false impression of scarcity. In the deciduous forest of North America, species turnover between early and late seasons at a site was greater than spatial turnover amongst different forest patches (Summerville and Crist 2003). In another context, because temperature influences development, seasonal variations in flight period at higher elevations can vary more than those at low elevations (Highland et al. 2013). Changes in richness (the total number of species recorded) can often not reflect changes in functional groups or feeding guilds, which may change differently within that total. As Schmidt and Roland (2006) noted, ‘overall diversity measures can mask important community changes’. Moth richness declined with increasing forest fragmentation in Canadian boreal forests, but arboreal species (those depending on trees and shrubs for larval food) were more susceptible to fragmentation than non-arboreal species (those not depending on trees or shrubs but feeding on forbs or grasses), so that changes were driven largely by declines in the former category. For functional conservation, changes in moth diversity should be related to ecological features such as feeding guild wherever possible. Forest moth communities, as an example, are clearly influenced by (1) the tree species and richness present; (2) the composition of shrubs and other understorey vegetation; (3) the proximity and nature of the embedding matrix, as well as (4) stand history and management. However, as Summerville and Crist (2008) pointed out for eastern forest moths of North America, most studies on impacts of forest loss were undertaken over relatively limited spatial scales, with most comparisons of management impacts restricted to smaller scales—so that it was largely unknown whether the moth fauna was conserved adequately in reserves, and the extent to which such refuges need to be enhanced in size and number remained unclear. A list of key processes that may predict fluctuations in forest moth diversity and community composition (Table 3.3) provides a useful template for development in Australia.

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A continuing problem in assessing moth diversity and conservation need is simply that many of the species are trapped (or otherwise detected) in only very low numbers, even in the best-known local faunas, and are poorly known. In many

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Table 3.3 Key processes demonstrated to be predictors of fluctuations in forest Lepidoptera populations, species richness and diversity, and community structure: the three scale-related groups listed by Summerville and Crist (2008), based on northern/eastern forests of North America Within and around tree crowns Host tree effects (leaf palatability, chemistry, position within canopy) Relative abundance/frequency of host tree in stand/landscape Potential interactions between outbreak species and other Lepidoptera Density-dependent changes in host plant quality Long-term climatic variation Heterogeneity of forest type within the regional landscape Oviposition behaviour, female dispersal ability and forest stand composition Amongst forest stands at local and regional scales Floristic composition of forest stand, particularly herbaceous species richness and identity of dominant canopy taxa Stand age, past management history (grazing, historical logging) and canopy architecture The relative importance of invasive shrubs or herbs in the forest understorey Floristic composition of habitat matrix surrounding forest stands, especially when the stand area is small Differences in regional biogeographic history amongst forested ecoregions Spatial geometry of forest stands within landscapes, particularly patterns of stand area and isolation Within management forest ecosystems Changes in tree species diversity within the stand Changes in stand basal area within the stand Changes in dominant canopy taxa within the stand Proportion and composition of bole retained in the managed landscape Spatial pattern of harvest in managed landscapes Method of improvement cut used to regenerate forest stand Non-target effects of application of Bacillus thuringiensis or other agents used in biological control of defoliators

cases, it is also unknown whether those species are residents or simply casual vagrants from elsewhere. Thus, moths sampled in Oregon forests over 5 years comprised a total of 493 species. However, 61 of these were represented by singletons over that period and a further 30 species by two individuals (Highland et al. 2013). In a survey of the inadequately known moth fauna of tropical forest in Malaysia, 538 of the total 1426 species trapped were singletons, and a further 366 species were represented by two or three individuals (Barlow and Woiwod 1989). Similar examples can be listed elsewhere in the world. In Australia’s Wet Tropics Bioregion, Tng et al. (2021) investigated moth diversity through a citizen science project in which moths attracted to light over 191 nights over a single year were photographed, and the images were uploaded to the iNaturalist platform (p. 185) for comment and identification. Of the 906 distinct ‘morphospecies’ (of which only 564 could be formally allocated to named species), 497 were

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represented by singletons, and a species accumulation curve appeared to be not close to reaching an asymptote. Reasons for the incidence of numerous singletons in large samples from local moth faunas have been discussed extensively, as similar examples continue to be reported as a general occurrence amongst invertebrates, whether from extended or short-term investigations. Thus, in a 7-year survey of macromoths across six sites in the Mt Jirisan National Park, South Korea, 275 of the 948 species were found at only one site, and the proportion of singletons at each site ranged from 18.6% to 40% (Choi and An 2013). Assessing whether such apparently low-abundance species have any conservation significance or need through evident decline can only be conjecture unless biological knowledge is available: often, it is not. Many such species may not even be local residents. Barlow and Woiwod (1989) postulated that these might in part reflect ‘a continuous stream of casual visitors from outside the trapping area’, but any such situation cannot at present be confirmed even for such mobile insects. Following ideas advanced by earlier workers, Choi and An suggested that the high incidence of singletons reflects ecologically specialised forest species occurring at low densities or active colonists. Whatever their circumstances, such ‘rare’ moths are encountered very commonly in surveys. Miller et al. (2003) advanced six possible reasons for this, as (1) the caterpillars feed on rare host plants, so local numbers are very limited; (2) the species have narrow environmental tolerances; (3) influences of natural enemies; (4) strong competition occurs with other species; (5) edge distributions of the whole range of species; and (6) insufficient sampling. However, as well as apparent rarity giving such species conservation interest, Miller et al. commented that ‘rare and uncommon species with special or restricted habitat requirements provide an important contribution to the biodiversity within a local landscape’. Incomplete knowledge may increase their conservation profiles, simply because they are encountered rarely, and precaution dictates that they may be genuinely rare or susceptible. Sampling adequacy is very difficult to assess. Inter-species differences in distances of response to light may be substantial and, whilst many moths are presumed to be able to move over at least several km, this is rarely confirmed. Many specialist species are believed widely to disperse rather little (Merckx et al. 2009; Tyler 2020), important knowledge if assessing movement between habitat patches or wider connectivity in the landscape (p. 74). In Highland et al.’s survey, the above and other ‘rare’ moths with collective low abundance over the survey were mostly angiosperm shrub or herb–grass feeders, in contrast to some other studies that demonstrated rare moths to be distributed more evenly across feeding guilds. However, beyond noting their (important) presence, these species are difficult to incorporate in any meaningful analysis of trends, and many authors have opted to interpret moth samples using only species with some declared minimum threshold abundance or representation across a sample series. Drawing on the Rothamsted data, Conrad et al. (2004) used 35 years of information from 1968 to explore population trends of 338 common British macromoth species. At that time, the survey had provided information on more than 730 moth species from records across more than 430 sites, with ‘at least 10 million records’

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accumulated. Slightly fewer than 600 species were each represented by more than 100 captures over that period, and Conrad et al. analysed only those species with >500 captures. Their selection was based also on the number of sites (averaging at least 5/year or, if absent for several consecutive years, captures at an average of at least 5 sites/year over 10 years). Several different analyses implied that (1) populations of many species had declined, and the proportion of species that had declined (54%) was far greater than those which had increased (22%); (2) habitat specialist species had declined across all broad habitat categories; and (3) disproportionate declines in the southern regions reflected declining conditions for many of the moths of southern Britain. Continuing investigation and monitoring of this well-documented fauna have led to the series of documents on ‘The State of Britain’s Larger Moths’ (SBLM), for which the above paper by Conrad et al. (2004) was an important forerunner. This series was launched in 2007 by the organisation ‘Butterfly Conservation’ with the purpose of creating a United Kingdom database of moth records to support conservation. Most recently (Fox et al. 2021), the updated SBLM analysed records over 50 years of light-trap samples (1968–2017) and distribution trends based on sightings accumulated through the National Moth Recording Scheme (NMRS). The data bank thereby also includes records of early stages and species not attracted to light, allowing interpretation from more than 24 million records from the scheme. The trends in abundance and distribution (including site occupancy) were thus based on a formidable array of data covering all species, and from which parallels for the rest of the world from which such data are far more sparse—or do not exist in any comparable form—may be investigated, inferred or indicated. SBLM draws also on key accounts of declines of UK moths (such as Fox 2013; Fox et al. 2014) and how long-term changes may be evaluated, with the UK trends found also amongst moths of several European countries. Many gaps in understanding remain, together with ambiguities in harmonising long-term abundance trends (from SBLM, 41% [175 of 427 species] decreased, 10% [of 210 species] increased and the remaining 49% [210 species] showed non-significant trends) and distribution trends (from NMRS, 325 [165 of 511 species] decreased, 37% [187 species] increased and 315 [159 species] showed non-significant trends). Patterns of change are complex, not least because these trends imply that many moths have simultaneously both declined in abundance and expanded their distributional range. Many British moths—346 of the 487 species for which sufficient data were available— have expanded northward. The causes of many of the documented or inferred changes are still unclear. As Fox (2013) commented ‘although widespread declines of moth faunas have been identified recently from Britain and other countries, knowledge of the underlying causes is scant’. Studies on an increasing and varied suite of species have done much towards clarifying the threats to moths and ways to avoid or counter these. Together with the more numerous such investigations for butterflies, some clear pathways towards conservation status assessments and conservation management continue to be developed, with lessons from these diverse herbivores relevant to much wider biodiversity. However, the steep declines demonstrated for the United Kingdom

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moths are not universal—or, at least, have not been verified to the same extent beyond Europe. As Wagner (2012) remarked, ‘Great heterogeneity in moth trends exists geographically and taxonomically, yielding a complex picture that cautions against ambitious extrapolation and generalisation’, with integrative and statistical issues sometimes confounding the conclusions. However, for Britain, data from 1968 to 2016 showed that declines in moth abundance have occurred across most habitat types, as have declines in biomass (Blumgart et al. 2022). The most severe declines occurred in broad-leaf woodlands but the reasons for this were still unclear—not least because this habitat has increased in the area over the survey period. Increased forest/woodland fragmentation and loss of connectivity imply the need for a broad landscape-scale approach to their conservation. An estimated 60% of the United Kingdom’s moths are believed to rely on semi-natural broad-leaved lowland forest (Young 1997; Slade et al. 2013), giving those forests and woodlands significant conservation values and an important focus for study. Long-term monitoring surveys of insects are a luxury for most of the world, and many commentators have urged the importance of these both as inventories of diversity and to establish baselines against which future changes can be monitored. Wagner et al. (2021) highlighted the particular importance of gaining further information for moths of the tropics and the southern temperate regions. However, the conservation of moths must generally be pursued without any such information other than, rarely, by comparison with other organisms. A few studies of trends in local butterfly assemblages (in Australia for the trends in butterflies in outer Melbourne as urbanisation proceeds: Braby et al. 2021) imply that species of moths might be lost or affected by similar causes, but direct evidence for urban moth declines in Australia is largely anecdotal rather than accumulated deliberately. Susceptibility or vulnerability of moths can relate to a range of different ecological traits and life history features, in addition to the key features of food specificity and range size that are implicated frequently. Narrow-range specialists are generally deemed those species most likely to become extinct, as demonstrated by many butterfly studies. This wider variety of influences collectively affects how species respond to disturbances (as ‘response traits’) and affect ecosystem processes (as ‘effect traits’) (Uhl et al. 2021). Habitat (namely resource) diversity is integral to supporting high moth diversity, but other features considered to predispose moths to increased rates of decline include large size, small geographical ranges, low dispersal ability and being univoltine. All these traits are cited widely for insects. Short-flight seasons and development patterns with the egg stage overwintering are also possible correlates of vulnerability but, following Mattila et al. (2006), identifying those traits that predispose any particular species to the risk of extinction can help direct conservation efforts towards especially vulnerable taxa. Mattila et al.’s pioneering study involved the 306 species of Noctuidae in Finland that have resident or fluctuating populations, so excluding migratory species and recent colonists. The data available was uneven across the traits analysed, but the outcome, echoed in several more recent surveys, was that no single trait alone explained the risk of extinction and that considerable species-specific information is needed before those traits of greatest concern can be determined reliably.

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However, those traits of greatest relevance and concern in assessing extinction risk are also those that predicted distribution, so these are linked strongly in conservation planning. Those traits, in part recapitulating the above, were listed as larval specificity, the overwintering stage(s) (with species overwintering as adults at greatest risk), length of flight period and the food plant distribution for monophagous species. Following a study in Britain (Quinn et al. 1997), most monophagous species (of Geometridae and Noctuidae) occupied only small proportions of their host plant range, so other constraints on range occurred. Factors such as climate change or local differences may affect these interacting species differently (p. 90). The extensive data on British moths were examined also in relation to factors linked with extinction, in which Coulthard et al. (2019) also included ‘photoperiod activity’—whether the adults were diurnal, nocturnal or crepuscular—but noted that the relationships between the various factors were ‘complicated, interlinked and sometimes conflicting’. Vulnerability from nocturnal activity links with attraction to lights and its complex impacts (p. 111). Modelling from the extensive data on the 337 species of ‘common or widespread’ moths with sufficient information, however, endorsed several of the above trend correlates. Larger long-winged moths, generally considered those having better dispersal ability and flight speeds (reducing susceptibility to local disturbances and habitat fragmentation), were the most significantly declining species, suggested also to be related to large area requirements as a trend largely independent of fragmentation and dispersal effects. Again, from Coulthard et al., ‘anomalies occur in any such attempted overview’ and ‘the relationship between population trends and ecological traits is not straightforward’. Any assemblage of moths is likely to include ‘winners’, ‘losers’ and species not noticeably affected as environments change. Some further generalisations may occur. As examples from Britain (1) an increased abundance of several lichenfeeding footman moths (Erebidae: Arctiinae) may be related to an increase in nitrophilic lichens in agricultural landscapes, and (2) non-woodland species linked with grassland (with increased soil nitrogen leading to floristic changes), heathland or wetland habitats were more likely to decline than forest/woodland species. The drivers of ‘winners’ vary greatly, as demonstrated for 51 British macromoths, which have all become more common since the later 1960s and which are ecologically diverse (Boyes et al. 2019). The trends can perhaps be discerned only from longterm continuous monitoring, because they are commonly not linear and occur at different rates and extents. Twenty-one species more than doubled their British range over that period, and this was commonly accompanied by increased local abundance. However, the winners included widespread ecological generalists (polyphagous and found in various habitats), restricted ecological specialists (10 species, nine of them associated strongly with woodland) and recent colonists. The last may have been underrepresented, because only two of the more than 40 macromoths colonising Britain since the early twentieth century had accumulated enough trap records (in the Rothamsted Insect Survey) to be included. Their table of possible hypotheses to ‘explain’ the diversity of the trends found includes many influences that could constructively be explored elsewhere (Table 3.4). Relative numbers of winners and losers are rarely available from other places. Twelve years of sampling

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Table 3.4 Contributory hypotheses that may help to explain the diversity of positive trends observed in British moths (Boyes et al. 2019, used under CC-BY-4.0 [http://creativecommons. org/licences/by/4.0/]) Proposed cause ‘Background’ biodiversity change Conservation and policy action Habitat change and novel ecosystems Climate change Colonisation of novel genotypes

Evolutionary adaptation Network disruption

Description Observed trends may not represent recent responses to anthropogenic change, but rather the continuation of long-term evolutionary trajectories There is significant expenditure on conservation in Britain, including direct habitat management for threatened species and agrienvironment schemes for more widespread species Varied outcomes of modern agricultural practices include opportunity for some species; novel habitats such as forestry plantations and urban areas may benefit some species May provide increasingly favourable conditions for some species, enabling range extensions and larger populations Warming leading to increased migration of moths to Britain; influxes likely to contain cryptic diversity of resident species that may be better adapted to contemporary conditions or engender hybrid vigour Ability to adapt effectively to the extreme selective forces of anthropogenic changes Positive trends in ‘winners’ could be linked causally to negative trends in ‘losers’, e.g., may become more abundant after the loss of a competitor or natural enemy

tiger moths (Erebidae: Arctiinae) of Barro Colorado Island, Panama, enabled appraisal of the trends for 96 species (Lamarre et al. 2022). Most species had stable (20 species) or increasing (62) population trends, and only 14 species were clearly declining. This analysis represented the more common moths amongst the regional pool of 188 species observed and for which trends could be modelled adequately. The variety of trends was attributed to species-specific sensitivity to climate conditions. Positive trends were most distinct amongst moths that were most abundant with higher precipitation and higher temperatures, so ‘climate sensitivity’ trends were the best predictors of population trends. Two further long-term light-trap surveys of moths in Europe have augmented aspects of the British analyses, by providing valuable perspective on changes amongst macromoths over time at particular sites in Hungary (Valtonen et al. 2017) and south-eastern Norway (Burner et al. 2021). Hungarian data were from daily captures of moths over 1962–2009 from seven sites in the forest and on forest margins, with traps operating each night over the major flight season of March– December each year. Changes in land use that broadly mirrored those over much of central Europe were listed as increased forest cover (in part reflecting a national afforestation programme) and decreased grassland cover (in part, as forest increased). Temperature also increased. Collectively, 878 species of macromoths were included in interpretations, and the main trends reported were regional loss of species and increased homogenisation of the moth assemblages across sites. A comparison of catches between the first (1962–1985) and second (1986–2009)

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survey periods showed that 74 species had disappeared, whilst 772 were present in both periods, and 32 species occurred only in the later period. In addition, long-term trends in abundance were assessed and modelled for the 387 species with 500 or more individuals recorded over the survey, and ecological correlates of changes were evaluated. The most important variables linked with species loss were a narrow European distribution, narrow dietary breadth and the preferred habitats of grassland, cliffs, rocks or sand dunes. For example (Fig. 3.1), Valtonen et al. found that monophagous species had seven times the chance of polyphagous species disappearing, and species from the above habitats were four times more likely to be lost than those from the broad-leaved forest. Species with greater wingspan were the most likely to be ‘new species’. Reduced heterogeneity in moth assemblages was very clear as specialists and narrow-range species disappeared. The Norwegian study (Burner et al. 2021) included 30 years (1984–2013) of moth captures at a single site, a garden edge surrounded by forest, from a light trap operated from early June to mid-October each year. Trapping for 3 nights/week yielded 808 moth species (from 43 families) with a total of 97,032 individuals. Of these, 336 species were found in 10 or more years, and trends from these, linked with major habitats (Table 3.5), showed far more declines (especially amongst forest species) than increases. As for other studies, the interactions of climate change and changes in land use are complex and render attribution of moth changes to either problematical—but in this region of southern Norway declines in moth richness and diversity were indeed clear. Most long-term comparisons of moth faunas inevitably draw on information accumulated by unknown sampling/collecting intensity in the earlier periods and unknown interpretative biases when compared with more recent data. Thus, a comparison of historical (from 1933) and recent macromoth surveys (up to 2012)—an overall span of 85 years—in a coastal pine wood reserve in Italy revealed that the proportion of habitat generalist species increased from 20% to 33% (Wolfling et al. 2019). The proportions of more specialised woodland and open habitat species declined by 10%, and 18 open habitat and 10 reedy habitat species were lost. This loss of specialists was attributed to vegetation succession and the reserve’s isolation. Wolfling et al. inferred that the abundance and proportional richness of generalist species reflected increased habitat homogeneity, circumstances that might reduce suitability for the increasingly vulnerable specialist taxa. From surveys of macromoths in German forests accumulated over four decades (summarised in Table 3.6), Roth et al. (2021) also demonstrated substantial declines of habitat specialists and also of ‘dark-coloured’ moths, the latter probably reflecting temperature changes through influences of climate warming. Richness, abundance and biomass of dark moths all decreased significantly more than ‘light-coloured’ moths, but with some variations across the three forest categories sampled. Elsewhere in the world, opportunities to re-survey well-studied collecting sites after long intervals are very sporadic and set against highly incomplete knowledge of historical incidences and the methods employed to assess them. Nevertheless, the confirmed persistence of species over long intervals is reassuring, disappearances may be evaluated against wider awareness, and previously unreported species may

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Fig. 3.1 Proportions of European moth species over two study periods (before and after 1985) shown in relation to distribution, dietary breadth and habitat; proportions are shown as species present in the first half of the study period that was either absent (black) or present (open) in the second period; numbers of species in each category are shown. Habitats are: a, broad-leaved forest; b, coniferous forest; c, glades; d, hedges; e, dry grassland; f, mesic grassland; g, heath; h, rocks; I, ruderal; j, water edge; k, wetland (after Valtonen et al. 2017)

in part represent recent arrivals and those overlooked earlier. A comparison of two forest sites on the island of Hawaii (Kilauea, 93 moth species over 1911–1912; Upper Waiakea Forest Reserve, >94 species, 1998–2000) about 15 km apart suggested such trends (Giffin 2007). About 20 species from the earlier Kilauea collections were not found in the later survey, whilst 42 additional species were

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Table 3.5 Trends of moth species in southeast Norway, based on a 30-year time series and including all species detected in 10 or more years. Numbers of species (percentage in brackets) shown as declining, uncertain or increasing for major food plant habitat categories (Burner et al. 2021, used under CC-BY-4.0 [http://creativecommons.org/licences/by/4.0/]) Habitat Forest Garden Meadow Meadow/forest Unknown/other Total

N 162 24 67 51 32 336

Declining 32 (19.7) 7 (29.2) 8 (11.9) 8 (15.7) 4 (12.5) 59 (17.6)

Uncertain 121 (74.7) 17 (70.8) 55 (82.1) 39 (76.5) 26 (81.2) 258 (76.7)

Increasing 9 (5.6) 0 4 (6.0) 4 (7.8) 2 (6.3) 19 (5.7)

Table 3.6 Four conclusions from surveys of nocturnal moths in central European forests undertaken to assess regional declines across data sets collected over four decades (Roth et al. 2021, used under CC-BY-3.0 [http://creativecommons.org/licences/by/3.0/]) Insect decline in such hyperdiverse groups affects species richness, abundance and biomass in the forests. The pronounced decline in host specialists suggests that habitat loss is an important driver of the observed decline. The more severe decline in dark-coloured species might be an indication of global warming as a potential driver. The trends in coppiced oak forest indicate that maintaining complex and diverse forest ecosystems through active management may be a promising conservation strategy to counteract negative trends.

recorded. Many of the recurrent species were rare in both surveys, and the number of non-native species doubled. This increase was attributed to a combination of more recent introductions and increased forestry and urban development in the area. Surveys continued over several consecutive years are rare for most tropical moth faunas, but provide information on richness and relative abundance, and patterns of change across seasons and sites. They may reveal that those patterns differ across major taxa, or that shorter-term surveys may markedly oversimplify interpretations of variations. In Mt Jirisan National Park, Noctuoidea and Geometroidea were by far the predominant moth groups captured over a 7-year programme (Choi and An 2013, p. 51), with a strong mid-elevational distribution peak (Fig. 3.2). Whilst Noctuidae had the higher richness, Geometridae yielded a higher proportion of individuals. Additionally, the relative representation of different common species may change markedly over time either as general trends or abrupt ‘outbreaks’. The abundance of two common moth species over that period. Hydrillodes morosa (Erebidae, a detritivore) showed an early peak, whilst Alcis angulifera (Geometridae, with polyphagous larvae) was most abundant in year 6 of the survey and declined in the following year. As Choi and An also discussed, their survey could not address several important themes—whilst displaying patterns of moth distribution and its distribution, explaining that pattern remained mostly conjectures. Those themes, all of the far broader interest, included (1) what factors cause spatial and temporal

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Fig 3.2 Elevational distribution of moth species richness (total species collected in 2007 and 2008) at different elevations in Mt Jirisan National Park, South Korea (Choi and An 2010, used and slightly simplified under CC-BY-4.0 [https:// creativecommons.org/ licences/by/4.0/])

variations in moth populations in a forest ecosystem; (2) what factors lead to the appearance of different moth species, thus emphasising the poor knowledge of many trophic and other interactions in which they participate; and (3) why there are indeed so many ‘rare’ species.

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Intachat J, Holloway JD, Staines H (2001) Effects of weather and phenology on the abundance and diversity of geometroid moths in a natural Malaysian tropical rain forest. J Trop Ecol 17:3411– 3429 Kuris AM (2003) Did biological control cause extinction of the coconut moth, Levuana iridescens, in Fiji? Biol Invas 5:133–141 Lamarre GPA, Pardikes NA, Segar S, Hackforth CN, Laguerre M et al (2022) More winners than losers over 12 years of monitoring tiger moths (Erebidae: Arctiinae) on Barro Colorado Island, Panama. Biol Lett 18:20210519. https://doi.org/10.1098/rsbl.2021.0519 Larsson MC (2016) Pheromones and other semiochemicals for monitoring rare and endangered species. J Chem Ecol 42:853–868. https://doi.org/10.1007/s10886-016-0753-4 Lees DC, Smith NG (1991) Food plant associations of the Uraniinae (Uraniidae) and their systematic, evolutionary and ecological significance. J Lepid Soc 45:296–347 MacArthur RH (1955) Fluctuations of animal populations and a measure of community stability. Ecology 36:533–536 Maicher V, Safian S, Murkwe M, Przybylowicz L, Janecek S et al (2018) Flying between raindrops: strong seasonal turnover of several Lepidoptera groups in lowland rainforests of Mount Cameroon. Ecol Evol 8:12761–12772 Mattila N, Kaitala V, Komonen A, Kotiaho JS, Paivinen J (2006) Ecological determinants of distribution decline and risk of extinction in moths. Conserv Biol 20:1161–1168 Merckx T, Feber RE, Dylieu RL, Townsend MC, Parsons MS (2009) Effects of field margins on moths depends on species mobility: field-based evidence for landscape-scale conservation. Agric Ecosyst Environ 129:302–309 Miller JC, Hammond PC, Ross DNR (2003) Distribution and functional roles of rare and uncommon moths (Lepidoptera: Noctuidae: Plusiinae) across a coniferous forest landscape. Ann Entomol Soc Am 96:847–855 Muirhead-Thompson RC (1991) Trap responses of flying insects: the influence of trap design on capture efficiency. Academic Press, London Nazari V, Schmidt BC, Prosser S, Hebert PDN (2016) Century-old DNA barcodes reveal phylogenetic placement of the extinct Jamaican Sunset moth, Urania sloanus Cramer (Lepidoptera: Uraniidae). PLoS ONE 11:e0164405. https://doi.org/10.1371/journal.pone.0164405 Nazari V, Tarmann GM, Efetov KA (2019) Phylogenetic position of the ‘extinct’ Fijian coconut moth, Levuana iridescens (Lepidoptera: Zygaenidae). PLoS ONE 14(12):e0225590. https://doi. org/10.1371/journal.pone.0225590 Nieminen M (1996) Risk of population extinction in moths: effects of plant characteristics. Oikos 76:475–484 Patrick BH (2000) Conservation status of two rare New Zealand geometrid moths. Science for Conservation 145:1–21 Patrick BH (2014) Ecology and conservation of the rare moth Asaphodes frivola Meyrick. The Weta 47:17–38 Patrick BH, Hoare RJB, Rhode BE (2010) Taxonomy and conservation of allopatric moth populations: a revisionary study of the Notoreas perornata Walker complex (Lepidoptera: Geometridae: Larentiinae), with special reference to southern New Zealand. N Z J Zool 37: 257–283 Quinn R, Gaston K, Blackburn T, Eversham B (1997) Abundance-range size relationships of macrolepidoptera in Britain: the effects of taxonomy and life-history variables. Ecol Entomol 22:453–461. https://doi.org/10.1046/j.1365-2311.1997.0090.X Roth N, Hacker HH, Heidrich L, Friess N, Garcia-Barros E et al (2021) Host specificity and species colouration mediate the regional decline of nocturnal moths in central European forests. Ecography 44:941–952 Samways MJ, McGeoch MA, New TR (2010) Insect conservation. A handbook of approaches and methods. Oxford University Press, Oxford Schmidt BC, Roland J (2006) Moth diversity in a fragmented habitat: importance of functional groups and landscape scale in the boreal forest. Ann Entomol Soc Am 99:1110–1120

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Schmidt O, Schmidt S, Hauser CL, Hausmann A, Van Vu L (2019) Using Malaise traps for collecting Lepidoptera (Insecta), with notes on the preparation of Macrolepidoptera from ethanol. Biodiv Data J 7:e32192. https://doi.org/10.3897/BDJ.7.e32192 Sinclair LJ (2002) Distribution and conservation requirements of Notoreas sp., an unnamed geometrid moth on the Taranaki coast, North Island, New Zealand. N Z J Zool 29:311–322 Slade EM, Merckx T, Riutta T, Berber DP, Redhead D et al (2013) Life-history traits and landscape characteristics predict macro-moth responses to forest fragmentation. Ecology 94:1519–1530 Smith NG (1983) Host-plant toxicity and migration in the day-flying moth Urania. Fla Entomol 66: 76–85 Southwood TRE, Henderson PA (2000) Ecological methods, 3rd edn. Blackwell, Oxford Spalding A (1997) The use of the butterfly transect method for the study of the nocturnal moth Luperina nickerlii leechi Goater (Lepidoptera: Noctuidae) and its possible application to other species. Biol Conserv 80:147–152 Spalding A (2015) Loe Bar and the Sandhill Rustic moth; the biogeography, ecology and history of a coastal shingle bar. Brill, Leiden Summerville KS (2004) Functional groups and species replacement testing for the effects of habitat loss on moth communities. J Lepidopt Soc 58:114–117 Summerville KS, Crist TO (2003) Determinants of lepidopteran community composition and species diversity in eastern deciduous forests; roles of season, ecoregion and patch size. Oikos 100:134–148 Summerville KS, Crist TO (2008) Structure and conservation of lepidopteran communities in managed forests of northeastern North America: a review. Can Entomol 140:475–494 Tng DYP, Apgaua DMG, Fisher NJ, Fazio VW III (2021) Moth species richness in an upland tropical rainforest: a citizen scientist assisted study. https://doi.org/10.1101/2021.11.07.467659. (preprint posted 8 Nov 2021) Tyler T (2020) Relationship between moth (night active Lepidoptera) diversity and vegetation characteristics in southern Sweden. J Insect Conserv 24:1005–1015 Uhl B, Wolfling M, Fiedler K (2021) Qualitative and quantitative loss of habitat at different spatial scales affects functional moth diversity. Front Ecol Evol 9:637371. https://doi.org/10.3389/ fevo.2021.637371 Upton MS (1997) A twelve-year larval diapause in the Queensland Kauri moth, Agathiphaga queenslandensis Dumbleton (Lepidoptera: Agathiphagidae). Entomologist 116:142–143 Valtonen A, Hirka A, Szocs L, Ayres MP, Roininen H, Csoka G (2017) Long-term species loss and homogenization of moth communities in Central Europe. J Anim Ecol 86:730–738 Wagner DL (2012) Moth decline in the northeastern United States. News Lepidopt Soc 54:52–56 Wagner DL, Fox R, Salcido DM, Dyer LA (2021) A window to the world of global insect declines: moth biodiversity trends are complex and heterogeneous. Proc Nat Acad Sci 118(2): e2002549117 White EG (1991) The changing abundance of moths in a tussock grassland, 1962-1989, and 50- to 70-year trends. N Z J Ecol 15:5–22 Williams MR (2008a) Assessing diversity of diurnal Lepidoptera in habitat fragments: testing the efficiency of strip transects. Environ Entomol 37:1313–1322 Williams MR (2008b) Butterflies and day-flying moths in a fragmented urban landscape, southwest Western Australia: patterns of species richness. Pac Conserv Biol 15:32–46 Wolfling M, Uhl B, Fiedler K (2019) Multi-decadal surveys in a Mediterranean forest reserve – do succession and isolation drive moth species richness? Nat Conserv 35:25–40 Young MR (1997) The natural history of moths. Poyser, London

Chapter 4

Causes for Concern: Habitat Change as the Major Imposed Threat to Moths

4.1

Introduction

The wide spectrum of imposed environmental changes that affect insect populations and may link with extinction risk or declines have all been cited and discussed widely for moths and are founded in awareness that most moths are in some way sensitive to changes in their environments and may become threatened with declines or loss. ‘Threats’ have been categorised in various ways, many following the broad categories noted by Salafsky et al. (2008), but whatever divisions are used, a nominal threat may have three levels of severity and impact. The first (‘major threat’) is the broadest consideration, the second level (‘sub-threat’) is more defined as a facet of a major threat and the third level (‘specific threat’) applies to more individual contexts (Kearney et al. 2020). The definition of threats in any particular context is a basis for recognising a species as in need of conservation, with the hierarchy of categories based on the World Conservation Union’s Red Data List categories (p. 152) used widely and modified as needed for particular scenarios. In principle, any changes to a terrestrial environment—whether the loss or changed supply of vital resources, intrusions by other organisms, chemical pollution or less tangible influences such as climate warming—potentially affect resident species and the ways in which they interact. Each such change could thereby represent a ‘threat’ if it causes perceived detrimental changes such as local extinctions or demonstrable declines of abundance or distribution. Any attempt to enumerate threats to a biologically diverse and varied insect group defies full evaluation, which may be strongly context-dependent. Nevertheless, major categories of ‘threat’ can be distinguished, as below, and their prevention and amelioration are the foundation of much conservation activity. For moths, as a predominantly herbivorous, ecologically varied, diverse insect group containing many localised specialist species, the major evidence of threat impacts relates to changes in incidence, abundance, distribution, and assemblage richness and composition. The universal theme of ‘habitat change’, comprising direct loss and degradation of key resources, © The Author(s), under exclusive license to Springer Nature Switzerland AG 2023 T. R. New, The Other Lepidoptera: Moth Conservation in Australia, https://doi.org/10.1007/978-3-031-32103-0_4

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pervades most conservation concerns, but impacts are related also to many contributing factors. These are discussed further in Chap. 5, but complexities of interacting threats are noted here to provide perspective. Allocation of any formal ‘threat status’ to a moth species involves assessment of its distribution, abundance and trends in relation to the range of threatening processes detected or postulated and their actual or postulated impacts. Ensuing management or other attention to such ‘listed species’ (whether or not they are formally recognised by regulation and accorded priority for attention) may be determined by any such designated priority. Such ‘single-species’ conservation programmes have traditionally dominated Lepidoptera conservation, but increasingly those species are incorporated into the wider contexts of local assemblages, environmental conditions and conjoint threats. In many cases, awareness of threats to moths has flowed from their better-documented impacts on particular butterfly species, or more widely to regional or local assemblages and communities, and even to the wider contexts of national or global changes and concerns. In many cases, the direct impacts of change are very obvious, but in many other situations they can only be reasonably inferred amongst the multitude of interacting influences and cascade effects. Different ‘threats’ (often termed ‘stressors’) to moths can act alone, synergistically, additively or antagonistically (Wagner et al. 2021). However, many are associated in some way with anthropogenic changes in land use that collectively embrace direct losses and degradation of habitats, perhaps most frequently with vegetation clearing to accommodate needs such as agricultural intensification, urbanisation and industrial and recreational developments. In turn, the processes often include the impacts of alien animal and plant species, pesticide and fertiliser applications, pollution and other waste removal and are universally overlain by climate changes (Chap. 5). The last is regarded widely as an inevitable superimposition of all the more tangible changes to terrestrial and freshwater environments that insects inhabit. Whilst one or other of these may be the primary and most obvious concern in any given context, it is only rarely likely to be acting alone, and unravelling the relative impacts of co-occurring stressors is extraordinarily difficult, as is interpreting the components of broadly defined threats. The variety and characteristics of urban or agricultural habitats, for example, represent consequences of the initial loss of native vegetation, replacement by other plants (many of them not native species) and subsequent management and human intrusions, including loss of area to construction and development. Nevertheless, agricultural intensification and habitat loss are viewed widely as key drivers of moth decline with management designed, where possible, to emulate natural disturbance regimes rather than anthropogenic impositions. Few such studies have focused on moths. The relative impacts of natural wildfires and clear-felling of boreal forest in Canada were compared by light-trap catches of moths across sites with these treatments about 5 years previously (Chaundy-Smart et al. 2012). Similar richness occurred in the two regimes (204 species in burned sites, 211 in clear-fell) and the same species were predominant in both; both also yielded many species in very low numbers, but more species (9) were significantly more abundant in burned areas than in clear-fell (3). Eight were considered ‘burn specialists’, but this study

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demonstrated the difficulties of general presumptions that different disturbances may have similar effects. In short, the factors leading to extinction or increased vulnerability of moths are complex and commonly specific to the habitats or particular locations and taxa influenced. Understanding these factors is key to assessing conservation need and planning management, against a background of imperfectly defined ‘natural disturbances’ to which local faunas may be adapted. Increased vulnerability is almost inevitable once primary habitats are lost or degraded, and intact fragments become more susceptible to a variety of stressors that might be ‘buffered’ to a greater extent in intact areas. Two British cases indicate the problems of interpretation that arise in even this best-documented moth fauna. The formerly more widespread Marsh moth, Athetis pallustris (Noctuidae), declined to remain only on dry sandy dune grasslands near the coast of Lincolnshire, with some of the sites designated as protected reserves. The causes of wide fluctuations in moth numbers are largely unknown, and the county’s Biodiversity Action Plan for Athetis noted that ‘the main threat is loss through ignorance’, reflecting poor knowledge of the moth’s biology and how it may respond to small changes in site condition and management. Second, the Essex emerald moth, Thetidia smaragdaria maritima (Geometridae), is associated with coastal salt marshes in southern England, where the last-known British populations died out in the range counties of Essex (in 1985) and Kent (1990–1991). The trajectory of loss and measures to counter this has been documented extensively (Waring 1993). Numerous interacting factors were implicated: Waring discussed inappropriate grazing, slashing and burning, the loss and increased fragmentation of suitable habitat, the possible susceptibility to genetic changes in the small populations and overcollecting. Impacts on co-occurring species of increased habitat isolation and loss, as a universal conservation concern, embrace not only the broad ‘generalist/specialist differences’ most commonly invoked but also more subtle and difficult-to-assess differences between even closely related taxa. The contrasting ecological requirements of two closely related burnet moths (Zygaena carniolica, Z. viciae; Zygaenidae) on European calcareous grasslands were associated with different responses to habitat loss and suggested that different conservation strategies were needed for each species (Habel et al. 2012). Comparisons of genetic variability and morphological variability (assessed by fluctuating asymmetry of wing markings) across populations showed that (1) genetic variability in Z. carniolica is low, whilst Z. viciae is more variable with individual populations showing differences, and (2) morphological variability is low for Z. carniolica and much higher for Z. viciae. These contrasts were interpreted as reflecting opposite responses to recent grassland loss and population isolation. Habel et al. suggested that somewhat different conservation priorities were needed. Z. carniolica did not suffer greatly from increased isolation so may be conserved by the preservation of local reserves, but Z. viciae conservation should concentrate on the populations that still have high genetic variability, as the best sources of material for any future efforts involving genetic refreshment of other, more impoverished, populations.

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Numerous studies have attempted to correlate nocturnal moth (in most cases, only ‘macromoth’) species abundance or assemblage diversity with environmental factors, with local plant species richness and site elevation frequently inferred to be predictors of diversity and distributions, as well as the disturbances themselves. As broad generalities (Dar and Jamal 2021), many moths respond to vegetation changes, including succession and human disturbance, all of which have been shown or inferred repeatedly over extended surveys. Factors such as varying degrees of correlation with vegetation structure and composition, phenology of particular host plants, restricted or specialised habitats, extent of disturbance and departure from presumed natural conditions and influences of microclimate and natural enemies are all widespread but, notwithstanding the general influences of each of these variables, the different local conditions for each study may give very different outcomes and affect the relative impacts of different disturbances. In short, the main drivers of transformative land use link with human needs and human population increase. Regional and local differences, of course, occur but threat determinations and evaluations in any particular circumstance or more broadly are a core dictate of conservation need, and any such evaluation demonstrates the complexity involved. For moths in Britain, Fox (2013) considered the five main broad causes of biodiversity loss and—far more restricted to nocturnal insects— noted light pollution as an important additional potential driver of moth abundance and richness. These major drivers were listed as (1) habitat loss, degradation and fragmentation (such as through agricultural management, woodland management and urbanisation); (2) chemical pollution; (3) climate change; (4) non-native species; (5) exploitation of populations; and(6) light pollution. In Australia, the impacts of fire are also a major transformative influence. These major themes are discussed in the sequence below (habitat) and in the following chapter. They are not in any way restricted to moths and are all widespread concerns. Syndromes such as ‘urbanisation’ or ‘agricultural intensification’ include several of these key drivers, with individual or separate impacts often not clear but combining to negatively affect moths and many other insects. Synergisms between different ‘threats’ can become complex and uncertain. For example, the processes comprising ‘urbanisation’ not only involve habitat loss and fragmentation, but also can increase warming and drying above the regional levels (Wilson and Fox 2021). A great variety of agrochemicals are used widely in home gardens and public open spaces in towns and cities, introduced species of plants and insects abound and increased light pollution, all augment the major loss of natural habitats that largely defines urban environments. Some impacts of urbanisation on Lepidoptera are not initially obvious, as having subtle effects on life histories or development. In particular, the ‘urban heat island effect’ (that urban areas are warmer than nearby rural areas) and artificial lighting at night (ALAN, p. 111) may influence local temperatures and photoperiods, respectively, in turn inducing differences in moth phenology and development such as through timing of diapause induction (Merckx et al. 2021). In Finland and Sweden, their long-term records of the geometrid Chiasmia clathrata (Latticed heath) in cities and rural areas implied that flight seasons in cities had become longer and ended later, so that timing of diapause

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might be changed—with such urbanisation impacts thereby influencing capability for local adaptation and evolution. The complexity of food webs in which moths participate raises many uncertainties—and fears—over the outcomes of moth declines in wider communities. Conservation has focused largely on the relationships between moths and their larval food plants, and adult nectar sources are considered to a lesser extent. Many of these associations are relatively easy to study and manipulate, with the availability of suitable larval food plants central to much conservation planning. Far less amenable to study, but involving vast numbers of poorly known species are their associations with the numerous parasitoid wasps and flies that attack moth hosts, mostly during their early stages. The reality was expressed by Stireman and Shaw (2022) noting that in general parasitoids ‘are so poorly known that we have little idea how many species have already gone extinct or may currently be tottering on the brink due to anthropogenic changes to the environment’. Threats to parasitoids parallel those discussed for their host moths, with the loss of their hosts themselves a major component of decline—perhaps mainly for specialist parasitoids lacking alternative hosts. Links with moth habitat loss equate to rendering generalist parasitoids susceptible to declines and local extinctions, especially in small habitat fragments. Stireman and Shaw suggested that parasitoids of caterpillars are likely to be amongst the first components of complex ‘plant–caterpillar–natural enemy’ tritrophic systems to be lost, reflecting the wide assumption that higher trophic levels in such systems may be the most vulnerable. Precise outcomes are largely conjecture, but may be wide-ranging and substantial. Loss of parasitoids—and consequent wider declines in parasitisation levels and caterpillar (or other growth stages) mortality—may dramatically affect moth population dynamics, as well as lead to overall simplification of complex food webs that may then become more susceptible to other environmental disturbances, through outcomes such as the increased likelihood of collapse with climate changes and habitat fragmentation. As with the host moth taxa, host-specific parasitoids may be increasingly lost, whilst generalists become more predominant. Consequences noted by Stireman and Shaw (2022) included a greater extent of competition amongst caterpillars that shared enemy species and changes to food webs affecting their stability and resistance to disturbances. The cascade effects from the loss of a single host moth species on which specific parasitoids (or other natural enemies) depend are extremely difficult to predict, but may ramify widely through the local community. That climate change is likely to affect participants—even those in specific tritrophic associations—in food webs differently simply emphasises the wisdom of precautions if these are to be conserved and enabled to continue to coevolve.

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Habitat Change

Massive physical land-use transformations, largely involving clearance of vegetation and its replacement with improved pasture, agricultural and other crops and plantations, urban and industrial developments and the associated multitude of subsidiary processes and impacts, together with the draining and filling-in of waterbodies, have embraced all significant insect habitats throughout the anthropogenic world. The traditional concept of ‘a habitat’ as ‘a place to live’ has led to designations or implications of numerous moths as inhabitants of particular biomes, sometimes to indicate where they mainly occur—but without more detailed biological confirmation. Categories such as ‘forest moths’, ‘grassland moths’, ‘heathland moths’, ‘wetland moths’ and many others are thus valuable initial descriptors, which are easily augmented by geographical terms such as ‘tropical’, ‘temperate’, ‘alpine’ and ‘coastal’ (and others) to further inform the characteristic environments to which many species are largely restricted. Such broad ecological categorisations can reliably suggest major ecological habitat categories and their related moth communities. Any such descriptor is far more complex than initially indicated, and further description involves progressively increasing numbers and subtleties of features that enable their distinctiveness to be recognised—for example by the floristic components on which a particular species may depend, with loss of larval food plants being a critical threat to many herbivores. The somewhat different approach of ‘resource-based habitat’ advanced by Dennis et al. (2006, and discussed extensively by Dennis 2010), and drawing from the ecological arrangement listed by Shreeve et al. (2001), is highly relevant in clarifying environmental features for insect conservation, in focusing on the critical resources that a species needs for survival. Rather than ‘just a place’, a habitat then becomes appreciated as a situation in which a species’ critical resource needs are available and accessible and where those resources may vary and determine both carrying capacity and whether that species can indeed survive there. Resource needs for larvae and adult moths clearly differ and must be assessed separately for the two stages, which are essentially very different insects with different feeding habits and needs. The most obvious resources, forming the foundation of many conservation management plans, are ‘consumables’, larval food plants, adult floral resources and any other foods needed, each of which may be very specific. More difficult to define fully and evaluate ‘utilities’ embrace the environmental features that allow a species to utilise consumables and thrive in its environment. As examples, these might include specific oviposition or pupation sites, bare ground for insolation or display, mating foci, territorial markers, refuges from natural enemies and aestivation or hibernation sites. These might or might not occur in the same places as consumables and may necessitate movements into the areas around food plant patches. Their variety emphasises the relevance of landscape-level assessments and how resources are distributed locally. With far more evidence for butterflies than for moths, metapopulation structures reflect the dispersion of resources in relatively discrete patches that can be colonised and within each of which critical resources may vary

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over time so that each patch varies in its suitability to sustain a population. Patch size is an important consideration, and erosion of habitat is often accompanied by fragmentation, whereby previously larger habitable patches are broken and replaced by remnant smaller areas. Both resource quantity and resource quality are relevant, and larger patches may provide a quantity sufficient to offset some loss of quality. Understanding moth biology for conservation necessitates recognition that a moth’s ‘habitat landscape’ involves a dynamic pattern of resources that are changing continually in time and space. Access to resources may also be influenced by local microclimate, notably temperature regimes, that has sometimes been referred to as a separate category of resources, as a ‘conditioner’. Even for the best-known Lepidoptera such as British butterflies, for which enormous amounts of information are available, full documentation of resource issues and their dynamics is incomplete, but the synthesis by Dennis (2020) demonstrates the complexities of interpreting many aspects of butterfly ecology. For both butterflies and moths, evaluating sites (whether considered as ‘habitats’ or ‘patches’) for resource supply and suitability for the target insect is a critical foundation in conservation planning. Emphasis on resources helps to recognise that ‘habitat loss’ occurs at various scales—whereas clearing of forest is very obvious, small floristic changes affecting (for example) light penetration, food availability or ease of insect movements may each affect or disrupt the species involved and influence interactions within its host community and are far more difficult to evaluate or detect. Many such influences and ‘subtle’ habitat changes are inevitably overlooked, but they also suggest that, even though a forest or native grassland still exists, less obvious intrusions can greatly alter its suitability for specialised insect inhabitants. Nevertheless, and despite the paucity of ecological detail, the ecological requirements of many moths can indeed be validly categorised (as above) by major land cover or vegetation type as ‘classical’ habitat forms. Thus, for the ‘macromoths’ (excluding Geometridae and Noctuidae) of several central European countries, five major habitat association groups could be recognised, each with several consistent biological correlates. These comprised analysis of resource use by 164 species, as described by 178 life history conditions (Pavlikova and Konvicka 2012) (Table 4.1) from which ordination analysis grouped the species by their habitat use. Three of the five groups (closed canopy, open canopy and grassland) reflected habitat structure rather than any moth phylogeny, whilst the other two groups (herb-feeding hawk moths and lichen feeders) had strong phylogenetic linkages, with the hawk moths also showing some habitat effects. A revealing trend from this study was the importance of vegetation structure rather than strict host plant specificity. Many of the canopy species, for example, frequented the same tree species in both habitat forms. Major habitat changes due to human activity are a universal and predominant concern for the future of much of earth’s biodiversity. However, Fox (2013) commented that ‘There is little direct (my emphasis: TRN) evidence of habitat loss, degradation or fragmentation effects on moth populations in Britain (or elsewhere)’, but also that there is ‘considerable circumstantial evidence’ that habitat degradation has had severe impacts on specialist moths, with the implication

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Table 4.1 Ecological classification of macromoths of central Europe: major habitat associations; classification based on the matrix of 178 life history attributes describing resource uses by 164 moth species. Groups IV and V are taxonomically restricted; others contain a wider array of taxa (Pavlikova and Konvicka 2012) Association group I. Close canopy moths

II. Open canopy moths III. Grassland moths IV. Herb-feeding hawk moths V. Lichen feeders

Comment Species with larvae developing on woody plants, mainly trees and mainly in the canopy; tend to have small egg batches, larvae not hairy and pupae overwinter; 53 species Species developing on woody plants, often shrubs (often Rosaceae or Salicaceae); tend to oviposit in batches, have hairy larvae and do not consume nectar as adults; 47 species Species developing on herbs and grasses; oviposit in large batches, often polyphagous and hibernate on ground surface; 39 species Species with larvae feeding on herbs, overwintering as pupae and feeding on nectar as adults; some are long-distance migrants; 14 species of Sphingidae Species feeding on lichens, with univoltine development and overwintering larvae; 21 species of Erebidae: Arctiinae

of roles in moth declines and losses of species. Fragmentation impacts may be less than from habitat loss and degradation, depending on the mobility of the taxa considered. Life history traits associated with dispersal, reproductive potential and extent of ecological specialisation collectively influence how (and if) a species persists in a fragmented landscape. Immigration from other populations and recolonisation following losses—in many taxa reflecting a metapopulation structure—may be affected by decreasing habitat patch size and connectivity across the landscape, together rendering each habitat patch more isolated. Higher species richness tends to occur on larger sites and those with greater connectivity (Ockinger et al. 2010). Conversely, fragmentation may be more threatening for specialised species with only low mobility (Thomas 2000). Landscape homogenisation, as in cultivated landscapes, is associated with losses of less mobile moths (Ekroos et al. 2010), and a key to conserving these and habitat specialists is to increase habitat availability and connectivity. Moths in Britain may have been affected substantially by the destruction of seminatural habitats up to around the mid-twentieth century, with much of the more recent conservation focusing on aspects such as (1) reducing the intensity of agricultural management, including attention to field margins, and (2) reinstating traditional management of broad-leaved woodlands, both of which are associated with moth richness and abundance on the landscapes involved (Fox 2013). The longterm information on which such management can be soundly based is largely absent beyond Europe, but the general needs to preserve, enhance or restore naturalness and heterogeneity are universal. The complexities of the interactive effects of habitat changes and climate change lead to many interpretative difficulties. Monitoring of moths by light traps over 23 years in Prague, Czech Republic (for a total of 424 macromoth species and 800,690 individuals), revealed several ‘habitat groups’, with various species

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characteristic of particular circumstances, namely early successional arable land (25 species), forest species feeding on shrubs and trees (116), forest species feeding on herbs/lichens (33), forest steppe species (92), grassland species (116), wetlands (28) and non-specialised generalists (14 species) (Kadlec et al. 2009). Changes in composition implied that habitat specialist species responded predominantly to landuse changes, with declines in all groups associated with habitat changes within the range of the monitoring trap. Those changes included the loss of small arable areas to urban development to leave only small grassland patches, as occurred also within forest steppe areas. These and other gradual changes in habitat were reflected in moths. The slowest apparent changes were for grassland species and those of the forest understorey. The number and diversity of generalists increased over time, reflecting that these are mostly polyphagous species able to locate suitable food plants from the range of candidates present. Kadlec et al. suggested that the richness of generalists, in contrast to specialists, is more related to long-term meteorological trends, notably of increased temperatures favouring their ability to find suitable hosts as others decline locally. The importance of successional grasslands as habitats for moths and butterflies in Europe has for long been recognised, with numerous species having declined as those grasslands disappear or are changed. Calcareous grasslands support many Lepidoptera not found elsewhere and are a prime focus for butterfly conservation. However, in addition to anthropogenic disturbances, succession may both (1) cause extinctions/extirpations of local grassland species as their habitat is lost and (2) increase species richness through the diversification of local habitats (Habel et al. 2019a). From 1987–2017, 1016 moth species were found in calcareous grasslands near Regensburg, Germany. Over that period, the succession markedly changed the grassland environment to a mosaic of stony slopes, forests and shrubs, with grassland reduced to patches. A comparison of the moth species present before and after 2000 (Habel et al. 2019a) showed that (1) 122 species were lost, most of them specialists associated with semi-natural calcareous grassland, and (2) 411 species were recorded only in the later period, and most of these were associated with later successional stages such as tall herb and shrub/forest habitats. A few of these ‘arrivals’ may have been overlooked in earlier surveys as members of sibling groups then not fully diagnosed (11 species) and 22 species had expanded their range more widely in recent years. High diversity of ‘new’ species associated with shrubs, as an intermediate successional stage, was accompanied by the loss of earlier grassland specialists, and Habel et al. noted the likely future of more uniform treed vegetation in which meadows and other grasslands were largely absent and their characteristic species thereby excluded. Most of the losses were indeed of species highly characteristic of the grasslands. The converse process, of restoring calcareous grassland by removing forest vegetation, creates the situation that resources for forest moths are lost, whilst the cleared areas have not yet developed the characteristics suitable for grassland specialists—so losses are accompanied by lack of colonisation (Rakosy and Schmitt 2011). That study, however, was for only 2002–2004, a period that (as the authors

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noted) was probably not long enough for any balance to be reached. Nevertheless, butterflies were much more responsive than moths during that study and may be the better indicator group for monitoring such changes. The many specialist insect species that frequent grasslands and other open habitats maintained traditionally by low-intensity agricultural practices in Europe have collectively undergone large-scale declines in abundance. Many of the declines, however, are relatively local. As Habel et al. (2019b) pointed out, widespread extinctions are rare but more local disappearances (‘extirpations’) and reduced abundance are more common and typically with the more generalist species better able to cope with rapid changes to their living conditions and declines amongst the more ecologically demanding taxa. Both local and wider landscape conditions influence moth assemblages in small islands of semi-natural grasslands or other open areas such as clear-cuts in agricultural or forest landscapes, so that diversification of the habitat elements present is beneficial in enhancing heterogeneity as a foundation for increased moth diversity (Samu et al. 2016). Small habitat islands may derive from management practices. Clear-cuts in forests may become important temporary habitats, as areas with herbaceous vegetation and nectar sources, but as transient components of the landscape matrix. Bergman et al. (2020) demonstrated that clearcuts in Swedish forests can support breeding populations of several rare Zygaenidae, including red-listed species. However, clear-cuts last for only about a decade before shading increases, so the food needs for these moths then decline. Suitability can be prolonged by management, but more generally their conservation values in forests depend on repeated colonisations as they become available and, hence, on wider landscape connectivity. Clear-cut areas in a Japanese larch (Larix kaempferi) plantation in South Korea, although considerably less rich in moths than uncut forest (84 cf. 199 species), had higher relative numbers and richness of herb-feeding and warm-adapted species, with a higher component of Noctuidae (Moon et al. 2018). Land-use intensity (LUI) is a key conservation focus in assessing agricultural impacts, and the variety of trends accentuates the variety across different moth species. General components of LUI are grazing intensity (stocking rate, timing, grazer species), mowing or slashing (seasonality, frequency and height) and the amounts and kinds of fertiliser applied. Impacts were shown through significantly reduced abundance and richness of moths on a series of sites across Germany, over which more than a quarter of the 178 species (of a total of 461 species present) representing those typical for grassland habitats showed negative responses to LUI (Mangels et al. 2017). However, separating the effects of the three management components (grazing, mowing, fertiliser application) gave many combinations of responses: an overall ‘winner’ may be a ‘loser’ or ‘neutral’ to any of these, and grazing/mowing may have opposing influences. As one example, the tortricid Chrysoteuchia culmella was overall assessed as ‘neutral’ but showed more focused appraisals of ‘loser’ (grazing), ‘winner’ (mowing) and ‘neutral’ (fertiliser). The most widespread trend found was a community shift towards more generalist species as LUI increased. Mowing, as a major disturbance, can cause substantial mortality of larvae, with consequent impacts on adult population size, and changing floristic

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composition (either by the destruction of rare species or selective enhancement through fertiliser applications) either disadvantage or benefit specialist moth taxa. Management of any LUI component strongly influences the suitability of grassland for moths (and other insects), and in the absence of more detailed knowledge, some form of ‘mosaic management’ may help to conserve the greatest diversity. Thus, for a grassland reserve in the Czech Republic the moths found on sections that were mown or abandoned temporarily showed different trends (Sumpich and Konvicka 2012). In a survey that unusually assessed both macrolepidoptera (215 species) and microlepidoptera (157 species) at the species level: (1) many grassland specialist macrolepidoptera either preferred unmown sections or showed no preference and (2) grassland specialist microlepidoptera were equally represented across these regimes. The survey also confirmed that mown areas could continue to support significant species. General trends of impacts of site changes on grassland moth assemblages are exemplified by comments on the diverse endemic tussock grassland moths of New Zealand (White 1991, 2002), where site changes were correlated clearly with changes in the moth fauna. Thus, at one site, on which herb loss was linked with a doubling of grass cover over 26 years, the abundance of herb-feeding and grassfeeding moths declined by 88% and 74%, respectively, whilst greater floristic diversity on another site was associated with far lower declines. On both sites, common moths were amongst the most marked declines. White (1991) found four trends relevant to considering conservation management of tussock grasslands for moths: (1) vegetation changes, including invasions by Agrostis, directly modified the endemic moth fauna; (2) those changes were accelerated by more intensive pastoralism; (3) the more abundant moth species were often those first affected by changing vegetation composition when invasive species disrupted native flora; and (4) increasing scarcity of some endemic food plants, especially herbs, implied species losses amongst the local moth fauna. The impacts of grazing may be important for moth conservation by maintaining an open sward and preventing sensitive native flora from becoming overgrown. Forest clearance, especially in the tropics, is regarded by many people as the most notorious global land-use change and that of greatest concern as the direct and continuing loss of environments that are acknowledged widely to support vast numbers of insects and other biota, mostly not known anywhere else. Especially in the Neotropics and south-east Asia, unique forest environments are being lost for timber extraction, oil palm plantations (p. 100) and simply clearing to open up land for grazing or other human use. Their insect inhabitants are largely undescribed, and many species are unknown, but it is clear that moths are (or have been) diverse components and—not surprisingly—are sensitive to their habitat loss. ‘Selective logging’ (viewed by many foresters as the intensification of the natural pattern of the tree falls that create forest gaps throughout tropical forests and for long the principal disturbance to forest in south-east Asia: Willott 1999) is also widespread, but the main outcome of forest exploitation, as for grasslands, is simplification through loss of vegetation and reduction in vast areas of unbroken forest to small and progressively isolated remnant patches that are increasingly subject to a variety of edge

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effects and further erosion of quality. Preserving or re-constituting functional linkages (‘connectivity’) between remnant habitat patches is a central consideration in conservation management and can occur through linear strips of protected or restored habitat (‘corridors’) that link larger remnant or pristine patches, or small intermittent patches (‘stepping stones’), in principle facilitating movements of moths or others across the otherwise inhospitable landscape. Whether such measures are effective is often uncertain or unproven. Large-scale transformations of tropical forest in south-east Asia for oil palm plantations now incorporate strips of riparian forest along water courses, with the initial purpose of reducing run-off into streams but now required formally with wider conservation roles as putative movement corridors and less intensively disturbed habitat. Riparian strips have a minimum width of 30–100 m on both sides of a river depending on the river width and other factors and can become important refuge habitats. Mark–release–recapture study of several large common Erebidae in Sabah (East Malaysia) suggests that such riparian strips can indeed function as corridors for moths (Gray et al. 2019). Larval food plants of the species studied were absent in the oil palm plantations, and some moths recaptured in the plantations were perhaps ‘stragglers’ as foraging individuals attracted to the fermenting banana baits used to sample the moths. Subtleties of influence of forest fragmentation are illustrated through an important moth defoliator of deciduous forest trees throughout North America. The Forest tent caterpillar (Malacosoma disstria, Lasiocampidae) undergoes cyclical outbreaks that can last 1–8 years and are believed widely to be suppressed by actions of natural enemies. Variations in outbreak persistence partially reflect the attacks of a number of parasitoid Hymenoptera and Diptera, most of which have a far broader host range of forest Lepidoptera (Schmidt and Roland 2006). The abundance of most parasitoid species decreased with forest fragmentation, and the decreased availability of most host moth species in fragmented forests may exacerbate outbreaks of M. disstria. Outbreaks may persist for several years longer in forests fragmented by forestry or agriculture than in the continuous forest. At high M. disstria local densities, fragmentation reduced the impact of parasitoids and viral pathogens. Many of the hosts are arboreal-feeding moths, which were more sensitive to fragmentation than non-arboreal species (Schmidt and Roland 2006)—but this is not always shown by simple overall species richness, but revealed only when such guilds are distinguished, because losses of arboreal species may be compensated by the influx of other species from the wider landscape. Although host ranges were not fully known in this study, it was inferred that alternative hosts were most likely to be a subset of the co-occurring arboreal taxa. Fragmentation and loss of hosts also diminished parasitoid populations, again implying higher generalist parasitoid density in continuous forest. Such studies on forest moth population dynamics are restricted largely to major pest species, and the ramifications for wider moth communities have been studied only rarely (Summerville and Crist 2008). Edge effects may influence even protected forest patches as the intervening matrix is progressively changed—so that forest-dependent sphingids and saturniids have both declined substantially in some Ugandan protected forests in the last few decades (Akite et al. 2015). Characters of the inter-forest matrix may variously

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support or alienate the residence of native forest moths, so that many species may be able to utilise both habitat areas and also move between them. This can lead to the surrounds of forest fragments yielding high moth richness and abundance, referred to by Ricketts et al. (2001) as the ‘halo effect’ and within which assemblages may not differ markedly from those within the forest. In their study in Costa Rica, the halo effect was believed to extend between 1 and 3.5 km from the forest edge, but was influenced by local conditions that affect the ability of different species to survive in the changed matrix. In general, the boundaries between forests and adjacent cleared areas or other habitats are strong ecotones—transition zones with some unique resources and residual properties of both bordering ecosystems and that may support both higher insect richness than either of these as well as species not typical of either, as restricted to the ecotone. In boreal forests of eastern Canada, light-trapping moths in these ecotones implied higher moth richness than in either forest or clear-felled areas (Pinksen et al. 2021), so forestry operations created unique moth assemblages. Moth abundance was higher than in clear-cuts but not in forests, and most moth species were indeed found in all three treatments. Forestry practices that could render such borders less abrupt may benefit moth diversity in these boreal forests—as elsewhere—and Pinksen et al. suggested that management could incorporate deliberate ‘softening’ of edges in conjunction with varied disturbance regimes. The gradients of disturbance between forest fragments and deforested matrix can be abrupt, gradual or manifest little change in the moth assemblages at different points. Using large amounts of data on moth catches from the contrasting tropical forests of Mount Kinabalu National Park (Borneo) and Podocarpus National Park (Ecuador), Fiedler et al. (2007) found that local species diversity did not always decline—and could even increase—along such gradients. Differences occurred between taxa. Sphingidae and Arctiinae were equally rich in forest and through the forest edge, whilst both Geometridae and Pyraloidea declined. Most species occurred on both sides of the forest edge, but in different abundances and with implied sensitivity to environmental changes at small spatial scales. Geometridae, for example, became considerably impoverished only a few dozen metres from natural forests, whereas this was never so for Arctiinae. The lesson that changes in moth assemblages can predominantly involve changes in the relative abundance of species rather than of species composition poses considerable problems for interpretation. However, Fiedler et al. implied that forest margin moth assemblages (1) were not simple subsets of the forest fauna and (2) did not mainly comprise common ‘weedy’ non-forest species. Their species reflect both of these habitat conditions within the mosaic of forest margin gradients. The transitions and varying heterogeneity at forest margins—where they meet, for example, secondary forest, farmland, abandoned pastures, villages and/or a variety of other transformed regimes—make predictions of moth assemblage change inconsistent and difficult to predict beyond supposed generalities. In northern Borneo, many native habitat moth species were not restricted closely to the primary forest and were resistant to habitat disturbance. Treefall gaps may be important providers of open larval habitats. Schultze and Fiedler (2003) suggested that a ‘substantial proportion’ of Bornean

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Sphingidae has benefited from forest clearing and recently created secondary habitats—as long as those have not progressed to large-scale monocultures such as oil palm plantations. Such nocturnal hawk moths were regarded here as ‘an exceptional insect group’ because many species were adapted to such changed mosaic environments. In a wider consideration of south-east Asian sphingids, Beck et al. (2006) noted the different responses to disturbance by many Smerinthinae (capital breeders that declined from forests towards highly disturbed sites) and diurnal Macroglossinae (income breeders, showing the reverse trend and probably well adapted to thrive in early successional disturbed habitats). The differing responses of moth groups to forest disturbance is the foundation of selecting potential taxa as putative indicators or predictors of habitat quality and its links with disturbance levels (p. 90), but that selection depends on adequate surveys to provide confidence in the information available. As Kitching et al. (2000) commented in studies on the Atherton Tablelands of tropical Queensland, ‘moth assemblages are powerful indicators of forest disturbance’. As elsewhere, confirmation that even severely disturbed forest remnants can continue to harbour substantial regional moth diversity and thus retain significant conservation value, with greatest values for patches with vegetation most closely resembling the parental composition, has flowed from this and parallel studies. The relative representation of selected moth taxa in three categories of notophyll vine forest remnants demonstrated a variety of abundance patterns (Fig. 4.1). Data were from three remnants each that were (1) never cleared, (2) secondary sites with substantial regrowth and (3) newly cleared (‘scrambler land’) with many alien weedy species and some native weeds. As elsewhere (see Chap. 2), many moth species favouring disturbed sites were polyphagous on a range of early successional plants. Throughout, wet season catches of the target groups were higher than dry season catches. Natural succession from cleared forests to produce ‘secondary forest’ is an attractive ‘leave alone strategy’ in conservation and gives those forests considerable conservation importance as they accumulate regional insect and other species. However, the new diversity may not be equivalent to the original, even after several decades. Surveys of geometrid moth assemblages in China compared their representation in a remaining protected forest and forests allowed to regenerate naturally from clear-felling for about 50 years (Zou et al. 2016). The secondary forest supported similar geometrid richness and taxonomic diversity, but with substantially different species composition to that in the native forest. Species overlap between the sites was only about 30%, but the survey confirmed that regenerated secondary forest could be a significant habitat for moth conservation in a disturbed landscape. Several comparisons of moths across paired sites (natural and disturbed by forestry operations) have demonstrated differences related to the treatment received. Comparison of Geometridae and related families across paired primary forest and logged secondary forest sites in Malaysia (Intachat et al. 1999) showed that species richness was rather similar, but that species assemblage composition shifted. Many species were unique to one or other forest type (primary 142, secondary 108), with 180 species found in both. Abundances were generally higher in the primary forest samples, but there was some suggestion that the higher number of unique species in

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Fig. 4.1 Abundance and seasonal differences (black bars, wet season; open bars, dry season) in moth individuals for selected taxa captured in forest remnants of three categories (U: uncleared, R: regrowth, S: scrambler [see text]) on the Atherton Tablelands of Queensland (a, Geometridae, Ennominae; b, Lymantriidae; c, Noctuidae, Amphipyrinae; d, Arctiidae, Arctiinae) (after Kitching et al. 2000, with their nomenclature)

the primary forest might reflect the loss of some of these putative specialist species vulnerable to the disturbance incurred. Intensive forestry tends to reduce early seral stages, in efforts to reduce plant competition with the crop trees. In Oregon forests, management that retained patches with early successional vegetation was most likely to benefit moth conservation (Root et al. 2017), with moth species richness related strongly to plant species richness. In Sabah, Malaysia, logged forest understorey was overall less rich in moth species than the primary forest understorey, but the primary forest canopy gave higher richness than understorey samples alone (Willott 1999). Impacts of logging could be appraised by the representation of two moth groups: (1) those restricted to primary forest and so did not persist in logged forests and (2) those found only in logged forest and presumed to be invaders after disturbance. Of a species pool of 1238 species, more than half (55%) were restricted to primary forest and only 11% to the logged forest. However, only 55 species (40% of individuals) of a single species from each group, and assemblage compositions differed considerably, with at least 2/3 of the species found in forests absent from plantations and most plantation species occurring in very low numbers. As in many such contexts, the wider ecological consequences of such faunistic changes remain unknown. Long-isolated island faunas, including Australian biota, are particularly susceptible receptor environments for introduced or other alien species. The size and geographical variety of Australia add the parameter that species moving or transferred from one part of the continent to another may also be considered ‘non-native’ because of their novel (locally non-native) status up to several thousand km from their natural range. These parallel conditions for alien moths in Europe, for which Lopez-Vaamonde et al. (2010) distinguished the two categories of naturalised exotic species originating from continents other than Europe and whose introduction appears to be from human activity, and European species spreading throughout the continent from human activity. The first of these included species with known origin, termed ‘cryptogenic’, but even for many of the species with a clear geographical origin, the mode of arrival may still be uncertain, as elsewhere in the world. The Palaearctic Poison hemlock moth, Agonopterix alstroemeriana (Depressariidae), appears to be extending its range in the Southern Hemisphere and has recently (from 2016) been recorded in Tasmania. Although it may have arrived from New Zealand (where it was established in 1986), this is difficult to confirm (Chen et al. 2020). It is monophagous on the introduced weed Conium maculatum (Apiaceae), and its confirmation in Tasmania flowed from citizen science observations. In Europe, many alien moths are associated with the importation of food plants or stored products. Many are also confined to anthropogenic habitats (such as parks, gardens and crops), and, as in Australia, alien moths are not diverse in many natural vegetation systems. Dynamic patterns of the natural movement of animals and plants are augmented by human transport, and the function of Australia’s strong biosecurity/quarantine laws is to prevent the arrival of further damaging biota from elsewhere in the world, together with their parasites and diseases that could affect the native species. The global history of classical biological control, whereby natural enemies of a pest are

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introduced and allowed to establish in areas now occupied by the pest, includes many suggestions and implications of non-target impacts on native species as parasitoids and predators spread into more natural environments. Some moth extinctions in Hawaii, for example, are linked strongly with this cause (Howarth 1991). Formal host specificity tests are part of modern pre-introduction risk assessment for any such agent proposed for introduction, with the aim of minimising undesirable non-target impacts through sound risk/benefit analysis. For weed control, tests involve a range of plant species, including any native relatives of the introduced target species, and evidence of acceptability of native (or other ‘desirable’) flora may preclude releases of the potential agent. However, each case is evaluated individually. Two species of geometrid moths from Kenya were screened for introduction to control Prickly acacia (Acacia nilotica), regarded as one of the worst woody weeds in northern Australia (Palmer et al. 2007). Tests for larval feeding and development on 74 plant species in quarantine conditions in Australia revealed that both Chiasmia inconspicua and Chiasmia assimilis could survive and develop in small numbers on a few native Acacia species. Such risks were deemed low, and multiple introductions of both moths were allowed, initially with no evidence of establishment. A later release of C. assimilis from South Africa into a climatically more suitable coastal area led to the establishment. However, any such release—however, rigorous the pre-release screening—may have unanticipated consequences as a novel species reaches a new environment. The consequences of exposure to more generalist species are exemplified through the introduction of a European parasitoid fly, Compsilura concinnata (Tachinidae), to eastern North America over much of the twentieth century as a biological control agent to suppress a major forestry pest, the Gypsy moth, Lymantria dispar (Erebidae: Lymantriinae). The multivoltine fly depends on additional, native, hosts for overwintering and has been reported as an ‘extreme generalist’ known to attack around 200 non-target hosts spanning many families of Lepidoptera in the region— as well as some sawflies (Hymenoptera). Attention was drawn to its significance in conservation by implication that Compsilura contributed to substantial declines of native Saturniidae in New England (Boettner et al. 2000), together with other factors such as habitat loss, outdoor lighting and pesticide sprays. Field trials, involving exposure of larvae of the Cecropia moth (Hyalophora cecropia) and Promethea moth (Callosamia promethea) for periods and rearing them in the laboratory, recorded high levels of parasitisation. A later trial, using a similar approach, revealed high attack levels also in the Moon moth, Actias luna (Kellogg et al. 2003). The latter authors considered that the fly ‘has the potential to alter the population dynamics of many saturniid moths’ in the region—and by extrapolation, it might affect other host species. High levels of hyperparasitoidisation by trigonalid wasps may have restricted the growth of the fly population. The species mentioned above are part of a much wider decline of native saturniids in the region, which has led to increased conservation significance of several species: Baranowski et al. (2019) cited the Regal moth (Citheronia regalis) as extirpated from the New England mainland, and both the Imperial moth (Eacles imperialis) and the Barrens buck moth (Hemileuca lucina)

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Fig. 5.3 Spread of an invasive moth species: the changing distribution of Brown-tail moth, Euproctis chrysorrhoea, across New England, United States, indicating rapid expansion and later contraction to coastal sand dune habitats (after Elkinton et al. 2006)

are of concern in Massachusetts—with the control efforts for Gypsy moth a possible contributor to these declines. However, repetition of Boettner et al.’s field exposure trials, using the same two host species, in 2017 and 2018 revealed only very low levels of Compsilura attack (Baranowski et al. 2019). The reasons for this are unclear, but in some areas (such as some New England islands: Goldstein et al. 2015) the fly seems to have become rare. One possible contributor is the Entomophaga fungus also used from the late 1980s as a further biological control agent. This acts very rapidly, so that any parasitoids in fungus-affected hosts cannot complete development and are also killed. Nevertheless, the primary efficacy of Compsilura as a biological control agent is illustrated also by its impact on another introduced forest pest moth, the Brown-tail moth (Euproctis chrysorrhoea, also Lymantriinae). It appears to have been instrumental in what Elkinton et al. (2006) referred to as the ‘enigmatic near extirpation’ of this highly invasive pest. Figure 5.3 illustrates the moth’s reduced distribution over 1914–1922, with only isolated infestations in coastal Cape Cod (south-east of map) by 2001. High-density Brown-tail moth populations persisted in sparsely vegetated dune areas where tachinid mortality was low, possibly reflecting a lack of alternative hosts in these areas of low plant diversity, exacerbated by lack of nectar supply for adult flies and exposure to salt spray. Whilst major practical benefits can indeed result from such use of generalist control agents, this does not obviate the non-target harm to native species that can easily elude notice—and is rarely sought deliberately or comprehensively after an agent is introduced and may not be noticed until effects become severe. Practitioners have urged widely that such introductions are unwise and should not be made (Elkinton and Boettner 2012, on Compsilura).

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Fig. 5.4 Numbers of native Lepidoptera species on all plant genera and on native and introduced woody plant genera used as ornamentals. Data from the mid-Atlantic states of the United States (from Tallamy and Shropshire 2009)

The focus here is on non-native plants and insects relevant to Australia’s moths: in part, this limitation must be placed in the context that most of Australia’s agricultural economy is based on non-native species, from cattle and sheep to the wide range of food and commodity crops. Pasture grasses from Africa and elsewhere, pine trees from North America and numerous crop and ornamental plant species have long been predominant features of Australian landscapes and ecology, irrespective of any functional changes they confer. In turn, any such plants may become food for native or alien insects, many of them innocuous but others being or becoming serious pests that demand suppression. The full extent of such host range expansions or host transfers amongst Australian moths is unknown. However, an overview of Lepidoptera use of native and introduced plants for part of the United States suggests how this study might be approached. Tallamy and Shropshire (2009) ranked all native plant genera by the number of Lepidoptera species reported in the published literature as using them as hosts. They also compared introduced versus native plant genera used as woody landscape plants, introduced versus native woody and herbaceous genera whether or not used as ornamentals and woody versus herbaceous native plants, adopting the perspective that moths and butterflies are valid surrogates for all insect herbivores. Two important findings are summarised in Fig. 5.4; the number of species recorded from introduced plant genera is smaller than on native host genera, and the difference between the two categories of woody ornamentals is large and included several introduced moth species. Together, woody plants supported about tenfold more species than herbaceous plants. Such an analysis for Australia is still premature, but relevant data are increasing. As noted earlier, the full host range for most Australian moths is unclear. It is readily accepted that some species, perhaps many, feed only or largely on particular plant taxa such as Acacia or Eucalyptus but the more restricted host ranges within these (and other

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large endemic genera) are far less known. However, much of the highly endemic Australian flora may be phylogenetically relatively difficult for alien moths to access, with the reverse transfer of native moths to introduced flora perhaps ‘easier’ to achieve. Most introduced plants in Australia have been available for well under 200 years, and host shifts over that period are considered largely opportunistic, and their future extent is uncertain. Paralleling the US situation noted above, it seems likely that most species will continue to depend on native host plants, and moth diversity depends on the maintenance of native flora. Tallamy and Shropshire recommended that landscapers in the United States should use native woody plants over introduced species as a measure to sustain moth diversity. An overview of 76 studies that provided comparative data on Lepidoptera richness and ‘performance’ (usually measured as larval weight) on native and alien plants implied that survival and performance were reduced on alien plants (Yoon and Read 2016). In some instances, survival was very low and the alien plants essentially became ‘ecological traps’ (as well known in Australia for the Richmond birdwing butterfly, Ornithoptera richmondia: Sands and New 2013). Yoon and Read suggested the general case of alien plant invasions decreasing Lepidoptera richness and abundance as high-quality native hosts are diminished, leading to reduced moth community richness, so alien plants should preferably be removed. In Australia, as elsewhere, the long-term consequences of such host shifts as novel food plants become available remain unclear. However, as it appears for some populations of Golden sun-moth (p. 162), such aliens may be the only (or the largely predominant) food available on highly modified grassland sites and, as the only food present it may become important to retain them. Australian eucalypts have been planted extensively elsewhere as a source of plantation timber and may then be exploited by native moths. Assessing the diversity of moths in eucalypt plantations generally involves light-trap catches without any clear evidence of association or interdependence. Comparative catches of Arctiidae (now Erebidae: Arctiinae), Sphingidae and Saturniidae in primary forest, secondary forest and plantations of Eucalyptus urograndis in the northern Amazonia region of Brazil yielded a collective 335 species (Hawes et al. 2009) in a complex habitat mosaic of these three categories, in which sampled blocks were large (Eucalyptus mean size 1687 ha; secondary forest mean size 2682 ha) and well separated (mean distance between the 15 blocks of 30 km). Three patterns were implied: (1) moths in individual primary forest blocks were not collectively richer or more diverse than others, but each of the three forest types had distinct moth communities in terms of structure and composition; (2) species turnover was highest between primary forest and Eucalyptus plantations, with secondary forest intermediate; and (3) the three selected moth families varied in richness in response to disturbance, but changes in abundance and community structure were relatively constant. The more generally accepted inference of adverse impacts of plantation forestry on biodiversity was supported by the different responses of the three families, with higher richness in the two disturbed forest categories attributed to landscape heterogeneity. Also in Brazil, the moths appraised along a transect from the residual native forest across the intervening edge and at intervals into an intergrading plantation of Eucalyptus

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grandis and Eucalyptus saligna yielded 790 morphospecies (all of ‘larger’ moths, with those of body length 1.7 m/s suppressed catches of both, the optimal temperature for captures was 27 °C and bright moonlight reduced numbers of H. armigera by about half but did not influence H. punctigera. From that information, trapping should occur on warm still nights, but not around the full moon period for H. armigera. Flight periodicity may also occur—many moths characteristically fly only at particular times of the night. The major concern for conservation, however, is the proliferation of artificial lighting at night, most notably in and around urban areas but with street lighting and others ensuring that effects are far more varied and continue to become more widespread. ALAN is reported to be increasing at an average of about 6% per year, mostly from urbanisation (Peters et al. 2020) and is regarded as a major threat to nocturnal insect biodiversity through disturbing all aspects of their life cycles and behaviour. The most frequently implied impact is simply that concentrating moths locally in response to light both removes them from the wider environment and provides a concentrated accessible food supply for bats, birds and other insectivores, so becoming a population sink. However, as Boyes et al. (2021a) found in a widespread review, effects are far more varied and extend across different life stages. The severity of ALAN-related impacts on nocturnal moths reflects local species composition and the local light environment, with effects clearly both complex and variable across taxa. Two ALAN-related impacts contribute in particular to the declines of moth populations. Predation rate on moths can be higher near light sources to which both predators and prey are attracted, with ALAN also hindering normal moth defensive behaviour and increasing their susceptibility. Prolonged photoperiods from ALAN may increase predator foraging periods. For example, attracted adults can become inactive and ‘rest’ for the remainder of the night, so affecting activity related to feeding, mating and continuing movements—including migrations. One inference from that overview was that very limited evidence actually exists for ALAN exerting negative effects on moth populations and that some studies attributing losses to this effect may be premature in not having clarified the role of ALAN in the context of other co-occurring drivers of decline. Thus, the complex effects of urbanisation may confound easy interpretation, and the overall impacts have rarely been quantified. Peters et al. (2020) cited an earlier estimate of 1011 moth deaths at light sources in Germany during a single summer and such vast figures are a sobering suggestion of the possible extent of losses on local faunas elsewhere. Increased use of LED lights, which do not emit ultraviolet light and may attract far fewer insects than more conventional ALAN sources (Wakefield et al. 2016), may be a significant countermeasure although this is not always so (Boyes et al. 2021b). Nevertheless, the impacts of ALAN on moth faunas can become very difficult to interpret. In urban areas, ALAN can reduce the efficiency of light-trapping used to evaluate moth abundance and species incidence in relation to the common survey practice of comparing trap catches in paired urban and rural sites. This can create a

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Table 5.4 Potential effects of anthropogenic light on moths, indicating the variety of mechanisms and life history stages that can be affected (after Boyes et al. 2021a, based on their Fig. 4) Mechanism Perceived as daylight

Elicits phototaxis Perceived as or masks celestial light Direct damage/prevention of dark repair

Stages and impacts Suppress activity: flight (adult), feeding (adult, larva?), reproduction (adult); disrupt circadian processes: reproduction (adult), hatching/emergence (ova?, pupa?); prevent detection of seasonality; diapause/no-diapause (larva); mistime emergence (pupa) Adult: distracted/loss of time, direct mortality, dispersal restricted, increased predation Adult: long-distance navigation impeded Any stages

hard-to-measure sampling artefact by leading to reduced catches, with the interpretation of the ‘real difference’ and ‘sampling effect difference’ usually a matter of conjecture—or being ignored completely. Some studies of urbanisation impacts on moths have focused on comparisons of relatively poorly dispersing taxa, notably groups of micromoths restricted to specific host plants, containing only a few species that can be assessed without invoking light-traps. Many foliage miners, for example, can be sampled by counts of larval mines on different sites rather than evoking any sampling bias from catching adults at light. As representative cases, the assemblage of Lepidoptera frequenting fungus galls on Acacia in South Africa (Rosch et al. 2001) and leaf miners on Quercus in California (Rickman and Connor 2003) have both been used to investigate urban changes to moths. A further concern of urban and near-urban ALAN has been raised from observations that many diurnal Lepidoptera (mostly butterflies) move into urban areas from nearby agricultural or other environments with a propensity for nocturnal moths to be attracted by light to make similar shifts. Such behaviour might lead to urban areas acting as population sinks or ecological traps (Bates et al. 2014). ALANinduced dispersal could be a mechanism whereby moths are attracted from surrounding areas into suboptimal urban habitats in which long-term survival is more unlikely. Records of rarer moths from urban areas may sometimes reflect the incidence of such unfortunate vagrants rather than thriving resident populations and deflect conservation priority. Urban gardens are known to be sinks for some butterflies (Levy and Connor 2004). The extent of this for moths is unknown—but it is possible that some significant periurban moth populations could be rendered vulnerable to such effects. From Boyes et al. (2021a, b), the effects of ALAN can be categorised broadly into four main modes of action across the life cycle (Table 5.4), of which perceiving ALAN as daylight and phototaxis probably has the greatest impacts on moths. Essentially, as the most common focus of attention, moths may be ‘distracted and attracted by artificial light sources’ (Kelnath et al. 2021). Influences on morphological traits could flow from increased mortality at lights over long periods, and Kelnath et al. postulated that conspecific moths in poorly lit and ALAN-impacted

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Fig. 5.6 Subtle impacts of light pollution over time on moths, through sizes of adult Agrotis exclamationis in Germany: mean diameter of right and left eyes in relation to standard body size (Eye diameter/SBL) with different levels of light pollution (low, medium, high) for males (shaded plots) and females (open plots) (sample sizes given as numbers of individuals measured) (Kelnath et al. 2021)

areas may tend to differ in body size, relative eye size and forewing length, thus decreasing with greater light pollution. Their measurements of Heart and Dart moth, Agrotis exclamationis (Noctuidae), specimens collected over 137 years in Germany were not conclusive but implied a trend towards smaller-eyed females in well-lit areas (Fig. 5.6) and some reduction in the male size range. However, ALAN was indeed considered a driver of rapid declines amongst macromoths in the Netherlands (van Langevelde et al. 2017, 2018). Addressing the above two themes, population trends were assessed for 481 moth species from data available over 1985–2015, comparing species that differed in phototaxis and adult activity period. Moths with positive phototaxis or active nocturnally had stronger negative population trends than species that are not phototactic or are diurnal. That difference (Fig. 5.7) implied that ALAN was indeed a factor in the declines of susceptible taxa in areas with high nocturnal sky brightness. Different lamps can have markedly different impacts on moths. In general, shorter wavelengths (such as ultraviolet) are the most effective attractants and are the basis of many commercial moth traps. Taxonomic differences in attractability have also been implied. Noctuidae were more strongly attracted than some Geometridae, for example. Comparisons of the catches from a ‘longer wave’ and ‘shorter wave’ light in southern England showed many more species and individuals of Noctuidae at the latter, whilst Geometridae were not affected (Somers-Yeates et al. 2013, Fig. 5.8). More broadly, LED and sodium lamps are sometimes less attractive to moths than mercury vapour, metal halide or compact fluorescent lamps, supporting recommendations that urban and other ALAN could be based effectively on lamp types that have lower impacts. Many modifications of light sources have been suggested, but an overall reduction in lighting—much of which is regarded as non-essential—is the most important step to restrict losses of moths and other nocturnal insects. Calls for wide adoption of ‘dark infrastructure’ to conserve biodiversity and ecological

5.6

Light Pollution

Fig. 5.7 Mean population trends of moth species in the Netherlands that differ in (a) phototaxis and (b) adult circadian activity. Sample sizes (species number) of each group are (a) 384 (attracted), 54 (occasionally attracted), 20 (not attracted) and (b) 23 (diurnal), 370 (nocturnal), 82 (both); 82% of 384 species attracted to light and 85% of 54 species occasionally attracted to light are nocturnally active; 84% of the 54 species not attracted to light are diurnal (van Langevelde et al. 2018)

Fig. 5.8 Impacts of light wavelength on moth activity in southern England: numbers of moths/night caught at long wavelength and short wavelength lights; Noctuidae (left columns, n = 570), Geometridae (centre columns, n = 81) and others (right columns, n = 68) (Somers-Yeates et al. 2013)

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integrity threatened by ALAN are increasing (Sordello et al. 2022). Evidence is also accumulating that changing the density and spectral emission range of street lights affects urban garden moth communities. In Birmingham, United Kingdom, changing from the narrow spectrum (low-pressure sodium lamps) to broad spectrum (highpressure sodium lamps) increased the diversity of moths in local suburban gardens (Plummer et al. 2016) through changed attractivity. The importance of disruptions by ALAN has become evident from disruptions of migrations of Bogong moths to their aestivation sites in south-east Australia (p. 171), with recommendations that urban centres along the main migration routes should minimise nocturnal lighting during the flight periods. The moths frequently enter buildings during this flight, and attraction to lights at sports grounds and other outdoor venues can cause concerns. A classic example is concern over the large numbers of Bogong moths entering Parliament House, Canberra, generating an investigative report on how to prevent this (McCormick 2005); the main focus of the report’s recommendations was to close windows and switch off lights!

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Chapter 6

Australia’s Moths and Their Habitats

6.1

Introduction

Australia’s diverse moth fauna has long been recognised for its complexity, richness and regional distinctiveness, features fostered by long evolution across a range of different environments in this isolated island continent. It is rich in ancient taxa, including Micropterigidae and Agathiphagidae as the most basal members of the order (Austin et al. 2004), and the vast numbers of other ‘Microlepidoptera’ include many with cryptic feeding habits or that are specialised to consume unconventional materials such as dry/dead foliage. Estimates of moth diversity in Australia remain somewhat imprecise—but there are indeed many species, and the level of endemism is very high, so the fauna has global significance and conservation value. Some endemic lineages have not yet been signalled of conservation concern, but range considerably in diversity. At one extreme, the endemic family Carthaeidae comprises a single species (the Dryandra moth, Carthaea saturnioides) from a limited area of Western Australia—as one of the largest such significant and taxonomically distinctive endemic moths in the region, with wingspan of 80–100 mm. The regionally endemic Anthelidae (Australian lappet moths) are more diverse with nearly 100 described species and occur only in Australia and New Guinea, with different sections of the family found in grasslands or wooded areas and perhaps susceptible to habitat losses. They are a prime candidate group for fuller conservation assessment. In contrast to the well-known moth fauna of the United Kingdom, from which much interest in conservation has flowed and where very few species are endemic, levels of endemism amongst Australian moths may exceed 90% in some families. Numerous endemic complexes of taxa that are difficult to distinguish (p. 11) echo the sentiment of Patrick et al. (2010) for an endemic New Zealand geometrid group (the Notoreas perornata complex) of being ‘a spectacular example of rapid radiation and geographical polymorphism’ and representing a flagship group for conservation of a vulnerable or restricted habitat. A similar comment applies easily to many Australian © The Author(s), under exclusive license to Springer Nature Switzerland AG 2023 T. R. New, The Other Lepidoptera: Moth Conservation in Australia, https://doi.org/10.1007/978-3-031-32103-0_6

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moths and extends to cover the moth fauna of some key habitats and vegetation systems. However, awareness of endemicity and patterns of evolution amongst many moths are refined continually as more information is accumulated. Two primitive small families, Lophocoronidae and Agathiphagidae, exemplify this. Lophocoronidae (with six described species) has for long been regarded as an Australian endemic family, and extant Agathiphagidae, with two species, are known only from Australia and the Solomons, Vanuatu and Fiji. However, fossils from Myanmar have recently been attributed to both these families (Mey et al. 2021) and imply that their origins may be more complex than simply having evolved within Australia.

6.2

Accumulating Information

The discovery and documentation of Australia’s moths have a venerable history. Several moth species were amongst the first series of insects named from the country (Fabricius 1775), and descriptions continue to the present. Many species are also distributed narrowly and restricted largely to particular vegetation types or geographical areas, and many apparently rare species have resisted rediscovery since they were first found. The tiny Lophocorona melanora (Lophocoronidae, above) was described from a single male captured in the Black Mountain Reserve, Australian Capital Territory in 1949 (Common 1973). It has been sought many times since then, but no further individuals are known (as of early 2022), and nothing is known of its biology beyond the specimen being captured flying in the afternoon in May. Black Mountain is by far the most intensively surveyed area of the Territory, and this moth, if it still exists, is assuredly highly elusive. For many restricted Australian vegetation types, inventories of dependent moths are not available, but particular species are known (or strongly inferred) to be both characteristic and restricted to them—and hence potentially vulnerable as those systems change. The insect fauna of ancient Southern beech (Nothofagus spp.) forests in Australia, for example, is considered depauperate in relation to that of New Zealand (McQuillan 1993), but contains a number of endemic Geometridae and local endemics of several families of small moths. More widely, plant families with a long fossil history may host distinctive endemic moths: Austin et al. (2004) noted that Proteaceae supported about 40 moth genera across a variety of families. Native grasses (Poaceae) are hosts of at least 11 families of Lepidoptera—and include radiations such as Hednota, the largest genus of Crambidae, with more than 60 species. The website ‘Australian Moths Online’ operated through the Australian National Insect Collection, Canberra, is a working summary of the fauna, an initial illustrated guide to the recognition of many taxa and an invaluable indicator of the variety of species in each family. Earlier, recognitions were immensely facilitated by the major illustrated text by Common (1990), several regional handbooks displaying selections of characteristic species and the progressive series ‘Moths of Victoria’ (initiated by

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Marriott 2008, and published through the Entomological Society of Victoria, with each of the series accompanied by a compact disc with considerable background information and records of the species treated; nine parts have been published as at mid-2022) is for the first time allowing species-level identifications of much of this important southern mainland fauna and indicating the relative scarcity of the taxa represented. A series of four poster sheets of moths from around Adelaide (South Australia) (BCSA n.d.) facilitates recognition of some of the more conspicuous species likely to be encountered there and some recognitions of early stages aided by McQuillan et al. (2019). Most recently, a synopsis of moths of the Australian Capital Territory (Cocking et al. 2022) illustrates about 700 species from this relatively small area as an indication of the high regional diversity present. Collectively, the patterns of documentation are shown through an annotated bibliography of books focussing on Australian moths (Kitching and Edwards 2020). Many of those works are cited in the context in this book. Many also remain indispensable to understanding the national moth fauna. The very recent (MABA 2022) foundation of the organisation ‘Moths and Butterflies Australasia Inc.’ may provide a forum for future advances in conservation focus and activity, as well as for basic documentation and spread of information, as the first attempt to establish a working national network of Lepidoptera enthusiasts in Australasia. Richness is indicated also through a published Checklist of Australian Lepidoptera (Nielsen et al. 1996). The above website (in October 2021) estimated the moth fauna as about 22,000 species, of which about half are undescribed. This figure is indicative of the high variety of moths present—but also of the great uncertainties over the ‘real’ diversity present in Australia and the precise identities of many of the specimens encountered. It also suggests that most species-level conservation and ecological studies are, by default of better knowledge, restricted to relatively few ‘better-known’ moth groups, namely ‘macromoth’ families in which taxonomic uncertainty is least, public and hobbyist interest is greatest or can be encouraged and for which some biological framework is most likely to exist.

6.3

Features of Australia’s Moth Fauna

The great variety of Australia’s environments are each reflected in local elaborations and radiations within this diverse array, together with the unique (and also highly endemic) flora on which many moth species depend and with which they have coevolved. Many of the most unusual ecological associations of Australia’s moths reflect this plant variety, but a number of more unusual and ecologically intricate feeding associations are also found, some associated with coprophagy. Two examples are noted here. First, larvae of a number of ‘Scat moths’ feed and pupate within the faecal pellets of marsupials, with those faeces composed largely of eucalyptus leaves on which the mammals feed. Those of Telanepsia occur within pellets of the Koala (Phascolarctos cinereus) and possums (Common and Horak 1994), with related moths associated with the faeces of wallabies. Many related moth species

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remain to be characterised fully, and it is possible that increasing scarcity of koalas over much of their range might be detrimental to the moths. Second, larvae of the Antbed parrot moth (Trisyntopa scatophaga) and its allies feed within termite mounds where they are associated with nesting parrots that are themselves of serious conservation concern because of illegal captures for the aviculture industry (p. 165). Larvae eat the excreta of the parrot nestlings, and their natural history is outlined by Zborowski and Edwards (2007) and Cooney et al. (2009). The life history of Trisyntopa neossophila is timed so that larvae hatch around the same time as parrot eggs. Different moth species are associated with different parrots, all of them rare, threatened and highly localised. Both these cases have aroused interest from these unusual associations. Both are members of the largest family of moths in Australia, Oecophoridae (mallee moths). These have diversified massively in association with Eucalyptus and related Myrtaceae, a major component of Australia’s flora, and larvae of many species feed predominantly on dead foliage on the ground. More than 5000 Australian species have been recognised (Common 1994) and local richness can be high, although the distribution of species is very incompletely known. Many species are known only from a few specimens captured at light or reared from confined samples of forest leaf litter, but Oecophoridae are important in the breakdown and recycling of normally persistent eucalypt foliage, as a major group of insect decomposers. They occupy important roles in the ecology of Australian forests. Although worldwide in distribution, Oecophoridae reach their greatest richness in Australia, and it is also the second largest family of moths (after Geometridae) in New Zealand, with 247 species across 28 genera (Hoare 2005) to still represent ‘an impressive endemic radiation’. Hoare acknowledged the high conservation value of Oecophoridae in New Zealand, for three reasons: (1) that it includes a number of enigmatic or ‘lost’ species that have not been recognised for many years; (2) the level of endemism at both species and genus levels is nearly 100% for native taxa; and (3) the detritivorous larvae are probably ‘key players’ in recycling materials in forests and other ecosystems. These aspects are equally valid in Australia, where their massive diversity, focused by Common (1994, 1997 2000) into six major genus groups, renders them likely to be a significant functional group with many locally distinct endemic assemblages. Oecophoridae are significant also in temperate South America, where studies on the fauna of central Chile continue to reveal new locally endemic genera and species in forest and urban enclave environments (Urra 2013, 2022). Urra (2022) considered that many additional species await discovery, with recent attention substantially increasing the known richness of the family. As in New Zealand (Hoare 2005), Australian Oecophoridae might prove to be valid indicators of environmental changes, with litter-feeding larvae perhaps vulnerable to desiccation as forest fragments are exposed through increasing edge effects, as well as their susceptibility to fires. In common with many other insect groups in Australia, impacts of such events on oecophorids can only be implied—but, for any such low-mobility litter-frequenting group with numerous localised species, may be supposed severe.

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Taxonomic knowledge and ability for non-specialists to recognise species are generally most advanced for some macromoths, but several recent revisions and overviews help to redress this imbalance. Likewise, the richness of different families ranges from single members to many hundreds of included species. Almost every taxonomic investigation on the fauna in recent decades has led to descriptions of additional species, collectively across a wide range of families. Especially for some groups of microlepidoptera, reliable recognition of species and estimates of richness are still very tentative. Uncertainties are exemplified by the following quotations on the richness of selected families from Zborowski and Edwards (2017): Nepticulidae (‘. . . no doubt several hundred species will be found’), Opostegidae (‘ . . . there are probably hundreds’), Heliozelidae (‘. . . many undiscovered ones exist’), Adelidae (‘. . . they have not been studied in Australia’), Tineidae (‘. . . several hundred more known to be present’), Elachistidae (‘. . . many still to be discovered’) and Gelechiidae (‘. . . about 800 recorded species in Australia but at least as many are unrecorded’). Despite continuing investigations, many such families cannot yet be used meaningfully in assessments of richness or conservation need in Australia— other than as evidence of very considerable diversity, and supposed habitat and geographical restrictions with likely increased but hidden vulnerabilities as their circumstances change. Moir and Young (2022) have drawn attention to the rapidly changing awareness of two micromoth families in south-west Western Australia. Dedicated fieldwork (over 2011–2020) led to the discovery of an estimated 215 undescribed species of Heliozelidae, with accompanying suggestion that numerous other species have not yet been detected. Micropterigidae were discovered in Western Australia in 2012, and the three known species represent two undescribed genera. All have very small known distributions, susceptible to fire or other stochastic events that could envelop their entire range. A progressive biological framework (Common 1990; Zborowski and Edwards (2007, 2017) enables many broad generalisations on habitat relationships and distributions of various moth taxa to be made, but studies on individual species and assemblages remain sparse. As noted above, many patterns of incidence, richness and species’ requirements are still to be clarified. Nevertheless, it is clear that many taxa are indeed both geographically and ecologically restricted and that many species have not been rediscovered since they were described up to a century or more ago—so their current existence is uncertain. The relatively precise distribution mapping and biological knowledge of many moths in Britain, and to a lesser extent elsewhere in the northern temperate region, and the capability to investigate anomalies as they are discovered, is an invaluable guide to conservation need. This can then be focused on a small number of inhabited sites in which conditions can be appraised and managed to benefit the insect. That some species are known from only one or few sites is a realistic perspective of needs—but careful investigation may still be needed to determine whether conditions are indeed optimal. One important consequence of a long history of collecting Lepidoptera is that ‘rare’ (i.e. ‘desirable’) species may be documented more fully than many common species that are not sought actively by collectors and as a legacy apparent in many institutional depositories for historical moth collections. As Young

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Fig. 6.1 Distribution of the Belted beauty moth, Lycia zonaria britannica, in England and North Wales: post-1980 records as black circles; pre-1980 records as open circles (Howe et al. 2004)

(1997) noted for Britain, following the Victorian era of widespread collecting it became possible to list reliably the locations where many of the scarcer and more interesting moths occurred, as a foundation for more recent assessments of change. That basis is very sporadic in Australia, but the major institutional collections are indeed founded on the accumulations of hobbyists: for the far more popular butterflies, Moulds (1999) estimated that some 80% of specimens in the country’s major museum collections were collected by non-professionals. Again, more commonly for butterflies, it is sometimes unclear whether the species is thriving at a given site or simply ‘hanging on’ as conditions deteriorate. Many Australian moths are indeed known from single or few sites—but background knowledge on distribution and biology is generally far less convincing to evaluate conservation status and need, because much apparently suitable habitat has not been explored and doubts remain over whether the insect is distributed more widely. In short, the case for recommending conservation priority or action from sound evidence of need is often less convincing. For Britain, in addition to the New Forest burnet (Zygaena viciae, p. 109), a number of other moths of conservation concern have not been found to be more widespread despite prolonged and extensive targeted surveys. Well-documented examples include (1) the Rosy Marsh moth, Coenophila subrosea (Noctuidae), known from five raised mire sites in central Wales following its discovery on one site in 1965 after being presumed extinct in Britain for over a century (Fowles et al. 2004); (2) the Belted Beauty moth, Lycia zonaria britannica (Geometridae), an endemic subspecies now known from three sites in north-west England and north Wales, with the disappearance from other regional sites confirmed (Fig. 6.1) (Howe et al. 2004); and (3) the Barberry Carpet moth, Pareulype berberata (Geometridae), formerly widespread but with losses of the larval food plant (Common barberry, Berberis vulgaris) leading to the survival of only one known population by the 1980s (Waring 2004). Conservation efforts for such species (1) have a very clear and circumscribed initial focus and area and (2) can readily be justified by the sound allocation of some category of threat and formal recognition of this. Both these provisions are rarely confident for Australian moths.

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Fig. 6.2 Distribution of Proditrix nielseni in Tasmania: moth records (black spots) superimposed on the distribution of the larval food plant (Richea pandanifolia) (small spots, each representing presence in a larger survey square) (based on McQuillan 2003)

As discussed later, much conservation concern arises directly from the perception of real or presumed restricted distributions, with implications of possible narrow-range endemism and consequent vulnerability. For almost all such species, knowledge of fundamental ecology and other factors and threats to populations is poor. Even for most moths of peculiar taxonomic or ecological interest in Australia, such precise delineations of distribution and loss are impossible or very difficult to approach—although specialised habitat features (such as host plants with restricted ranges) may indeed define the maximum possible extent of restricted and circumscribed specific conditions. The anomalous Tasmanian ‘Pandani moth’, Proditrix nielseni (allocated by McQuillan 2003, to Plutellidae s.l., later placed in Glyphipterygidae), was described from three adults from separate localities (Fig. 6.2). Larvae feed in the crowns of ‘pandani’, Richea pandanifolia (Epacridaceae), which is much more widely distributed. The genus occurs also in New Zealand, but P. nielseni is the only species known from a dicotyledonous host. The wider distribution of Richea in southern Tasmania leaves the possibility for the moth to occur elsewhere across this remote area. However, McQuillan (2003) noted that the ‘very discontinuous distribution’ then evident for the moth linked with many stands of Richea not supporting it. P. nielseni was regarded as a ‘weak and reluctant flier’ and uncertainty over its distribution is accompanied by an apparent lack of attraction to light. Detection, as for many other moth species, is largely fortuitous. Some key ecological groups, such as the ‘aquatic moths’ (Pyralidae) with larvae feeding on or in freshwater vegetation, have only recently been assessed to augment historical data (Hawking 2014). Hawking recognised 54 species of Australian aquatic Acentropinae, across 17 genera, and found 7 genera and 10 species were undescribed. However, preliminary assessment suggested that none was critically

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endangered or endangered, whilst two species were considered vulnerable and—as in many other moth groups—a far higher proportion (23 species) could not be appraised reliably from the limited information available. Attention to these moths had otherwise been very limited—several species were surveyed and examined from the 1980s onwards as part of a wide range of herbivores as possible classical biological control agents for hydrilla (Hydrilla verticillata), one of the most damaging aquatic weeds invading the United States, but none was selected for introduction (Purcell et al. 2019). Other assemblages, such as rainforest moths in northern Queensland, have been revealed as far more diverse and less taxonomically documented than earlier supposed. In short, despite the masses of material in major institutional collections and some private collections, much basic descriptive and biological work remains, to fully characterise Australia’s moth fauna and amplification of that knowledge to wider conservation contexts—such as using moths as bioindicators or in ‘predictor sets’ (Kitching and Ashton 2013) or other surrogates for wider insect diversity in key habitats—is still fragmentary. Surveys, predominantly using light-traps, continue to reveal high and varied moth diversity in many parts of Australia. However, most such surveys are relatively recent and, other than for occasional or fortuitous earlier records from the same localities (such as ‘traditional collecting sites’, mainly close to settlements), provide little evidence for historical declines or changes in assemblages. Most concerns for losses are based on recent evidence of vegetation loss and land change. The size of Australia and the complexity of its vegetation types and climatic regimes is reflected in the recognition of a series of 89 ‘bioregions’, whose variety is linked also with the proliferation of plant-associated insects at scales from regional to far more local—but mostly comprised almost entirely of endemic taxa. Moths are a significant constituent amongst the herbivore groups, with the distributions of many determined by that of their host plant(s) or broader vegetation structure or climatic requirement and in some cases also reflecting biogeographical history. As examples, the alpine/subalpine grasslands of Tasmania and the south-east mainland support characteristic assemblages of Geometridae not found at lower elevations, lowland native grasslands harbour endemic sun-moths (Castniidae) and the rich and complex moth fauna of Queensland’s tropical rainforests have many associations with the fauna of New Guinea and mostly do not extend towards the south of Australia. At a global scale, these distributions, and others—some reflecting distinct taxonomic lineage affiliations—support older Gondwanan elements restricted largely to the south and more recent northern elements linked to the fauna of the Oriental region and intervening island groups. However, whilst this idealistic dichotomy is a very attractive ‘explanation’ of moth ranges in Australia, the known distributions of many moth taxa transcend such a simplistic spatial separation. Patterns of faunal mingling, especially along the east coast, with the low coastal areas and elevated Great Dividing Range providing cooler high elevation areas, are complex, so that some typically southern insect groups extend far northward and the converse. Likewise, the Nullarbor Plain is an effective barrier that has enabled the recent independent evolution of insects in the south-west

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and south-east parts of temperate Australia, to produce distinctive biota in each. Castniid moths, for example, occur in both regions but without any overlap of species—and face parallel patterns of habitat loss in the two regions. Some higher taxa of moths are Australia-wide, but many of their constituent genera and species are far more limited as more local regional endemics. As likely for all groups of insect herbivores, the diversity, distribution and endemism patterns of native flora both influence and determine the distributions of moths in Australia. Endemism is a key driver of conservation priority, with the presumption that narrow-range endemic species are by definition restricted and potentially threatened. Detection and definition of areas of plant endemism may thereby help to guide conservation priorities by focussing on equally restricted moths. However, as Crisp et al. (2001) discussed for Australian flora, recognising centres of endemism is scale-dependent, ranging from the continental endemism of much of Australia’s flora through which major areas (such as the north-east forests, the south-west botanic province and others) are more local centres, each including progressively more restricted areas defined by flora (and insect herbivores) not known elsewhere and comprising a suite of distinct phytogeographic regions. Analysis of plant distribution records (representing about half the approximately 1700 vascular species then recorded in Australia) and assessing several indices of endemicity enabled the detection of 12 major centres of plant endemism and a range of smaller centres (such as the Australian Alps and the Grampians area of Victoria). All the major centres are near coastal. Plant endemism and plant species richness are separate parameters, not necessarily co-incident but both important in fostering local and characteristic moth assemblages. Any partitioning scheme, such as that of Crisp et al. (2001), is a valuable indicative guide to areas/environments in which endemic moths might occur and where surveys may merit priority. Smaller areas of plant endemism are potentially rewarding targets for consolidating knowledge of endemic moth needs and distributions. Reflecting gaps in the fine-scale mapping of many Australian plants, equivalent scale distributions of most moths are also unknown. The principle that assemblages containing many narrowly distributed species gain higher conservation priority than those containing mostly wide-ranging species is well-established in considerations of protected areas. One basis for endorsing this is a survey of restricted habitats: in Australia, most ‘flagship moths’ (Chap. 8) are associated with such environments, but knowledge of the (perhaps equally significant) species accompanying them there is inadequate, so the extent to which they represent endemic assemblages is unknown. Perhaps particularly in the tropics, species’ ranges can be smaller than in northern temperate zones, but Beck et al. (2018) emphasised the difficulties that flow from undersampling, the incomplete observations of the species that occur at a site. Outcomes include the following: (1) small-ranged species are typically also locally rare and (2) more likely to be overlooked in local inventories than locally abundant species for which the ability to detect them confers a wider documented range. The relatively well-documented Sphingidae of parts of East Africa furnished sufficient records to suggest range sizes, from which Beck et al. showed that ‘missed species’ (those not found in the field but

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expected from range maps) occupied smaller ranges than species common enough to be found. Many moths have been recorded only from very restricted biotopes and/or are so far associated only with host plants or other resources that are themselves very restricted. Many of these specialised associations are known or suspected to occur, with the strong implication that the fate of the moth is then linked strongly with that of (most commonly) its larval host plant. Large numbers of monophagous or oligophagous moth species are thus potentially vulnerable to local or more extensive vegetation clearance and other changes. Most widespread polyphagous generalist moths are far less susceptible, but the level of ecological flexibility for most of these, other than a few pest species, is largely unknown. As noted earlier, the larval food plants of most Australian moths have not been documented fully—the extents of these gaps are illustrated by a summary of the geometrid subfamily Larentiinae, a largely endemic representation of more than 45 genera and about 270 described species (Schmidt 2016). A comprehensive literature review augmented by Schmidt’s personal records yielded larval host plant records for only 51 species, and for many species, these were isolated or opportunistic records rather than the outcome of full investigation. Schmidt’s comment that ‘the life histories of the Australian larentiine moths have barely been studied’ extends easily to numerous other taxa. Many are also more locally endemic—a quarter of the 105 larentiine species found in Tasmania, for example, are endemic to the island state (McQuillan 2004) many of them are very restricted there. Only 16 species of Larentiinae were included in an earlier listing of accumulated records of the larval food plants of 280 Australian moths—of which around half were Geometridae (McFarland 1979, 1988). In short, the biological template for assessing even the most basic resource needs of most Australian moths is woefully inadequate, and original fieldwork and study are needed for almost any species suggested to have conservation significance. Indeed, the most complete studies on moth population dynamics and movements have been undertaken on species or complexes of endemic and cosmopolitan pasture pests, principally Noctuidae. Major infestations are usually heralded by flights of adult moths—hence the relevance of studying migration paths and distances as an aid to predicting pest incidence—and influenced strongly by weather. Pest outbreaks of the endemic species are associated with vegetation growth in early autumn, after drought-breaking inland rains. Major infestations of the cosmopolitan species tend to occur in tropical/subtropical crops and improved pastures, whilst most of these are less important agricultural pests than their endemic counterparts further south (Farrow and MacDonald 1987). The main species involved (Table 6.1) include several ‘sibling pairs’ of endemic/widespread species with overlapping distributions. Amongst these major taxa, Persectania is an Australian endemic genus. A number of more minor migratory noctuids are also important pests of crops, but rarely attain outbreaks. Although it is assumed widely that many moths disperse only locally, the longdistance flights exemplified by the Bogong moth (p. 171) may be more common in other species than generally supposed. An extended period of light trapping

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Table 6.1 Major noctuid pests of Australian agriculture: endemic and cosmopolitan taxa (Farrow and McDonald 1987, nomenclature updated) Endemic species ‘Sibling pairs’ Helicoverpa punctigera (Native budworm) Agrotis infusa (Black cutworm, Bogong moth) Mythimna convecta (Common armyworm) Others Agrotis munda (Brown cutworm) Heliothis punctifera (Lesser budworm) Persectania dyscrita (Inland armyworm) Persectania ewingii (Southern armyworm)

Cosmopolitan species Helicoverpa armigera (Cotton bollworm) Agrotis ipsilon (Greasy cutworm) Mythimna separata (Northern armyworm) Mythimna loreyi (Sugarcane armyworm) Spodoptera exempta (Day-feeding armyworm) Spodoptera exigua (Lesser armyworm, Beet armyworm) Spodoptera litura (Cluster caterpillar, Tobacco cutworm) Spodoptera mauritia (Lawn armyworm) Chrysodeixis argentifera (Tobacco looper) Chrysodeixis eriosoma (Green garden looper)

designed to capture only migrating moths on two elevated sites in New South Wales used traps deployed on elevated towers (40 and 50 m high) at the two sites and directed upwards to minimise attraction of ground-level moths (Gregg et al. 1993). One site (Point Lookout: PL) had no other lights within 5 km, and the other (Mount Dowe: MD) had only intermittent lighting from a building at the tower base. Very high proportions of the more than 60,000 moths captured over almost 5 years were Noctuoidea and Sphingidae, with ‘other moths’ mainly comprising pyralids. Known or suspected migrant species of Noctuoidea (by far the predominant family with 44 [PL] and 6 [MD] species, with the smaller catch of Sphingidae dominated by Hippotion scrofa) were also predominant, with 94.6% [PL] and 99.9% [MD] of individuals at the two sites. However, the catches also included at least 24 species not previously suspected to be migrants and exemplify the wider uncertainties over the dispersal prowess of numerous Australian moth species. Not all such crop pests are strong migrants, but most show biological idiosyncrasies of wider relevance. The brightly coloured diurnal Vine moth (Phalaenoides glycine, Noctuidae) usually flies only short distances, but is unusual in being a native moth that has apparently largely abandoned its native host plants (with early records including native species of Asteraceae, Dilleniaceae and Fabaceae) to become a significant pest of grape vines (Cordingley 1980). By the early twentieth century, it had become widespread across grape-producing areas in the south, undergoing two

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to three generations a year and the larvae feeding on foliage and young grape bunches. Most attacks are restricted within a vineyard rather than extending across the whole crop.

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Kitching RL, Ashton LA (2013) Predictor sets and biodiversity assessment; the evolution and application of an idea. Pac Conserv Biol 19:418–426 Kitching RL, Edwards ED (2020) Books about Australian moths 1805-2020: an annotated bibliography. Aust Entomol 47:119–154 MABA (Moths and Butterflies Australasia Inc.) (2022) Newsletter no 1. Canberra. www.maba. org.au Marriott PB (2008) Moths of Victoria (Part 1) Silk moths and allies – Bombycoidea. Entomological Society of Victoria, Melbourne McFarland N (1979) Annotated list of larval foodplant records for 280 species of Australian moths. J Lepidopt Soc 33(Suppl):1–72 McFarland N (1988) Portraits of South Australian geometrid moths. Allen Press, Lawrence, KS Mey W, Leger T, Van Lien V (2021) New taxa of extant and fossil primitive moths in South-East Asia and their biogeographic significance (Lepidoptera, Micropterigidae, Agathiphagidae, Lophocoronidae). Nota Lepid 44:29–56 McQuilllan PB (1993) Nothofagus (Fagaceae) and its invertebrate fauna – an overview and preliminary synthesis. Biol J Linn Soc 49:317–354. https://doi.org/10.1111/j.1095-8312-1993. tb600910x McQuillan PB (2003) The giant Tasmanian ‘pandani’ moth Proditrix nielseni, sp. nov (Lepidoptera: Yponomeutoidea: Plutellidae s.l.). Invert Syst 17:59–66 McQuillan PB (2004) An overview of the Tasmanian geometrid moth fauna (Lepidoptera: Geometridae) and its conservation status. J Insect Conserv:209–220 McQuillan PB, Keane D, Grund R (2019) Caterpillars, moths and their plants of southern Australia. Butterfly Conservation South Australia, Adelaide Moir ML, Young DA (2022) Insects from the southwest Australia biodiversity hotspot: a barometer of diversity and threat status of nine host-dependent families across three orders. J Insect Conserv. https://doi.org/10.1007/s10841-022-00443-x Moulds MS (1999) The history of Australian butterfly research and collecting. In: Kitching RL, Scheermeyer E, Jones RE, Pierce NE (eds) Biology of Australian butterflies. CSIRO Publishing, Collingwood, pp 1–24 Nielsen ES, Edwards ED, Rangsi TV (eds) (1996) Checklist of the Lepidoptera of Australia. Monogr Aust Lepid no 4. CSIRO Publishing, Melbourne Patrick BH, Hoare RJB, Rhode BE (2010) Taxonomy and conservation of allopatric moth populations: a revisionary study of the Notoreas perornata Walker complex (Lepidoptera: Geometridae: Larentiinae), with special reference to southern New Zealand. N Z J Zool 37: 257–283 Purcell M, Harms N, Grodowitz M, Zhang J, Ding J et al (2019) Exploration for candidate biological control agents of the submerged aquatic weed Hydrilla verticillata, in Asia and Australia, 1996-2013. BioControl 64:233–247 Schmidt O (2016) Larval food plants of Australian Larentiinae (Lepidoptera: Geometridae) – a review of available data. Biodiv Data J 4:e7938 Urra F (2013) Contribucion al conocimiento de los Oecophoridae (Lepidoptera: Gelechioidea) de Chile central. Acta Entomol Chil 33:31–44 Urra F (2022) Dos nuevos generos monotipicos de Oecophoridae (Lepidoptera: Gelechioidea) de Chile central. Revta Chil Entomol 48:595–603. https://doi.org/10.35249/rche.48.3.22.13 Waring P (2004) Successes in conserving the Barberry Carpet moth Pareulype berberata (D. & S.) (Geometridae) in England. J Insect Conserv 8:167–171 Young MR (1997) The natural history of moths. Poyser, London Zborowski P, Edwards T (2007, 2017) A guide to Australian moths. CSIRO Publications, Clayton. South (2017: reprinted with corrections)

Chapter 7

A Closer Focus: Threats to Australia’s Moths

7.1

Introduction

The major anthropogenic degradations to Australia’s environments have occurred over the last two centuries, during which European settlement has vastly changed the state of much of the continent and over which large-scale land transformations have overlain or replaced the far earlier traditional (and largely more sustainable) practices of First Australian Peoples. Early European settlements, predominantly coastal or near coastal, had little effect on the inland, but coastal environments—especially along the east and southern regions—have continued to undergo severe changes as human populations and their needs have increased to the present. These areas are the most clement for settlement and also those of the greatest insect richness and habitat variety. They are also the most fertile, so most food crops are also concentrated in those areas, increasing vastly the areas affected by people.

7.2

Loss of Native Vegetation: A Key to Australian Moth Conservation

Agricultural conversion has become a major component of land-use change, whereby much natural vegetation has been cleared and replaced by large-scale crop monocultures, predominantly of introduced plants that are subsequently the focus of attack by alien pest insects, commonly with the need for imposed suppression measures. Subsidiary impacts thus include pest management measures— focused pesticides to counter undesirable arthropods and plant weeds and ‘safe’ biological control involving alien agents—fertiliser applications and general reduction of previously extensive natural insect habitats to tiny isolated fragments. Assuring adequate water supply to sustain crops remains both practically and politically difficult, with impacts on all inland water environments in the region. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2023 T. R. New, The Other Lepidoptera: Moth Conservation in Australia, https://doi.org/10.1007/978-3-031-32103-0_7

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Table 7.1 Categories of grassland in Tasmania and their representation of Geometridae: Xanthorhoini (total number [n] of moth species, 25) (McQuillan 1999) Highly modified grasslands

Lightly modified grasslands

Unmodified grasslands/ sedgelands

Typically at lower elevations, 26 sites with a cover dominated by introduced grasses and weeds; high stocking rates; recent phosphate fertiliser applications Total n, 4; range 0–4; no species restricted to this category Three groups, successively with 14, 9 and 8 sites at increasing intermediate elevations; most sites based on native Poa spp., but some sites dominated by Themeda triandra Total n, 19; successively 7, 10 and 18; three species restricted to third (highest) sites Typically montane, but at range of elevations; most of the 25 sites based on Poa spp. but some are dominated by sedges; few or no stock, but variable grazing pressures from native herbivores and rabbits, occasionally from hepialid moth larvae Total n, 21; highest mean species number, and six species restricted to this category; two others shared with the highest elevation lightly modified grasslands

In parallel, much of inland Australia is used for pastoral activities—the earlier traditional image of Australia ‘riding on the sheep’s back’ reflecting economic wealth has suffered somewhat in recent years, but both cattle and sheep production and export remain highly significant factors in Australia’s national economy. Much is now based on ‘improved pasture’, characterised by introduced grasses and varieties more nutritious than native grass species and allowing greater carrying capacity for stock and agriculture—whereby the grasslands are ploughed and planted to crops. Much of Australia’s vast grassland area has thus now been changed in composition, to the extent that lowland native grasslands in the south-east have been described as ‘Australia’s most endangered ecosystems’ (Kirkpatrick et al. 1995). Impacts on moths were illustrated by the distributions of the 53 species of Xanthorhoini (Geometridae) on native grasslands in Tasmania, which allowed McQuillan (1999) to project a ‘spectrum of susceptibility to local extinction’ across the relatively small geographical area in relation to changes to the grasslands. Species representation was inspected across 90 grassland sites of varying sizes and conditions. Moths (collectively 25 species) were found on 82 sites, and assemblages differed across five categories of grassland that represented different degrees of degradation and change, a pattern seen more clearly in treating the sites in three categories (Table 7.1). In particular, mirroring trends more widespread on the mainland, lowland grasslands in Tasmania have declined continually, with formerly extensive areas now reduced to small remnants separated by large areas unsuitable for the moths to persist. Species diversity declined as their habitats were modified, in large part reflecting losses of the native herbs on which larvae feed. Few species have successfully moved to feed on introduced herbs, and only three of those Tasmanian moth species can tolerate the most heavily altered grassland such as weedy urban

7.2

Loss of Native Vegetation: A Key to Australian Moth Conservation

139

lawns. Greater richness persists in remnant patches in which native herbs have remained reasonably diverse. However, vulnerability also arises from reliance on unusual food plants and narrow host ranges, restricted distribution and small population size, with continued clearing and pastoral conversion being the major threats to the moths. McQuillan (1999) suggested that conservation of these xanthorhoines largely involves maintaining native interstitial herbs in grasslands, with these affected by grazing intensity, fire regime and climate—but with more information needed on the impacts of each of these. As in many other environments, multiple uses and conflicting conservation priorities can thwart measures to benefit moths. Fire regimes recommended for the conservation of some rare plants, for example, may not coincide with those optimal for focal insects in the same area. As Patrick (2004) commented for New Zealand’s rich tussock grassland moth fauna, conservation ‘will require much debate, strength and action in the face of competing demands’. McQuillan’s contention that xanthorhoine moths are useful indicators of grassland integrity because of their sensitivity to the herbaceous component of those communities also reflects them being diverse, abundant, conspicuous and easy to sample and identify. They may have wider such applications in south-east Australia. Although a lack of fundamental ecological information largely precludes the detailed evaluation of Australia’s grassland moths as indicators equivalent to that possible for parts of Europe (Habel et al. 2019), there is little reason to doubt that assemblage changes due to succession or other imposed stressors will show similar trends—with progressive losses of specialist species that depend on particular grassland components or microclimates, and gains by the colonisation of species better adapted to the new conditions and reflecting the local pool of taxa available. The spread of urban areas has also progressively enveloped native grasslands, with conservation concerns (in particular for sun-moths) leading to vigorous debate and advocacy (p. 162). Most of Australia’s major cities and towns have been developed on previously natural lands rather than on ground earlier cleared for other purposes. Urbanisation, together with agriculture and some forestry expansion, has thereby often subsumed relatively pristine natural environments. Urban areas continue to expand, with periurban areas succumbing to the establishment of new suburbs and their supporting infrastructure, and projections for the further increased land needed to house a growing human population. Forest and savannah regions have also been cleared extensively, with continuing demands for timber leading to ongoing pressures by the timber industry to exploit native forest, including irreplaceable old-growth eucalypts. Many livelihoods and whole communities depend on that industry, so serious social and economic consequences arise over moves to reduce or prevent exploitation or to protect native forests. Australia’s forestry plantation estate comprises two rather different categories. Needs for hardwood timber are augmented by eucalypt plantations (mostly of Tasmanian blue gum, Eucalyptus globulus), so producing even-aged stands and evenly spaced trees replacing the heterogeneity of natural forest, sometimes using species not native to the planting area (so essentially aliens from elsewhere in Australia) and needing pest control to protect timber yield. Demands for softwood

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are met through plantations of alien conifers, notably Monterey or Radiata pine, Pinus radiata, now replacing native vegetation over more than a million hectares, much of it land previously classed as ‘wet sclerophyll forest’ dominated by eucalypts, with a small proportion on previously cleared pastoral land. Both categories are harvested in quite short rotations in the range of 20–30 years. Biological contexts differ; plantations of eucalypts are often near native eucalypt forests, with the potential for native insects to move over to the new resource in the region, whilst the more dramatic host transfer to pines marks a far greater biological step, one that many species cannot accomplish. The impacts of plantation forestry on native insects clearly reflect their differences from parental native vegetation and the extent to which moths or others can overcome these, together with their proximity to source populations. A comparison of the insect fauna of E. globulus plantations and native Eucalyptus marginata-dominated woodland in southern Western Australia showed their compositions to differ considerably (Cunningham et al. 2005). Fewer species occurred in plantations, where a few species were very abundant. Altogether, the 295 macromoth species recorded represented 26 families, with Oecophoridae the most abundant in plantations. Almost two-thirds (104/155) of the species found in plantations also occurred in remnant woodland, and, in general, the moth assemblages of remnant woodland sites were more similar to each other in species composition and abundance than they were to adjacent plantation sites. Despite E. globulus being alien to Western Australia—Strauss (2001) used the term ‘seminative’ to reflect this—it clearly has considerable compatibility for the insects of its numerous congeners as it is spread around Australia. That wider species pool is the source of plantation pests that may cause massive economic damage and include a few moths that undergo sporadic ‘outbreaks’ to reach damaging numbers. Twenty moth species were listed by Strauss (2001) as recorded pests of Australian eucalypt plantations. Few are widespread. The most frequent concerns are from a common defoliator, the Autumn gum moth (Mnesampela privata, Geometridae) (p. 145). In general, plantation forests are considered widely to be far poorer than native forests for ‘biodiversity’ because of being monocultures. Despite the provisions of the Environment Protection and Biodiversity Conservation Act 1999 (EPBC), habitat loss for Australia’s biodiversity continues largely unrecorded and unabated. EPBC came into force in 2000 with part of its remit to assess and approve/disapprove proposed actions based on whether they might have ‘significant impact’ on threatened species, threatened ecological communities or migratory species. Most of those actions involve habitat loss, much with unpredictable impacts, and the outcome of an application may involve approval, prohibition or modification of the action(s) proposed. However, a review by Ward et al. (2019) found the EPBC Act ineffective in protecting habitats of terrestrial threatened species and threatened ecological communities across many higher taxa. Over 2000–2017, more than 7.7 million hectares of potential forest and woodland habitat was cleared in Australia, with 93% of this not referred for assessment so the impacts of losses have not been evaluated. Because other vegetation types were not included in these totals (comparative remotely sensed data were available for only treed systems), the losses from low vegetation and grassland conversions would

7.3

Fire

141

increase this habitat degradation further. Ward et al. (2019) considered that Australia’s biodiversity faces increased extinction risks unless major changes in how EPBC is implemented are forthcoming rapidly. Although specific data are sparse, losses of both native grassland and native forest and woodland are likely to have eroded populations of many native insect herbivores, including moths. Some forest moth species, however, have made the substantial host plant change to feed on P. radiata—some becoming sufficiently abundant to be considered pests and demand control. All are polyphagous species that have added pines to their host array. By 1993, around 70 moth species had been reported on P. radiata in Australia (Britton 1994; Britton and New 2004) and, despite some uncertainties over the precise number because of taxonomic confusions, this total is considerably greater than reported from other countries to which Monterey pine has been introduced. Perhaps most notably, representatives of endemic groups, such as some ennomine Geometridae and Anthelidae (as a largely endemic family, found elsewhere only in New Guinea), have made this transition. The uniform homogeneous environments provided by a managed plantation forest, an ‘improved’ pasture grassland or an agricultural monoculture crop, can each favour a small group of native moth species sufficiently versatile to exploit them, but also essentially exclude numerous others. Each may also be susceptible to colonisation by species (native or alien) that can cause economic damage and become the targets for suppression, sometimes by means that can have more wideranging impacts. Likewise, any trends towards increased diversity, such as by native vegetation may lead to countermeasures. Any of the above transformations initially depends on the removal or reduction of native vegetation, either completely or to leave small remnant fragments of these natural habitats of grassland, savannah or forest in an otherwise predominantly anthropogenic landscape. Reduced connectivity between remaining natural remnant patches increases their individual isolation and the vulnerability of species that depend on them. Whereas much information is to hand on such changes to Australian environments, translating those impacts to conservation need for moths is in its infancy. Austin et al.’s (2004) comment quoted in the preface (namely ‘Australian Lepidoptera are increasingly threatened with local or complete extinction from land use change especially in the south and east, but conservation planning to secure their future is only just beginning’) still holds – but with additional realisation that planning is indeed necessary and must be based on greater awareness and understanding of the threats themselves. The following comments enlarge on topics discussed more broadly in earlier chapters.

7.3

Fire

Australia is renowned for its variety of fire-adapted ecosystems, for which fire regimes imposed for human interests or as a consequence of climate changes can markedly change resilience and suitability to long-adapted endemic invertebrates

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(New 2014). Recurrent forest fires are a ‘natural disturbance’ in Australia’s southern temperate forests, and much native insect fauna is presumed to have developed some form of resilience to these. Threats arise from the far greater intensity and extent of climatically induced ‘megafires’ (p. 97) and extensive control burning. The phrase ‘inappropriate fire regimes’ occurs increasingly in Australian conservation assessments and reflects the considerable use of prescribed burning as an important tool in ecosystem management and superimposed on the ‘natural’ fires that have long shaped the Australian landscape. However, most of those natural fires—other than sporadic wildfires—have historically been regarded as low-intensity ‘mosaic’ burns that have helped to retain vegetational and structural heterogeneity across vegetated areas, regenerate successions and reduce the intensity and consequences of more severe fires by reducing the amounts of combustible fuel available. Much Australian vegetation is adapted to, and even depends on, such fire events. Calls for more extensive fuel reduction burns as a response to recent wildfires have led to pressures to burn far larger areas and inevitably move away from the small-scale mosaic burning that can sustain variety. Such practices are often considered ‘inappropriate’ when undertaken uncritically in areas where sensitive plants or animals reside. Together with megafires and other unplanned or uncontrolled conflagrations, they can constitute severe threats. However, the needs to protect human life and property from wildfires will understandably continue to take precedence over most conservation concerns. Impacts on insects are likely to be severe, especially from hot burns over large areas and that destroy heterogeneity and facilitate invasions by alien species and their associates. Whilst direct losses of trees and understorey vegetation and their foliage feeding and saproxylic fauna are the most popular concerns, consequences may be much wider. Not least, the widespread destruction of leaf litter on the forest floor has far-reaching consequences for the numerous moths (and some other insects) depending on that larval food—most notably the diverse Oecophoridae (p. 165) but also the Tortricidae: Epitymbiini, with at least 100 species. Most are associated with the litter of eucalypts and related trees, but Nothofagus litter can also be an important moth resource. Several other moth families also contribute to the important role of comminuting this otherwise tough and persistent litter and consequently to forest health. Many canopy-feeding moths also use ground litter for pupation. All may be vulnerable to fire. Narrow-range endemic insects may be at severe risk from fire. For the Heliozelidae of south-west Western Australia, for example, Moir and Young (2022) noted that several locally abundant species had 90–100% of their known range burned in the Stirling Range bushfire of 2019–2020 and may now be critically endangered or extinct. One species had a total known range of about 2 km2, all of which were burned. Likewise, an undescribed micropterigid was known from a total of about 150 m2 in the Stirling Range National Park, and all of this montane heathland habitat was burned.

7.4

7.4

Climate Change

143

Climate Change

The impacts of climate changes on Australian moths are likely to embrace the wider trends of changed distribution, tolerances, interactions, and resource suitability and access implied—and in some cases already strongly evident—for elsewhere in the world. Increased frequency and intensity of fires, as above, have the potential to drastically change many sensitive habitats. In rainforest environments, transformations of fire-sensitive vegetation to fire-tolerant vegetation may be accompanied by increased droughts. Likewise, increased flooding and sea-level rise may have widespread impacts, including habitat losses that include some restricted coastal environments. However, much of this future can only be implied, although assessments for Australian butterflies (Beaumont and Hughes 2002) have suggested that several notable taxa may become of direct risk. The isolated highland areas in the Wet Tropics, where insect endemicity is demonstrably high (Yeates et al. 2002), parallel the southerly alpine areas in being essentially ‘cooler islands’ in a warmer enveloping landscape and are also vulnerable to changes as warming occurs. Both these ecosystems were regarded by Hughes (2011) as among those most vulnerable to even modest levels of warming. Vegetation changes are likely to be substantial in both. Progressive intrusions of woody vegetation into alpine herb fields, for example, may eliminate the entire current habitats of some endemic moths, and the very limited elevational range largely removes the option of species seeking long-term refuge by moving upward: for many species, ’upward’ simply does not exist. Noting that all of Australia’s natural ecosystems are potentially affected by climate change, Hughes (2011) also cited coastal fringe habitats, freshwater systems and the south-western Western Australia region as especially vulnerable. Together with coral reefs, this array emphasises the broad concerns that arise for the country’s varied biota. Alpine biota are of notable concern as their restricted habitat areas are warmed (with consequences such as reduced snow cover and loss of frost hollows), vegetation changes and opportunities for moving to equally suitable regimes disappear. The open alpine areas of Tasmania and Victoria support radiations of conspicuous diurnal moths (many of them Geometridae, p. 94) as the most diverse component of Lepidoptera, largely replacing butterflies as the most conspicuous insects present. Indeed, some workers have suggested that the widespread diurnal habit may reflect adaptation to warmer daily conditions. For Tasmanian species, Henry et al. (2022) commented that these have ‘evolved from nocturnal, cold-hardy ancestors’, but they may also be vulnerable to additional warming, and changed interactions from species moving upward from lower elevations as those areas become untenable. Some of those species are locally abundant, but many also have very limited or disjunct distributions. One trend that has already attracted considerable attention is the changes in migratory timing of the Bogong moth (p. 171) to alpine areas and its consequences for resident consumers (Green 2010). Responses are far easier to appraise in abundant or widespread species than in those that are already scarce. Two ecologically important alpine moths in Australia

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are significant herbivores on native Poa grasses and, when abundant, can cause extensive grass death with the potential for the denuded areas to be colonised by other vegetation as climate conditions change. An early study on their biology (Chadwick 1966) confirmed that they are distributed widely in Victoria and New South Wales, but they were still regarded as ‘poorly known’ by Parida et al. (2015). Nevertheless, the abundance of both the Alpine grass grub (Oncopera alpina, Hepialidae) and the Alpine case moth (Lomera caespitosae, Psychidae) can be surveyed realistically by searches for their characteristic larval grass retreats and cases, respectively, in Poa tussocks. The moths have rather different host preferences, but grass damage is greatest in areas where their distributions overlap. Species’ presence and some indication of abundance can thus form a base for modelling distribution and change. Neither species was found lower than 1000 m elevation, and future distributions of moths and Poa hosts were modelled for climate scenarios projected for 2030, 2050 and 2070. Models implied an overall trend of declining suitability for the grasses and for the moths, but with responses for the two moths differing somewhat, with greater losses of habitat suitability for L. caespitosae. However, decreased connectivity through increased isolation of habitat patches for both species in Victoria and New South Wales continued along all scenarios. Some populations of L. caespitosae in Victoria were predicted to be lost by 2050, whilst populations of O. alpina would persist, but the latter become more restricted in New South Wales by 2070. Climate, rather than host plant availability, was the predominant restrictor of distributions, but both moths were more restricted than their hosts (Parida et al. 2015). The two species differ in some biological characteristics that may affect their responses to climate change. L. caespitosae larvae feed only on aerial parts of Poa and hibernate under snow cover twice during their 2-year life cycle; adults emerge and oviposit during the warmest quarter of the year. O. alpina is univoltine, and larvae shelter in soil tunnels so are less likely to be exposed to climate extremes. Loss of low-lying coastal habitats from inundation as sea levels rise, and increased storm activity are likely threats to some narrowly distributed insects. Two geometrid moths listed as ‘Vulnerable’ under the state’s Threatened Species Protection Act 1995 in Tasmania are very localised and confined to saltmarsh/dune habitats in the southeast; Dasybela achroa is endemic, and Amelora acontistica occurs also on Kangaroo Island, South Australia (McQuillan 2004).

7.5

Pest Management

As elsewhere, concerns arise from the deployment of pesticides and classical biological control agents against pest insects and others, with perennial concerns over possible non-target effects on native species, and how situations may change in the future. Thus, the Gypsy moth (Lymantria dispar, p. 107) is potentially one of the most serious invasive insect herbivores in Australia and, although it has not yet (March 2022) arrived, extensive planning to thwart its establishment has been in place in Australia

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Pest Management

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since 2009 (Plant Health Australia 2009). Trapping and monitoring for adult Gypsy moths are undertaken commonly by the pheromone lure ‘Disparlure’, which is known from trials to also attract some native species of Lymantria, which must be examined carefully to differentiate them from true Gypsy moth (Horak et al. 2020) and could suffer non-target impacts. Concerns over the impacts of Gypsy moth control are widespread elsewhere (p. 107). European gypsy moth (L. d. dispar), long supposed not to be able to defoliate plantation Pinus radiata, was demonstrated to do so in Spain (Castedo-Dorado et al. 2016), leading to heightened concerns on possible impacts in Australia and New Zealand. The native Autumn gum moth (Mnesampela privata, p. 140) appears to undergo outbreaks only in Eucalyptus plantations and not in native forests (Steinbauer et al. 2001), leading to the suggestion that one approach to prevention might be to move from monoculture Eucalyptus plantations to more mixed-species plantings, as more effective ‘functional mimics’ of native forests. Such a move increases vegetational variety and heterogeneity and greater diversity of generalist natural enemies. M. privata larvae can feed on at least 35 species of Myrtaceae (Steinbauer et al. 2001), but plantation conditions foster localised outbreaks by assuring host plant abundance and uniformity, combining with the moth’s high fecundity to create outbreaks in individual plantations. In contrast to the more extensive ‘eruptive outbreaks’ shown by some northern hemisphere Geometridae in forests, this more resembles a more gradual ‘gradient development’. Elsewhere in the world, some native moths can also become pests of introduced eucalypts (p. 104). As Strauss (2001) commented, calls for mixed-species/subspecies plantings in Australian eucalypt plantations have occurred since the 1970s, and are implied to contain pest attacks. A major perceived benefit is to enhance the availability of natural enemies. Thus, Steinbauer et al. (2001) noted the possible values of flowering plants in inter-rows between trees in providing food for parasitoids of M. privata and that this measure might even entail establishing novel plant communities for specific geographical and tree species combinations. Various such modifications to the management of plantations and adjacent areas—maintaining local natural habitat remnants, enhancing connectivity and improving hospitality of the intervening matrix and within-plantation spaces—may all help to counter pests. In conifer plantations in Wales, open spaces left after felling were associated with increased moth biomass (Shewring et al. 2022), and any such measures to increase environmental heterogeneity in plantations may have value in both conservation and pest suppression. Some of the iconic ‘Giant wood moths’ (Cossidae) in Australia pose a rather different pest problem in eucalypt plantations. Endoxyla cinereus is among the world’s heaviest moths (the large females have been reported as around 30 g, much of which represents the 20,000 or so eggs they may produce during a short non-feeding adult life: Monteith 2011), and is an economically damaging pest of plantations—indeed, Thurman (2022) commented that the Eucalyptus species common in plantations in eastern Australia ‘have been shaped by the Giant wood moth, which is considered one of the most significant pests of the plantations’. It is likely that several cryptic species currently masquerade under this species’ name, because

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‘E. cinereus’ is widespread across southern and eastern Australia, and has been reported from a range of different eucalypt hosts. First instar larvae are dispersed by ‘ballooning’ on silken threads and may be carried considerable distances—but also suffer high mortality rates. The early larval life is poorly known, but wood-boring does not start until the larvae are about 25 mm long. During these later instars, the larvae burrow into the trunk or branches of young eucalypts and in time form upward vertical chambers up to about 25 cm long, in which pupation occurs. The larvae reach up to about 15 cm in length and have long been sought for food by, and play important cultural roles in the traditional life of, First Australians. The presence of larval tunnels is shown by the entrance point being covered by a ‘cap’ of silk and chewed wood fragments, and in due course, a second ‘exit hole’ is formed above this by large larvae, in order for the emerging adult to leave. The life history is suspected to take 3 years or more. Infestation levels in eucalypt plantations can become high, with summaries of earlier accounts (Thurman 2022) including measures of tree numbers attacked in New South Wales of 70.3% (Eucalyptus grandis) and 83.4% (E. grandis x E. urophylla). Consequences include severe weakening of trees, rendering them easily broken during winds and constituting a direct loss of timber production. However, more unusually and perhaps even more significant, damage caused by Yellow-tailed black cockatoos (Calyptorhynchus funereus) excavating in trees to extract the larvae for food can cause loss of up to 40% of trees as these additionally weakened trees are broken. The particular susceptibility of flooded gum (Eucalyptus grandis) to wood moth attack has deterred further plantings of this species in New South Wales in favour of less susceptible species. Other measures suggested have included mixed-species plantations, promotion of shrubby undergrowth in plantations to deter cockatoo attacks and avoiding plantings in areas where trees may become stressed through environmental conditions. Predation on wood-inhabiting moth larvae by parrots is evident also for the New Zealand Kaka (Nestor meridionalis), known to excavate the subcanopy tree Makomako (Aristotelia serrata, Elaeocarpaceae) in search of their preferred prey, larvae of Puriri moths (Aenetus virescens, Hepialidae: New Zealand’s largest moth with wingspan up to about 15 cm) (Yule and Burns 2020). Kaka also eat flowers and fruit and can decrease the production of both on Makomako trees.

References Austin AD, Yeates DK, Cassis G, Fletcher MJ, La Salle J et al (2004) Insects ‘down under’ – diversity, endemism and evolution of the Australian insect fauna: examples from select orders. Aust J Entomol 43:216–234 Beaumont LJ, Hughes L (2002) Potential changes in the distributions of latitudinally restricted Australian butterflies in response to climate change. Glob Chan Biol 8:954–971. https://doi.org/ 10.1046/j.1365-2486.2002.00490.x

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Britton DR (1994) Nutritional ecology of Chlenias spp. on an introduced conifer Pinus radiata D. Don. The effects of choosing a non-native host plant in Lepidoptera. Unpublished M.Sc. Thesis. La Trobe University, Melbourne Britton DR, New TR (2004) Exotic pine plantations and indigenous Lepidoptera in Australia. J Insect Conserv 8:263–274 Castedo-Dorado F, Lago-Parra G, Lombardero MJ, Liebhold AM, Alvarez-Taboada MF (2016) European gypsy moth (Lymantria dispar dispar L.) completes development and defoliates exotic pine plantations in Spain. N Z J For Sci 46:18. https://doi.org/10.1186/s40490-0160074-y Chadwick CE (1966) Investigations on Plutorectis caespitosae Oke (Lep. Psychidae) and Oncopera alpina Tindale (Lep. Hepialidae) in the Australian Alps. J Ent Soc Austr NSW 3: 5–29 Cunningham SA, Floyd RB, Weir TA (2005) Do Eucalyptus plantations host an insect community similar to remnant Eucalyptus forest? Austral Ecol 30:103–117 Green K (2010) The aestivation sites of Bogong moths, Agrotis infusa (Boosduval) (Lepidoptera: Noctuidae), in the Snowy Mountains and the projected effects of climate change. Aust Entomol 37:93–104 Habel JC, Segerer AH, Ulrich W, Schmitt T (2019) Succession matters: community shifts in moths over three decades increases multifunctionality in intermediate successional stages. Scientif Rep 9:5586 Henry SC, Kirkpatrick JB, McQuillan PB (2022) The half century impact of fire on invertebrates in fire-sensitive vegetation. Austral Ecol 47:590–602 Horak M, Mitchell A, Williams M (2020) National diagnostic protocol for Gypsy moths (Erebidae: Lymantriinae), focussing on L. dispar asiatica. Department of Agriculture and Water Resources, Canberra Hughes L (2011) Climate change and Australia: key vulnerable regions. Reg Environ Change 11 (Suppl 1):S189–S195 Kirkpatrick J, McDougall K, Hyde M (1995) Australia’s most threatened ecosystem: the southeastern lowland native grasslands. Surrey Beatty and Sons, Chipping Norton McQuillan PB (1999) The effect of changes in Tasmanian grasslands on the geometrid moth tribe Xanthorhoini (Geometridae: Larentiinae). In: Ponder W, Lunney D (eds) The other 99%. The conservation and biodiversity of invertebrates. Royal Zoological Society of New South Wales, Mosman, pp 121–128 McQuillan PB (2004) An overview of the Tasmanian geometrid moth fauna (Lepidoptera: Geometridae) and its conservation status. J Insect Conserv:209–220 Moir ML, Young DA (2022) Insects from the southwest Australia biodiversity hotspot: a barometer of diversity and threat status of nine host-dependent families across three orders. J Insect Conserv. https://doi.org/10.1007/s10841-022-00443-x Monteith G (2011) Giant wood moth and witchetty grubs. Fact Sheet. Queensland Museum, Brisbane New TR (2014) Insects, fire and conservation. Springer, Dordrecht Parida M, Hoffmann AA, Hill MP (2015) Climate change expected to drive habitat loss for two key herbivore species in an alpine environment. J Biogeogr 42:1210–1221 Patrick BH (2004) Conservation of New Zealand’s tussock grassland moth fauna. J Insect Conserv 8:199–208 Plant Health Australia (2009) Threat specific recovery plan. Gypsy moth Asian and European strains (Lymantria dispar dispar). Plant Health Australia, Canberra Shewring MP, Vaughan IP, Thomas RJ (2022) Moth biomass and diversity in coniferous plantation woodlands. For Ecol Manage 505:119881. https://doi.org/10.1016/j.forecol.2021.11.9881 Steinbauer MJ, McQuillan PB, Young CJ (2001) Life history and behavioural traits of Mnesampela privata that exacerbate population responses to eucalypt plantations: comparisons with Australian and outbreak species of geometrid from the northern hemisphere. Austral Ecol 26: 525–534

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Strauss SY (2001) Benefits and risks of biotic exchange between Eucalyptus plantations and native Australian forests. Austral Ecol 26:447–457 Thurman JH (2022) Beyond the pest: life history, ecology and ethnoentomology of the giant wood moth (Endoxyla cinereus). Austral Ecol 47:733–747 Ward MS, Simmonds JS, Reside AE, Watson JEM, Rhodes JR et al (2019) Lots of loss with little scrutiny: the attrition of habitat critical for threatened species in Australia. Conserv Sci Pract 2019:e117. https://doi.org/10.1111/cap2.117 Yeates DK, Bouchard P, Monteith GB (2002) Patterns and levels of endemism in the Australian wet tropics rainforest: evidence from flightless insects. Invertebr Syst 16:605–619 Yule KJ, Burns KC (2020) When an enemy of an enemy is not a friend: tri-tropic interactions between kaka, puriri moths and makomako trees. N Z J Ecol 44:3399. https://doi.org/10.20417/ nzjecol.44.4

Chapter 8

Moth Flagships in Australia: Focus on Single Taxa

8.1

Introduction

The very small number of moth species signalled formally as threatened or endangered in Australia and listed under Commonwealth or more local legislations (Table 8.1) is not in any way a realistic reflection of need, but largely the outcome of individual promotions, interests and concerns. Many ecologically restricted endemic groups are increasingly vulnerable as their restricted environments change. Conversely, many key areas and habitats of native moths are not represented by any listed species to signal their importance, and—despite the values of these few species as flagships—they simply indicate the greater needs that are so far not acknowledged formally. Most moths, even when suspected to be threatened, cannot yet be acknowledged in the terms needed for formal notice, because of inadequate knowledge. In contrast to the enviable United Kingdom scenario (p. 52) in which all moth species have been allocated some form of ‘conservation assessment status’ based on sound knowledge (even if still incomplete for many taxa), most Australian moths have not undergone any parallel investigation—and those species signalled for conservation interest are not any systematic selection from the wider fauna. Indeed, the sheer size of the fauna coupled with the low (but increasing!) numbers of moth enthusiasts effectively precludes any such comprehensive assessment, although generalised concerns are indeed widespread. For the approximately 1800 species of Lepidoptera in New Zealand, Hoare et al. (2017) assessed (or reassessed) the conservation status of 202 taxa, showing that 66 were ‘threatened’ and a further 77 were ‘at risk’. This assessment of slightly >10% of the fauna is anticipated to lead to a fuller assessment of New Zealand Lepidoptera. As an example of a more complete regional status assessment, Borges et al. (2018) presented conservation profiles for the 34 endemic moth species (representing 10 families) of the Azores, Portugal. Although 20 species were each known from at least four islands, nine were single-island endemics, and lack of recent records suggested that one (the geometrid Eupithecia ogilviata) was extinct. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2023 T. R. New, The Other Lepidoptera: Moth Conservation in Australia, https://doi.org/10.1007/978-3-031-32103-0_8

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Table 8.1 Numbers of moth species listed formally as of conservation interest in Australian legislations, at September 2022; states and territories noted by initial letters Legislation Environment Protection and Biodiversity Conservation Act 1999 (ACT) Nature Conservation Act 1980 (NSW) Biodiversity Conservation Act 2016 (NT) Territory Parks and Wildlife Conservation Act 2000 (Q) Nature Conservation Act 1992 (SA) National Parks and Wildlife Act 1972 (T) Threatened Species Protection Act 1995 (V) Flora and Fauna Guarantee Act 1988 (WA) Biodiversity Conservation Act 2016 Total moth species represented

No species 3 1 2 1 1 0 3 6 1 14

Several others are poorly known. Borges et al. believed that some were ‘in a critical conservation situation’ and threatened by pasture intensification, forestry and invasive species, as well as long-term impacts of habitat loss and climate changes. Even for that restricted fauna, considerable uncertainties persist, and further surveys and local inventories are needed. Those gaps are magnified in seeking priorities amongst endemic Australian moths, although the threats listed for the Azores moths generally are also very familiar to Australian workers. Nevertheless, only three moth taxa are currently (September 2022) listed under the Australian Environment Protection and Biodiversity Conservation Act 1999 (EPBC). These are (1) the Golden sun-moth, Synemon plana (Castniidae) which was previously listed as ‘Critically Endangered’ but has recently (December 2021) been revised to ‘Vulnerable’; (2) the Southern pink underwing, Phyllodes imperialis smithersi (Erebidae); and (3) the Antbed parrot moth, Trisyntopa scatophaga (Oecophoridae), both as ‘Endangered’. Several other moths have been signalled as potential candidates for ‘listing’ (Taylor et al. 2018), but it is accepted widely that most regions of Australia harbour moths of conservation importance and which would benefit from greater formal protection from threats and, in some instances, focused management to assure their well-being. A few other moths are indeed listed more locally, under state or territory legislations, and these are also included in Table 8.1, to give a national total of only 14 ‘listed’ species (at September 2022). As noted in the following species accounts, several species are listed under more than one legislation, but the Tasmanian Act acknowledges only three species of Geometridae, one (the Tunbridge looper, Chrysolarentia decisaria) as Endangered and the other two (Chevron looper, Amelora acontistica; Tasmanian Saltmarsh looper, Dasybela achroa) as Vulnerable. None is restricted to Tasmania, with A. acontistica perhaps the most widely distributed. C. decisaria is also found in Victoria and possibly threatened there, and D. achroa occurs also in saltmarshes in Victoria, where it is regarded as rare. Following attention to Synemon plana on the south-east mainland, a number of other endemic Castniidae with narrow ranges have also become conservation

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priorities. Several other moths were listed under Victoria’s ‘Advisory list’ of threatened invertebrates (DSE 2009), signalled from concerns over status or vulnerability and as possible candidates for later formal listing but there included without any legal status, as considered ‘near threatened’ and deserving further investigation. None has yet been investigated to further define conservation status, but New et al. (2012) noted that three (the Small whistling moth, Hecatesia exultans, Noctuidae; two species of Forester moths, Hestiochora rufiventris, H. tricolor, Zygaenidae) were known from very few records from limited areas of the state and were considered ‘near threatened’ (Hecatesia) or ‘data deficient’. H. tricolor may represent a complex of species (Tarmann 2004). Tarmann also ventured that Australian zygaenids are not endangered despite some of them indeed having small distributions and suggested that the existing protected area network may adequately conserve their habitats. Some historical legacy persists from mentions of Australian moths in earlier conservation literature. The pioneering IUCN Invertebrate Red Data Book (Wells et al. 1983), for example, noted three species of Tasmanian alpine geometrid moths (Acalyphes philorites, Dirce aesiodora (p. 169), D. oriplancta) as susceptible to fire and pastoral trampling. Respondents to a survey conducted by Hill and Michaelis (1988), seeking suggestions of insects actually or potentially threatened in Australia, provided names from three families: Anthelidae (several species of Pterolocera in the southeast), Geometridae (the above and two further species of Dirce from Tasmania) and Hepialidae [Aenetus blackburni, Zelotypia stacyi (p. 160)]. Thus, very few moth species have gained an individual informed appreciation of their conservation need in Australia: in comparison with butterflies, very few moths can be regarded as in any way ‘flagship species’ in capturing public interest and concern. Most microlepidoptera, in particular, remain unsuitable as candidates for species-focused conservation, and the only practical option for sustaining these is to ensure that the ecosystems on which they depend are protected (Franklin 1993). As for the Bogong moth (p. 171), that interest may focus primarily on the wider consequences of moth decline rather than concern for the moth itself: it is perhaps inevitable that the fate of the iconic Mountain pygmy possum (Burramys parvus) through being deprived of a major dietary component will garner more public and political sympathy than that of the Bogong moth on which it feeds. Nevertheless, the interdependence integral to this case is a significant lesson on the functional importance of conserving such food supplies for threatened vertebrates. That a single moth species can constitute the major food on which the survival of an endemic marsupial depends is a powerful message on the functional importance of an insect species and the possible consequences of its loss.

8.2

Selecting and Designating Priority Species

In order for ‘flagship species’ to become effective as ambassadors, their significance and values must be acknowledged and publicised widely, with the engagement of members of the scientific community with the media and wider public from a basis

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Table 8.2 Components of information suggested for inclusion in a species dossier for the nomination of a flagship insect or allied invertebrate species in Australia (Taylor et al. 2018) Attribute Taxonomy Description Conservation status Distribution Biology Ecology Key threatening processes Scientific and/or social value Community engagement References

Information required (a) Scientific name, author, date, synonymies; (b) higher classification (order, family); (c) common name (provide one if not available) (a) Brief description providing diagnostic features for identification; (b) similar species; (c) image of species Under which conservation schedule or act, if known or evaluated (a) IBRA region; (b) spatial map; (c) breeding habitat or ecological community; (d) land tenure; (e) occupancy (sites/areas occupied) Life history, seasonality, life cycle Ecological interactions (food plants, hosts, predators) (a) Threats; (b) evidence of decline E.g. relictual, phylogenetically distinct, keystone species, aesthetic, mediagenic, cultural, entomophagy, biophilia, economic, ecotourism (a) Identify stakeholders; (b) management plan; (c) recovery plan Cite all relevant information

of sound documentation (Taylor et al. 2018). Whether the species are primarily threatened (Ward’s atlas moth, some Castniidae), iconic (Bogong moth) or of scientific interest (Enigma moth), publicity from established knowledge and concern continues to be influential and create/broaden conservation concern and advocacy within the human community. In selecting further flagship insect species, Taylor et al. emphasised the relevance of using practical and achievable criteria that can engage local community interest. Criteria suggested included visual impact, ecological importance, scientific and/or social values and ‘above all, resonance with the general public’. Further engagement can be facilitated by advice on practical conservation measures and why these are needed. Information that could be included constructively in a dossier on each species to be considered for flagship status was grouped into 10 key categories (Table 8.2; Taylor et al. 2018). These extend far beyond the more conventional ‘risk of extinction’ appraisals of formal conservation status that form the basis of most conservation listings of species. They largely echo earlier iterations of flagship features, amongst which Bowen-Jones and Entwistle (2002) noted that ‘traditional knowledge’ may be a valuable source of information and together with ‘cultural significance’ provide opportunities for expanding interest and garnering support. Formal designation (‘listing’) of individual moth taxa as in some way threatened and (in principle) according to them conservation priority has occurred for very few—certainly only a tiny proportion of taxa that are likely to merit such notice and in some cases these are drawn from far longer ‘Red Lists’ of threatened species that have been evaluated for risk of extinction based on the IUCN Red Data Book criteria (Fig. 8.1) or other standardised criteria. In general, the species listed are those with the highest risk (critically endangered or endangered), so with the most parlous

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Fig. 8.1 Hierarchy of IUCN Red List categories, showing the groups to which assessed species may be allocated to reflect their status, with risk of extinction increasing towards the top of the page (based on the figure from IUCN 2012) For moths and most other insects, a great majority of taxa remain Not Evaluated or Data Deficient Table 8.3 Conservation categories proposed for Scottish moths (Bland and Young 1996) X 1A 1B 1C 2A 2B 3

Species for which any action is probably too late Scottish species/subspecies with very restricted distribution and potentially or actually in urgent need of protection Scottish species in urgent need of research into biology and/or distribution: potentially in need of protection Scottish species for which better distribution data are needed but which appear to be reasonably widespread and secure British species of very limited distribution with colonies in Scotland in urgent need of protection British species with colonies in Scotland, in urgent need of research into biology and/or distribution Species on edge of the range in Scotland, not needing immediate protection

existence and for which conservation is urgent to prevent their demise. Those species may also be the most poorly understood, so conservation measures needed become difficult to hone beyond generalities such as habitat/site protection, as the most vital basis for further investigation. Many such species are brought to notice only after severe declines or population losses have been detected. The difficulties of setting conservation priorities were noted for Scottish moths, for which Bland and Young (1996) recognised a category of ‘Species for which any action is probably too late’, because they were presumed extinct. Their wider categories for conservation interest (Table 8.3), from a fauna far better documented than Australia’s moths, indicate a

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knowledge-based hierarchy from which major needs and priorities are clear. More informal information can also contribute to assessing conservation status but, again, may be difficult to pursue in Australia. Thus, in the Czech Republic, Red List assessments were augmented by the construction of a ‘commonness index’, in which four national moth experts ranked all moth species into four categories, as ‘extremely rare’, ‘rather rare’, ‘rather common’ and ‘extremely common’ (Potocky et al. 2018). The mean values from these responses were treated as the species’ commonness index, affording some consensus over selecting the most needy species and the magnitude (number of needy species) of concern. Formal listing under conservation legislation (in Australia under the Commonwealth’s Environment Protection and Biodiversity Conservation Act or one or more of the range of state/territory jurisdictions) is essentially a prerequisite for acceptance of conservation interest and possible need. Nomination for listing demands appraisal of the species’ vulnerability, based on trends in distribution and population size in relation to projected fate and actual or potential threats, in the perspective of the best available biological information on the subject taxon. The widely used IUCN criteria (above) are recognised widely to have serious shortcomings for invertebrates (Cardoso et al. 2011). Many modifications have been suggested to compensate for the lack of fundamental information on which those criteria rest—but commonly produce the outcome that many insects are necessarily categorised initially as ‘Data Deficient’. Moths are no exception: other than in the most well-studied faunas, the lack of basic distributional and biological information needed to mount a convincing case for endangerment detracts effectively from credibility. For most Australian examples noted here, the nominations for listing have rested largely on supposed rarity and narrow distributions, derived from specimen and locality records and the best opinions of informed naturalists, together with perceived or anticipated threats to such key localities or habitats. For many, little or no biological information is initially available, and lack of survey inevitably renders their true distribution incompletely recorded. Conservation concern is considered a wise precaution for many species pending further information and survey that can help to categorise them more reliably. A statement accompanying descriptions of localised new species of Oxycanus (Hepialidae) (and echoed by similar sentiments in numerous other taxonomic papers) as ‘Concerns are raised about the conservation status of all three new species due to few or localised distribution records’ (Beaver et al. 2020) endorses need for further exploration of ranges of many other taxa. Implications for population loss or decline (and risk of extinction) are related mainly to the loss or degradation of habitats from a variety of external influences, but without reliable trend data for any extended period. Cardoso et al. (2011) argued that the criteria for ranking extinction risk should be both ‘feasible’ (the required data should be obtainable for reasonable effort) and ‘adequate’ (the criteria enabling realistic ranking). Even for members of the best-known moth groups in Australia, allocation of any firm conservation status remains difficult. The considerable recent attention to sun-moths (Castniidae) has done much to demonstrate the problems that arise and that a species’ status may change as more complete studies and surveys are undertaken—as for the Golden sun-moth, Synemon plana (p. 162). More generally,

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Table 8.4 Criteria for threat evaluation for Sphingidae of Paraguay, based on distributions across ecoregions and political departments (see text), with the number of species (overall n = 100) allocated to each category (Smith 2022) Critically endangered Endangered Vulnerable Near threatened Least concern Data deficient

Occurs in only 1 category A ecoregion and only I Paraguayan political department, outside of the protected areas system; n = 2 Occurs in only 1 category A ecoregion and 3 Paraguayan political departments; n = 13 Occurs in 1 category A and I category B ecoregion, or 2 category A ecoregions and >5 Paraguayan political departments; n = 12 Occurs in 3 or more category A or B ecoregions; n = 63 Known from only one specimen; or a species with issues surrounding records that suggest the species could be more common than the data suggest; lack of data from neighbouring regions and few local ecological data lead to liberal use of this category; n = 7

at any given site, the only information to hand relates to ‘presence/absence’, with the latter difficult to confirm without a reasonably comprehensive survey. A comment on the hawk moths of Paraguay transfers easily to many moth groups in Australia: ‘Given the limited and geographically-biased sampling that has been performed to date, I considered it premature to consider a lack of modern records as indicative of local extinction’ (Smith 2022). In some ways parallel to Australia’s bioregions, Smith classified Paraguay’s six major ecoregions as (A) those of critical conservation concern and (B) those of secondary conservation concern, so that threat level to sphingids was allocated as in Table 8.4, with the extent of distribution and numbers of records linked tentatively with habitat associations. Australia’s Sphingidae have not yet aroused focused conservation concern: despite some of these iconic species being known from relatively few records, Moulds et al. (2020) considered that no Australian hawk moths were ‘truly rare in nature’. Notwithstanding the ecological representation to be gained by selecting focal insect species from each major bioregion (Taylor et al. 2018), the nomination of any moth species for priority conservation attention almost inevitably means that other equally deserving candidates are passed over—but even in the best-known faunas the criteria used for selection may be difficult to define fully. For the United Kingdom, Parsons (2004) noted that knowledge of many species rendered it difficult to apply rigid criteria under the Biodiversity Action Plan (BAP) for which 122 moth species were initially listed. Those species were selected on five broad criteria as (1) being threatened endemic or other globally threatened species; (2) species for which the United Kingdom has >25% of the world or appropriate biogeographical population; (3) species for which numbers or range have declined by >25% in the last 25 years; (4) in some cases when the species is found in fewer than 15 survey units (in the United Kingdom, of 10 × 10 km squares); and (5) species listed in a stated range of other Habitat Directives or other regulatory documents.

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Contrary to much public presumption, ‘listing’ itself is not ‘conservation’ but a valuable first step of acknowledging that conservation may be needed, and sometimes facilitating its occurrence by nominal priority for allocation of scarce conservation resources, and to stimulate further evaluation and study. Listing is thereby a responsible process, because it can effectively deprive equally deserving but unlisted species of that support. It is, however, often viewed with suspicion by hobbyists and others whose interests may be alienated by preventing access to specimens or sites where the taxon occurs and, in some cases, with fears of prosecution for transgressions. Those sentiments were included by Sands (1999) in noting that listing in Australia is (1) a primary objective for conservation authorities; (2) whether by state or commonwealth may be appropriate or contentious; (3) does not automatically protect the habitats of threatened species; (4) seriously limits collecting or handling of specimens; (5) may be difficult to modify once made law; (6) has discouraged amateur contributions and thus limited recovery actions; and (7) influences decisions for funding recovery plans. For poorly known taxa—with most listed insects amongst them—uncertainties over status and threats can also erode confidence and lead to loss of credibility. The formal obligations from listing species differ somewhat across Commonwealth and the various state/territory legislations in Australia and may or may not eventuate. An ‘Action Plan’ or ‘Management Plan’, either as part of the nomination process or prepared as an obligation from the listing or for further review, summarises the conservation dilemma and needs and what actions are needed, in as much detail as possible. For all moths considered so far in Australia, those recommendations have included a strong component of the need for further survey and basic documentation. In practice, the production of such a plan may be at the discretion of the relevant administrators and advice obtained. For the Antbed parrot moth (p. 165), for example, a separate plan was not considered necessary because the advice accompanying appraisal for listing as endangered included substantial information on threats and management needs. However, the contents of the UK plans are equally relevant elsewhere, and the essence of those foundation documents flows clearly to Australian needs. A standardised format for any such Plan (1) allows comparisons across taxa; (2) demonstrates the major gaps in information and understanding; (3) reveals the major concerns, either individual or common/overlapping with other taxa, and how these may be addressed and (4) may help to define and prioritise actions for protection and management, with indications of their costs and complexity/feasibility. Again, the greater experiences from initiatives such as the United Kingdom BAP (Parsons 2004) suggest a format that has incorporated the major needs of species, but also includes provision for a less comprehensive ‘Species Statement Plan’ as an abbreviated Action Plan in which the section on actions is reduced—commonly to confirming the need for monitoring as the only action. Each UK moth Action Plan contains several sections: (1) introduction, with the discussion of the current status and a summary of the species’ ecology, accompanied by a distribution map; (2) the reasons (actual and perceived) for loss or decline, with the summary of current conservation actions; (3) objectives and biological targets, such as monitoring

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populations and range; and (4) responsible agencies for each action, including policy, protection, management, research, monitoring, communications and publicity. The last of these is often clear in Australia, through the relevant Department of each state or territory jurisdiction, but this allocation of responsibility may not gain high priority, not least through lack of personnel and resources: some such departments lack any permanent entomologist or wider invertebrate specialist on their core staff, with this recognised widely as a significant hindrance to insect conservation (Yen and Butcher 1997). The UK plans are coordinated through the organisation ‘Butterfly Conservation’, as an ‘umbrella lead’ with a priority aim of providing a coordinated approach to the conservation of the UK’s BAP priority moths and using limited resources for the greatest collective benefit. Emphasis at the time of Parsons’ (2004) account was largely on macromoths, but more recently some microlepidoptera have been incorporated as knowledge accumulates. No such coordination of projects currently functions in Australia, but recent revisions of the Commonwealth Environment Protection and Biodiversity Conservation Act may lead to more effective collaborations. In North America and Europe, the long traditions of lepidopterology and conservation concern have generally enabled reasonably detailed protocols to be proposed, but these do not overcome the logistic impediments involved in the high expense and scientific investment in species-level conservation projects. Likewise, requirements for formal periodic review of progress are sometimes difficult to fulfil. Any ‘listing’ has the potential to foster interest and obviate impacts of changes or loss—itself integral to practical conservation. The scope and content of ‘listing proposals’ vary greatly across different legislations, together with the criteria used for evaluation. A recent proposal for declaration of endangered species status for a North American saturniid, the Bogbean buckmoth, Hemileuca maia menyanthevora (or H. iroquois), under the United States Endangered Species Act 1973 (USFWS 2021), for example, was developed from a substantial amount of basic knowledge and awareness of concern and foreshadowed by comprehensive appraisals of the moth in both the United States and Canada. Adults are short-lived and do not feed. The moth is a very local member of a complex of species, amongst which taxonomic issues complicate conservation efforts (Schowalter and Ring 2017), with wide concerns over habitat loss, fire impacts and possible alien parasitoid attack (p. 101). The univoltine Bogbean buck moth is known to occur only in Oswego County, New York, and Ontario, Canada, and was signalled earlier for conservation significance in both countries; it was recommended for listing in Canada by COSEWIG (2009) and listed as endangered in New York far earlier, in 1999. It is known in New York only from six sites on the south-east shore of Lake Ontario and in Canada from four sites (two pairs separated by about 50 km, with each pair of sites considered a ‘population’) in eastern Ontario (Fig. 8.2), but with some historical populations extirpated in both countries. USFWS (2021) knew of five extant populations. As a large, conspicuous diurnal moth of a family highly sought by collectors, it is believed widely that searches throughout both regions have been sufficiently comprehensive to claim that further populations are unlikely to be discovered. Conservation thus focuses on the

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Fig. 8.2 Known distribution of the Bogbean buckmoth, Hemileuca sp., in Canada (Ontario) and the United States (New York); extant populations shown by black spot (after COSEWIG 2009)

few occupied open fen sites in which the larval food plant (Menyanthes trifoliata, Menyanthaceae) grows in shallow water or on bog edges and across which the total area occupied by the moth is 70%) Which qualifiers apply to this taxon? Some commonly used qualifiers are listed as follows: conservation-dependent (presently relies on conservation); data poor size (lacking information about population size for a robust assessment); data poor trend (lacking information about population trend for a robust assessment); island endemic (restricted to single island or island group, excluding major NZ islands); one location (a distinct area in which a single event could easily affect all individuals): range-restricted (confined to specific habitat types: not used if the taxon is one location); recruitment failure (population may appear to be stable but new generations not being produced or do not reach maturity)

measures (Geyle et al. 2021; Sands and New 2002), and there is a need for far greater such appraisal for moths and to seek advice on the most deserving candidates. Plans to update the 2015 data used to assess the conservation status of New Zealand Lepidoptera (Hoare et al. 2017) included a call for advice (DOC 2019) about any new information or potential changes in status to be considered against the now well-tested New Zealand Threat Classification System of Townsend et al. (2008). That manual contains a series of ‘qualifiers’ to augment a more formal appraisal of the taxon, and DOC (2019) requested the information summarised in Table 10.2. Despite its inadequacies, some form of ‘conservation plan’ for a species, group of species, habitat, site, or to alleviate a defined threat is the broadest basis for advancement. Validity (reflecting current knowledge) and practicality (depending on context and resources available) clearly vary enormously and, as discussed in Chap. 8, may have significant gaps in coverage pending further study and survey— which then become important components of understanding conservation need. Those plans vary enormously in scale and scope—again referring to designated flagship species noted earlier, for the relatively sedentary Golden sun-moth (p. 162), conservation activities have tended to concentrate on individual grassland sites, so is ’site-based’ whilst implicitly seeking the unity of practice across different such patches throughout the moth’s range. In the contrast the vast breeding range of the Bogong moth (p. 171) in southern Australia and across which the moth is vulnerable

10.1

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implies the need for a range-wide consideration of conservation need, together with the aestivation sites so critical to the moth’s biology. At any level, and embracing all cases for ‘listing’ or plans for practical conservation, a continuing dilemma (not in any way confined to moths) is communicating the importance of ‘uncertainty’ arising from incomplete knowledge to managers and decision-makers whose actions may determine the fate of poorly known species and the places and resources on which it depends. Examples in the last two chapters demonstrate the incidence of such uncertainties and unknowns of current occurrence, trends in abundance and distribution, resources needed to sustain a species, and influences of present and projected threats on species and wider moth assemblages and diversity. Some consensus may be forthcoming through modelling exercises using the best available information, but such extrapolations are not always convincing. One relevant case is a Bayesian Belief Network Model analysis of Golden sun-moth trends in urban fringe areas in southern Australia (Mata et al. 2017), in which a workshop team of people familiar with the moth (‘experts’) and advisors assembled their experiences and thoughts on understanding how population viability was determined. The group examined the nature of cause–effect relationships between the various factors and attempted to assess expectations of moth population viability in response to contributions of management actions in nearurban environments. The participants generally agreed that the most important variables affecting moth populations were adult survival, the extent of bare ground cover and cover of resource plants—but opinions on the extent of influence of these and other variables themselves varied considerably. The basis for this conceptual model (Fig. 10.1) involved both ‘conventional management’ and the more innovative ‘biodiversity sensitive urban design’ measures. Such general conservation recommendations are widely considered responsible, if interim, as a basis for advancing protocols—as adopted widely elsewhere in status assessments and subsequent management proposals and plans. The main reason for the designation of the North American Island tiger moth (Grammia complicata, Erebidae, largely endemic to Canada, but with one record from Washington State) as threatened was a combination of small distribution with few populations, with an embracing comment on habitat loss and degradation ‘due to ongoing residential and commercial development, recreational activities, invasive or non-native species, and vegetation succession that has changed due to disruption of former fire regimes’ (COSEWIG 2013). The principles of such a statement transfer easily to many Australian moths and their environments, spanning a range of broad threats, as is the ensuing comment that relevant land managers are aware of records within protected areas, but management activities are yet to be addressed—so that trajectories of loss or decline of the tiger moth could only be inferred. Protection of the site or few sites on which most listed species are known or suspected to occur may be formally ordained and, in practice, be the most significant initial conservation measure needed. However, the security of a site is simply the major prelude to management, if needed, and determining the nature and scope of that management rests on the knowledge of the species and its vulnerability. Clearly, simply ‘locking up’ a sensitive site without targeted management may not allow the

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Fig. 10.1 Conceptual model of web of key variables affecting changes in Golden sun-moth (Synemon plana) populations, with the two categories of ‘conventional management’ nodes (shaded) and ‘biodiversity sensitive urban design’ (open) inputs differentiated (after Mata et al. 2017)

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suitable conditions for a specialised moth to persist—and the optimal conditions needed may not always be known. In an extreme case, the presence of the target moth (as impetus for site preservation) may simply reflect that it is ‘hanging on’ in marginal or suboptimal conditions, rather than thriving, and uninformed management could hasten its demise through deliberately emulating those poor circumstances. Promotion of any such species as a ‘flagship’ for wider conservation concerns rests on (1) factual evidence of conservation need based on defined threats and objective information—wherever possible with some IUCN status category to affirm priority concern, and (2) a wider picture of the species’ role or significance, interest, idiosyncrasies and other features that may garner interest and support. ‘Local pride’ has been prominent in gaining support for many butterflies, perhaps involving local interest groups to promote the conservation of the species itself, its host site(s) and its wider interest. The Golden sun-moth (p. 162) has become the predominant insect flagship for threatened native grasslands in the southeast, with its strategic (and sometimes controversial) roles in helping to protect those grasslands from developments widely publicised, and participation in many conservation cases, its presence supporting the protection of many periurban grassland remnants and commemorations such as statues and a children’s playground in outer Melbourne modelled on the moth (see New 2015). It has also been instrumental in the development of wider strategies such as habitat offsets to compensate for lost sites. The most basic factors that restrict or facilitate practical conservation interest in any single moth species include the following: 1. Need for clear and unambiguous recognition and identification of the focal taxon, ideally enabling reliable and consistent identification (at least of adults) when encountered by non-specialists. A formal binomial name facilitates seeking any published information and communication with authority: in the absence of a binomial, a consistent epithet such as ‘Genus sp. XX’ may be useful. 2. Lack of information on early stages (which may not be recognisable) or many aspects of the basic life cycle. Many records of species of interest are from adult specimens alone, with little if any information on larval food plants, voltinism, seasonality (other than flight season deduced from adult records) and behaviour. 3. Lack of information on the environmental conditions and resources required by the species, and their vulnerability to imposed changes. Without this, much management may be pursued only in rather general terms. 4. Lack of information on distribution at local to regional scales. 5. Scarcity of funding, interest and expertise to address any of these factors constructively and to formulate a sound conservation status assessment and management plan. In essence, community involvement in moth species conservation is largely restricted to those taxa that are distinctive and accessible for evaluation and study and for which informed advice is available to provide help. The wider perspective of conserving moth assemblages, mainly through the protection of key habitats, is the only realistic/idealistic option for most others and must be pursued in the arena of

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competing and conflicting pressures for land use and change. Thus, although assumed widely that designated national parks in Australia have a primary conservation purpose, many of those areas are also used for recreation (including developments for increased vehicle access and parking, accommodation and services), grazing, extractive mining and other activities that may increase anthropogenic threats to resident biota. Multiple uses are clearly important, as societal expectation, but protection of the most sensitive areas becomes correspondingly more difficult and uncertain as these proliferate. More generally, many of the world’s protected areas have been designated with little or no regard for insects, which are thereby ‘passengers’ in arenas selected primarily to protect designated vertebrates or plants, or unusual communities or ecological/geographical features. Most of the few exceptions focus on butterflies, Odonata, or wider ‘biodiversity’—but many such areas are likely to share the reality that ‘protected areas have become a last refuge from proliferating human-induced threats’ (Chowdhury et al. 2022). Most studies of insects in protected areas have focused on surveys to establish richness and representativeness, and the presence of notable species, rather than on how the management of the areas can attenuate threats. Only 9% of the 1590 studies of insects in protected areas examined by Chowdhury et al. focused on threats and only 3% on the effectiveness of the areas for conservation. However, even without specific management, simply designating protected areas can alleviate much threat—in Australia not least through halting direct habitat destruction. This echoes the roles of insects as passengers and is far from imposing deliberate practical conservation management. Chowdhury et al. (2022) proposed a four-stage agenda to increase the effectiveness of protected areas for insect conservation as (1) integrating insects into management plans; (2) strategically designate new protected areas for insects; (3) designing wider insect conservation initiatives beyond protected areas; and (4) invest in insect monitoring and research. Moths are suitable foci for all these endeavours in Australia and for focusing actions and priorities. For the last, targeted field surveys, biodiversity assessments and long-term systematic surveys were all noted as paths to improvement, in part through citizen science interests (p. 185). Not all threats in protected areas are amenable to easy management, and some will assuredly persist. Nevertheless, as Kearney et al. (2020) reaffirmed, ‘Australia’s National Reserve System is the country’s most important investment in biodiversity conservation’. Across all taxa of Australian threatened species, many (815 of 1555) required threat management that could not be achieved by protected areas alone, so management that neglected the wider landscape would not benefit many species. Designation of new reserves specifically for insect conservation is unusual in Australia, but exercises such as the inventories discussed earlier are important demonstrations of the worth of existing protected areas and the values of protecting them further for the conservation of little-known biodiversity and, wherever possible, seeking to expand the extent and number of reserves for more effective coverage. The designation of a ‘sun-moth reserve’ in Victoria—the first such reserve for moths in the state—attracted considerable attention, not least as the only place where two designated threatened species of Synemon co-occurred (Douglas 2004) and the

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only known site where one of these (the ‘Nhill Morph’ of Synemon selene) is known and because of the marked change of land purpose and tenure for this step to be taken. Douglas believed that this survival may be because the area had never been ploughed or artificially fertilised—a circumstance he regarded as ‘extraordinary’. The land, a patch of only 4.5 ha, had been divided into 21 allotments and sold to 10 seperate purchasers, and some building plans were well advanced. The local shire council accepted the importance of the potential reserve and agreed to re-zone the land if the current owners would agree to sell or exchange their blocks. Considerable funding for purchase was raised, and the Nhill Sun-Moth Reserve was declared officially in 2003 (Douglas 2004), with the area placed under a formal environmental overlay that prevented further development or other intrusion. The great variety of Australian ecosystems that each support moths (and other insects) that are not known elsewhere and are presumed to be specific to the particular conditions and resources they provide emphasises the needs for these to be sustained wherever possible. Three related components of management contribute to this, as ‘habitat protection’, ‘habitat creation’ and ‘habitat restoration’. Each may target particular moth species—for which it is necessary to be aware of the specific resource needs—or wider diversity, with the presumption that greater availability of key host plant species and greater floristic variety and heterogeneity may respectively foster key focal taxa and local assemblage diversity of this predominant herbivore group. These components are not wholly distinct: simply ‘locking up’ an area as a protected reserve does not obviate the needs for continuing management, for example, to create or restore early successional stages as these are lost. Many of the general principles relevant to the practical conservation of Australian moths (and other insects) have been exemplified from cases elsewhere in the world and discussed in earlier chapters. They include the following: 1. Many key habitats and vegetation types in Australia have undergone immense change, and the documented historical background of moth faunas against which to measure the impacts of those changes is incomplete or wholly lacking. Concerns arise from direct losses of habitats and the numerous additional anthropogenic stressors, including influences of climate change. 2. Many of those key habitats now occur only as small remnants of their former extent and may need protection against further erosion and loss. Increasing the extent and representativeness of the protected area network is universally important for moths and much other insect diversity. 3. That a moth or a defined assemblage is known from a recognised ‘protected area’ does not guarantee its future safety, for which proactive management may be needed. 4. Any moth habitat is embedded within a wider and more variable landscape, whose features can influence the habitat of concern. Small or isolated habitat patches may need management to reduce edge effects (such as by ‘buffer zones’ or softening of margins) and to monitor unwanted intrusions from outside.

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5. The diversity of moth assemblages changes with successional stages, and restoration or regeneration of early vegetation may be necessary for many species to persist. 6. Not all moth species in any survey will be identifiable reliably, and cross-site and cross-survey comparisons may need very careful interpretation to avoid confusions, recognising that very similar and closely related moth species may have different biology and respond differently to impose changes. 7. Different functional guilds (such as feeding groups) of moths respond differently to habitat changes, and this may not become evident from simple measures of species richness. 8. Use of changes in moth assemblages as ‘indicators’ or ‘predictors’ of environmental impacts is attractive, but may depend heavily on local environmental conditions, contexts and the taxa examined. 9. Management of intensively altered environments such as agricultural, forestry and urban ecosystems to conserve moths involves a combination of (1) promoting and enhancing natural features and connectivity and (2) reducing and preventing further threats. 10. Heterogeneity and vegetational diversity are important associates of moth diversity, and management to foster these may be beneficial. Much moth conservation activity necessarily focuses on vegetation variety and condition or the presence of particular plant species. 11. Mosaic management promoting varied conditions across the landscape is generally preferable to large-scale uniform management that does not provide spatial habitat variety. 12. Reliance on single focal scarce or threatened species as ‘conservation flagships’ is an important component of promoting and undertaking moth conservation, but wider considerations to gain broader benefits to local faunas are also needed. 13. Public perceptions of moths are not always supportive of conservation, and activities such as (1) enhancing appreciation of moth importance and diversity through education and (2) promoting citizen science through community awareness are integral to much successful conservation. 14. Increasing formal awareness of, and attention to, moth conservation needs (such as by increased representation on ‘protected species lists’) and increasing their formal profile in conservation decisions and recommendations can have benefits such as (1) advocacy for conservation action and (2) complementing any conservation efforts based mainly on other taxa, whilst also demonstrating and emphasising their richness, ecological variety, functional importance in ecosystems and vulnerability. This list is neither complete nor prescriptive, but contributes a framework of considerations against which needs and actions in any moth conservation exercise may be assessed and ranked. Any such exercise involves a variety of ‘stakeholders’, broadly those interest groups whose inputs are valid and mixed, but whose viewpoints may need to be harmonised for a successful outcome. The local environment may strongly influence the variety of stakeholders—not in any way restricted to

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Habitat Management Issues

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moths, the interests and priorities based on urban, agricultural, forest or grassland ecosystems and their stressors may differ markedly and in some cases have considerable economic components.

10.2

Habitat Management Issues

Much management of degraded sites and improvement of others includes some form of ‘restoration’. Restoration involves enhancement and reestablishment of key resources on sites that are—or can be—protected sufficiently (and threats mitigated as far as possible) to ensure that the effort will not be futile. A long-term view— idealistic and usually impracticable—may encompass the designation and preparation of sites for future colonisation or occupancy along environmental gradients to cater for anticipated pressures imposed by climate change and recognise that some currently unsuitable areas may become significant in the future. Any restoration approach targeting moths usually involves increasing the availability of larval food plants in suitable environments, perhaps augmented by enhanced suitable nectar sources for adults. Those tasks may also involve considerable site preparation through steps such as ground preparation and elimination of alien weeds and provision for continuing on-site maintenance and security, perhaps involving the land purchase or change of tenure. In part, restoration seeks to ‘short-circuit’ natural successional processes towards the reestablishment of wooded environments by the planting of selected woody vegetation (Kitching et al. 2000) or enhancing early stages of succession and countering their loss as succession proceeds. Terms such as ‘rehabilitation’ and ‘rejuvenation’ of habitats largely overlap, as does the more extensive ‘habitat creation’. The last, essentially an extreme form of restoration, may be needed to transform heavily alienated landscapes such as intensive agricultural areas or plantations of alien trees towards their (often incompletely documented) parental condition or even towards completely new habitat patches. Possible guidance on the targets needed in such long-term management may be available from historical records and from the fauna of the nearest available more natural remnants, using the latter as a ‘benchmark’ guide to key attributes of a desirable restoration outcome. Initial comparisons of the moth assemblages by systematic sampling in the benchmark area and the target area may both indicate the magnitude of the task and disclose possible foci of notable taxa that should be accorded priority. More focused steps may entail restoring more specific resources for individual significant moth species to facilitate natural colonisation or future translocations, whilst also ensuring the security of the site and encouraging increased floristic diversity. The Golden sun-moth in Australia is an informative example, and the importance of restoring processes and interactions—in addition to simply the structural components (species)—was emphasised in a New Zealand study of a monophagous coleophorid moth (referred to ‘Batrachedra’, pending more definitive description)

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(Watts and Didham 2006), for which restoration focused on small (5 m diameter) raised islands in peat bogs, with the moths colonising food plants introduced there. The broader aims of restoring diversity largely focus on suitable heterogeneity and accessibility. For moths and other herbivores, any habitat restoration may be beneficial but, as Tallamy and Shropshire (2009) soberingly commented ‘To create landscapes without knowledge of how the plants in those landscapes support insects, and thus insectivores, is to continue the practices that have decimated animal populations in managed ecosystems over the past century’. The ‘leave alone’ approach to restoration, exemplified by much farmland abandonment in Europe, even perhaps accompanied by judicious management to reduce continuing threats— such as by suppressing alien plants—may, despite lack of greater focus, benefit local biodiversity by deterring further purposeful habitat loss. Logistic restrictions can dictate that such a ‘field of dreams approach’ (i.e. leave it alone and they will come!) may indeed contribute to the conservation of mobile species. Most restoration exercises that lack precise faunistic targets continue to focus on native vegetation as the major axis for change and use local provenance stocks for this to avoid any genetic contamination. Monitoring of restoration processes for moths, especially beyond single species, is unusual in Australia, and baseline information for comparison is usually uncertain. Rather than the (desirable) longterm surveys needed to track outcomes of individual restoration exercises, values of moth assemblages as indicators of restoration change have been explored through comparative surveys of moths at different stages, from the baseline of unrestored land through restoration stages to remnants of the target condition. The principle was displayed by a pilot study on the Cumberland Plain Woodland, an endangered ecological community on the outskirts of Sydney, New South Wales (Lomov et al. 2006). Restoration of an area of degraded plain commenced in 1992, when parts of the abandoned farmland were progressively replanted with native trees and shrubs. Management involved weed control (by herbicides and slashing), tube stock plantings (using 26 species of local native trees and shrubs), fire protection, and fencing restored areas to exclude grazing stock. Moths and butterflies were sampled from four site treatments along the restoration sequence (untreated farmland, two stages of revegetation, woodland remnants). A high proportion of moth species (57% of 119 species, with only those species >5 mm in size evaluated) were singletons. Restoration management increased the diversity of the moth assemblages, but their composition remained similar to those on the unrestored sites. Uncertainty over the status of the numerous ‘uncommon’ species precluded greater analysis and prediction of future trends as succession occurs and that uncertainty extends to any appraisals of moth richness as an indicator of restoration in Australia. Simply because butterflies are better known and less diverse, Lomov et al. suggested that they might be the better focus in monitoring. Perhaps paralleling likely trends in Australia’s future moth conservation, and a number of informative studies on grassland, forest and wetland restoration elsewhere have given useful pointers to responses of moths. However, some comparative studies are difficult to evaluate fully because restoration habitats may converge with the parental conditions, but differ from them either in form and function or

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from the influence of long-term ‘legacy effects’ (such as changed soil texture or chemistry, and water chemistry) from the pre-restoration anthropogenic ecosystem. The initial definition of a ‘regional species pool’ of moths can theoretically define the limit of species variety that may contribute to (and be affected by) change. Within that pool, the fate of any individual species reflects its dispersal ability and the availability of critical resources that may or may not be known or considered carefully in a restoration exercise. Each distinct habitat harbours a local selection of the regional species pool. In comparing moths of prairie remnants and restored prairies in Iowa, United States, Summerville et al. (2006) found that species moving into restored prairie from the regional pool tended to be multivoltine, had long flight periods, had feeding preference for legumes (but not other forbs) and whilst regionally abundant were also relatively small in size. Species traits and habitat features interact in the outcome, and one suggested strategy from that study was that restoring Lepidoptera on tallgrass prairies may involve plantings adjacent to habitat remnants. In a rather different context, of moth outcomes from creating woodlands on agricultural land in Scotland, Fuentes-Montemayor et al. (2015) pointed out that many created woodlands differed considerably from the model semi-natural woodlands, in having lower tree species richness, a lower proportion of native trees, tree basal cover and amount of understorey, and higher tree densities and canopy cover. They were thus predicted to have lower moth richness and abundance, but, as in the North American prairies, above, the actual differences depended on the habitat specificity and dispersal of the different taxa and with implications that the created woodlands were more encouraging for generalists and dispersal-restricted species. In particular, it seemed that many micromoths were less mobile than most of the largerbodied taxa. Likewise, new woodlands near remnant woodlands were associated with higher moth richness and abundance, and general recommendations included (1) that new woodlands should focus on planting native species; (2) benefits to moths and wider biodiversity would be increased by management such as thinning to increase structural diversity and accelerate towards later succession; and (3) judicious site selection might increase their contributions to enhancing local biodiversity (Fuentes-Montemayor et al. 2015). Similar recommendations are widespread, for urban woodlands in Scotland (Lintott et al. 2014), again emphasising the needs for tailored local management based on more widespread principles. The spectrum of plants established may have wider conservation implications: species hosting numerous Lepidoptera species may be preferred as foraging sites by insectivorous birds, for example (Piel et al. 2021). A rather different Scottish restoration programme involved the replacement of alien conifers grown on former blanket bog areas, intending to restore the bog and the characteristic moths that depend on it. Plantations of Sitka spruce (Picea sitchensis) and Lodgepole pine (Pinus contorta) established during the 1980s have been progressively removed by felling/harvesting, and a chronosequence survey of moths along a series of restoration ages (years since felling and accompanying ditch modifications) from plantation to unmodified bogs showed the parallel shifts towards open habitat moths and away from forest specialists, so that moth assemblages on restoration sites gradually converged towards bog assemblages (Pravia

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et al. 2020), with the spectrum influenced by traits such as dispersal and habitat breadth. One complication arose from the differences in tree-clearing methods over the 18 years—from chainsawing of young trees in the first few years to the need for larger ground-harvest approaches for large trees later. The forest ‘legacy effect’ of increased drainage (above) was a serious constraint on assemblage changes, because typical bog conditions had not developed within the period examined: although vegetation shifted towards open bog flora, some key species (such as Sphagnum) had not regenerated fully, attributed to the sites still being too dry and effectively slowing or hampering restoration progress. Such effects may be very difficult to detect or predict, but this legacy effect prevented the development of the anticipated typical bog moth fauna (Pravia et al. 2020). Much has been learned from outcomes of the progressive abandonment of agricultural lands in Europe, and the processes by which the areas can again support wider biodiversity, through the alternative strategies of leaving them alone to undertake some natural trajectory of changes (commonly, ‘rewilding’) or management to guide that path more clearly on ecologically degraded land. Merckx (2015) discussed the traditional ‘hands-off’ non-interventionist approach for Lepidoptera on European farmland and recommended that where necessary, accompanying management should be used to provide greater habitat heterogeneity at a variety of scales to foster benefits to larger numbers of species. Maintaining and restoring habitat heterogeneity were considered key to benefitting Lepidoptera on European marginal farmland. A broader perspective of ‘rewilding’ equates it with the wider restoration of species and ecological processes to maintain or increase biodiversity, so management may encompass processes such as reestablishing ‘natural’ burning or grazing regimes, assisted migration and reintroductions of species earlier present and believed to now be missing. ‘Keystone species’ may have particular importance in functional rewilding. Lorimer et al. (2015) noted that under the common aim of reversing human impacts by restoration, whether passively or actively, rewilding embraces ’a range of different goals, contexts, approaches, and tools’. Most emphasis on rewilding in Australia has had a rather different foundation based primarily on the functions provided by small mammals and apex predators, reflecting the absence of large-bodied native herbivores (Sweeney et al. 2019). Measures such as constructing large fenced enclosures to exclude introduced predators such as foxes and feral cats also led to such safeguarded areas constituting valuable and largely unheralded insect habitats. Smaller-scale exercises for insects have received far less attention under this name, but because a high proportion of Australian people live in urban areas, urban ‘rewilding’ of even small areas of gardens and parks has considerable relevance and importance, not least to facilitate natural colonisation or to establish conditions for key released insects. Sweeney et al. distinguished two purposes of species translocations to restored habitats as (1) translocations for the conservation of the species and (2) translocations for the species to perform an ecological role, with the latter being rewilding. In semi-natural grassland in southern England, field-scale habitat restoration clearly influenced the diversity of moths, and this scale was proposed as useful for increasing ecosystem services from moths on nearby farmland (Alison et al. 2017).

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Increased coverage of woody vegetation on restored grassland, as important features of natural calcareous grassland, was also recommended. Enhancement of flora is a widespread central theme in habitat restoration for insects, with practical management benefitting both plants and their associates. Evaluating the success of any attempt, noted in the context of agri-environment schemes by Alison et al. (2017), necessitates comparisons of (1) the treated site and untreated sites of the similar initial condition and (2) benchmark sites as above. Restoration sites may be selected on their position. As examples, they may be sited to increase the effective size of a habitat patch by extending the edges, or reduce adverse edge effects, or provide ‘stepping stones’ to facilitate movements and connectivity between other patches. Considerations such as landscape conductance in relation to fostering immigration and colonisation as ranges change from climate changes may be important (p. 89).

10.3

Captive Rearing and Translocation

Most of the discussion above relates to field-based conservation. However, some form of ‘ex situ’ management may also become important as a source of increased numbers of individuals. Captive rearing of Lepidoptera to provide healthy individuals for release or translocation is a frequent component of butterfly conservation exercises and draws on the long-accumulated experiences of hobbyists. The numerous examples provide many parallels for moth studies. Each rearing and release experience may furnish experiences of hindrances and facilitating steps towards success, or understanding reasons for failure, whether through direct transfer of insects for release elsewhere, or through captive breeding. Each case also emphasises the importance of basic biological knowledge of the species’ requirements throughout its development and a clear focus on the aim/purpose of planning the exercise. The extensive guidelines on translocations and related activities developed for England (DEFRA 2021) parallel needs in Australia and display the variety of purposes and contexts where such approaches may be contemplated. The major categories are (1) population restoration, through reinforcement (increasing population size for greater viability or representation of particular groups or stages) or reintroduction (movement of individuals to a historical site from where it has been lost); (2) conservation introduction (translocations to sites outside the species’ natural range); (3) assisted colonisation (movements to benefit a species’ conservation status, at scales from local to regional); and (4) ecological replacement (movement to reestablish a specific ecological function that has been lost through the extinction of another species—usually involving a closely related taxon presumed to have the same or similar ecological capability). Any such exercise can become intensive and expensive and may extend over considerable periods needed to maintain confined populations over many generations—both to build up numbers for release and to ensure that the proposed receptor site is suitable and secure. It may,

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for example, be necessary to prepare or restore a receptor site to increase its hospitality. The reintroduction of the Netted carpet moth (Eustroma reticulatum, Geometridae) to a historical site in England necessitated the establishment of larval food plants after a period of their earlier extreme scarcity that apparently led directly to the moth’s earlier demise there (Hooson and Haw 2008). Post-release monitoring may also be needed over at least several years to determine the success (or otherwise) of the release. Any moth reintroduction or related activity thus needs careful planning and costing, but sometimes this is thwarted by the urgent need for some form of ‘rescue’ from a site that is to be destroyed at short notice and for which planning time is not available. The policy matters enumerated for Britain (Butterfly Conservation 2010: BC) merit much wider thought elsewhere, not least in the need for a formal proposal to detail the case, conditions and process to replace more casual exercises, and the need for a long-term management plan. Relevant to some cases for Golden sun-moth, BC ‘considers that “rescue” translocation is ‘unacceptable as an excuse for permitting the destruction of sites occupied by rare and threatened species’. They noted also that the long-term culture of captive-bred stock for later release is discouraged, and stock should not normally have been captive for more than two generations, in part to avoid or reduce problems of genetic decline or disease. Sanitation is a key need to prevent the introduction and spread of pathogens such as viruses that are transferred easily through captive stocks and may lead to high mortality in receptor populations. Less frequently heeded, infections by endosymbiotic bacteria can also cause complex effects and ‘exacerbate the challenges faced by conservation managers’ (Hamm et al. 2014), because they have several hard-todetect effects and inadvertent introductions may increase the risk to the receptor population through changes to reproductive behaviour and preferences of the host. Of necessity, captive populations of a rare species may be founded from a single moth or very few individuals, with the likelihood of deleterious inbreeding or other genetic effects arising. The failure of attempts to release captive-bred stock to conserve the Essex emerald moth (p. 65) in England, for example, was attributed in part to the resulting inbreeding depression (Waring 1993). Exposure to parasites or disease is an acknowledged risk in translocations and captive breeding. Especially for field-collected specimens, whether for direct transfer or founding breeding stocks, some form of quarantine and screening for any disease is common (Vaughan-Higgins et al. 2017) as an aspect of biosecurity more widespread for deliberate introductions such as potential biological control agents. Measures proposed for the highly threatened Fisher’s estuarine moth (Gortyna borelii lunata, Noctuidae) in a captive breeding exercise to avoid weakening the sole field population in southern England by removing individuals directly in attempting to found a population at a second site involved the use of a dedicated rearing facility adjacent to a zoo. Quarantine measures involved a disinfectant footbath, dedicated boots and clothing, disposable gloves and the use of dedicated tools. Staff servicing the moths had no contact with other non-native invertebrates at the zoo and attended to the moths early in the day, before servicing the zoo collection in order to reduce the chances of introducing further contaminants. Signage explained the quarantine

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Moths in Australia: Conservation Targets or Passengers?

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barrier (Vaughan-Higgins et al. 2017). Earlier translocations were attempted as part of designing management for this moth and involved transplants of the larval food plant (Peucedanum officinale, Apiaceae) to the new site, where they were protected from grazing by a rabbit-proof fence. A single batch of about 300 Gortyna eggs hatched after introduction, and both plant and moth appeared to thrive (Ringwood et al. 2004), despite fears of potential inbreeding of the moth because of a narrow genetic base. Wolbachia is the bacterium of greatest concern in this context and was found by Hamm et al. in 19 of the 22 threatened Lepidoptera they examined in North America. In particular, cytoplasmic incompatibility may have considerable impacts on small populations—usually those most likely to be targeted for augmentation by releases. At the extreme, such Wolbachia infections may induce a population bottleneck and, should the population be too small to pass through this, it may be lost. A study on the North American Karner blue butterfly (Nice et al. 2009) showed that Wolbachia was widespread across populations in the western half of the butterfly’s range, but had very low incidence (in only 1 of 71 individuals screened) in the eastern half. They warned against using large Western populations as sources for individuals to be translocated to augment small Eastern populations. Nice et al. also noted the particular difficulties with Wolbachia because its impacts may not be detectable until after the introduction of infected individuals. In Australia, and elsewhere, routine screening for Wolbachia (and perhaps also other endosymbionts) would be a wise precaution against increasing chances of risk to any receptor population of a threatened native insect. With exception of the Golden sun-moth (p. 162) moth translocations have only rarely been contemplated seriously in Australia, but this context could increase in the future, together with the need for screening for pathogens. For S. plana, the prospect of ‘salvage’ from sites in the path of development by translocating turf sods containing early stages and embedding them elsewhere has been advanced, and trials in the Australian Capital Territory have been rewarding. Rowell (2019) used both soil/sods and direct transfers of individual moth larvae implanted close to suitable food tussocks to move S. plana from a development site to a designated offset site where the moth was not known to occur previously. Later monitoring inspections, including pupal case counts and sightings of adult moths, implied success, but the longer-term outcome has yet to be confirmed.

10.4

Moths in Australia: Conservation Targets or Passengers?

Many constraints on conserving moths emerge from the previous discussion and collectively emphasise the immense practical difficulties of defining what is to be conserved and how to go about this and also what has indeed been lost or simply remained invisible and undetected. Even if consensus on priority and need occurs,

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the wider means to support and sustain a conservation programme may not be available beyond the enthusiasm of a few concerned advocates, and gaining ‘official’ support from Commonwealth or Regional government agencies remains highly uncertain. Focus on ‘single species’ most closely parallels much other conservation efforts for Australia’s flagship vertebrates or vascular plants, for which wider sympathy is commonly more forthcoming by these providing a tangible target or focus. The reality that public and political interest in moths (and, to even greater extent, most other insects) is likely to increase to the extent that it can become widely persuasive is utopian. Numbers of Australian ‘icon’ or ‘flagship’ moth species are unlikely to proliferate, although apparent declines of familiar large species such as the Emperor gum moths (Opodiphthera eucalypti, O. helena, Saturniidae) formerly not uncommon in many near-urban areas attract occasional concerned comment. Priorities given to the Bogong moth (p. 171) and Golden sun-moth (p. 162) are justified largely through the wider contexts and impacts of their declines. The former exhibits the unusual feature of long-distance mass migrations, when the adult moths formerly aroused much comment when entering lit buildings or sport arenas, but its wider ecological roles as critical sustenance for an endangered marsupial are emphasised in conservation management for the pygmy possum, together with wider threats to the alpine environment. Synemon plana has become a major ambassador for threatened native grasslands in the south-east, together with two threatened reptiles restricted to those grasslands that also harbour numerous scarce and threatened plant species. It has become the centre of the far-reaching debate about the further loss of grasslands to development, in the context that perhaps 99% of the former grassland area has been alienated. In this case, interest has flowed to other restricted Castniidae. The two reptiles have drawn wide concerns because of declines and loss of habitat and many recent surveys have failed to record them over much of their former ranges. The Grassland earless dragon (Tympanocryptis pinguicolla, Agamidae) now occurs in parts of the Australian Capital Territory and adjacent New South Wales, but may be extinct in its former Victorian range to the west of Melbourne and is ‘Endangered’. The Striped legless lizard (Delma impar, Pygopodidae) is also threatened and very patchily distributed, and the focus of a specific national conservation plan and captive breeding exercises. S. plana may benefit from conservation plans for these species, simply by sharing the sites that must be protected, but tailored management of those areas to consider the moth more specifically may augment its security. Such wider notoriety is not available for most other Australian moths. Despite their biological idiosyncrasies, restricted distributions or as isolated endemic taxonomic oddities of global significance, the low number of designated ‘listed’ species is unlikely to either increase markedly or, if increased, to be heeded constructively and undergo the transition from listing to practical conservation. For most scarce moths, wider ecological roles can be stated only very imprecisely, and the perception of many people that ‘moths are pests’ is still very real. Nevertheless, the increasing number of records and photographs of moths on iNaturalist and other sites is testament to continuing interests and a forum for promoting further awareness. And, from the greater legacy of conservation support for butterflies, many of the

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broad ecological and practical fundamentals for moth conservation are well-defined both for species and assemblages. That many moths cannot be identified or named reliably to species other than by specialists and that even many of the named species are both difficult to recognise and their biology at present largely unstudied are impediments to specifically incorporating them further into targeted conservation activities. Likewise, moth species richness is difficult to characterise fully in most major habitats, and the constituent species of special conservation significance are rarely definable. Reported species numbers can be impressively high—but those numbers also convey intangibility and feelings of ‘helplessness’ in evaluating needs and priorities convincingly, even when threats are apparent. From that viewpoint, a broader perspective might be more rewarding, even if a direct focus on moths gives way to wider considerations of habitat and resource conservation, whether based on Australia’s ‘bioregions’ (Taylor et al. 2018) or more directly on vegetation associations or sites to ensure the widest variety and the extent of natural and remnant environments are protected and, where necessary, rehabilitated. Likewise, the wider importance of pollinating insects for crop and ornamental plants has been emphasised mainly through bees and flies and recommendations to construct ‘bee highways’ and otherwise promote connectivity and nectar supply by increasing the supply and variety of native flora. Those measures, together with reduced pesticide uses, can help to protect numerous other insects, including moths. Moths may indeed benefit from the more widespread measures to conserve insect pollinators. The ‘bioregions approach’ (based on the Interim Biogeographic Regionalisation for Australia system, commonly known as ‘IBRA’) recognises the variety of Australia’s environments and that many of them are still substantially underexplored for insect life, with this reflected in the very low numbers of insect (and other invertebrate) species signalled as of conservation interest. In parallel, a number of recognised biodiversity hotspots have no or few invertebrates recognised and, conversely, some IBRA regions with more listed species are not accorded ‘hotspot’ or another priority status. Many are remote, and detailed surveys are necessarily expensive and logistically difficult, as discussed earlier. Taylor et al. (2018) considered that seeking insect ‘flagships’ or ‘icons’ (with high scientific importance) for each of the 89 bioregions could help to draw attention to the wealth of life forms and their needs for survival, by acting as ‘umbrellas’—but little progress has occurred with this endeavour. Writing generally on insects, Taylor et al. noted that most listed species have been from the mesic parts of the continent, mostly from coastal or nearcoastal areas of eastern Australia and Western Australia with very few listed from arid areas. As an example of a wider lack of faunistic knowledge for key ecological regions, the Great Victoria Desert bioregion has an area of about 418,750 km2, bridging Western Australia and South Australia. A short ‘BioBlitz’ survey over a limited area of the Desert in South Australia in 2017 yielded 86 species of Lepidoptera, 13 of them butterflies, but only 27 moth species had been identified by the time of the published report (Bush Blitz 2019). Such ‘snapshots’ are an invaluable contribution to documenting a local fauna, but simply ‘whet the appetite’ for fuller investigations, which at present seem unlikely to occur on any systematic basis.

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Most of the 36 bioregions with no listed invertebrates were semiarid or arid. The bias from most entomological expertise and interest residing in coastal urban areas in the southern and eastern parts of Australia and the remoteness of much of the country produces a considerable mismatch between ideals and the current reality of coverage, but provides much evidence for conservation need throughout the region—and, in practice, concentrates conservation effort in the most conspicuously disturbed regions that are more accessible. Many possible candidate groups could be nominated for advancing insect conservation in Australia, and ‘larger moths’ are perhaps amongst the most suitable, second only to butterflies. That advance may build on a substantial existing array of studies, institutional reference collections, photographic records and citizen science interest and support, and amenability to light-trap sampling by hobbyists, the last drawing from both aesthetic ‘collector’ interest and scientific inquiry. They are thus far more ‘tractable’ than most other large insect groups, and, despite the incomplete systematic study, most specimens encountered are recognisable to family, many to genus level—and some to species level by use of easily available illustrated guides and texts, with provision to gain further advice from posting illustrations. Despite the undoubted popularity of Coleoptera as another ecologically varied and taxonomically rich group, interest and capability to use beetles (with some likely exceptions such as the Jewel beetles [Buprestidae] long popular with hobbyists) in any parallel way lags far behind the advantages apparent for moths, for which a ‘critical mass’ of interest and expertise has demonstrated significant and continuing progress in understanding the fauna. Focus on both the ‘most natural’ ecosystems (to clarify the real extent of moth diversity in relation to key habitat characteristics) and ‘most disturbed’ vegetated areas (to assess the real impacts of changes) in the main bioregions and making the data available for consultation and reference would do much towards establishing the level of real conservation need. It is clearly premature to advocate any detailed formal mapping for recording distributions of Australia’s moths—but also salutary to reflect on the immense benefit of such schemes, as shown so effectively for the United Kingdom and elsewhere. The fine-scale distribution recording (based on 10 × 10 km squares over the whole region, and notwithstanding its limitations) developed there is logistically impracticable in Australia, and most evaluations of distribution are less formal and far less complete. Evaluations of the distribution parameters used in formal conservation status determinations, namely ‘area of occupancy’ (AOO) and ‘extent of occurrence’ (EOO) are thus usually uncertain and may need careful consideration (IUCN 2022). The latter is based on ‘known, inferred or projected sites of present occurrences’, with ‘inferred’ based on habitat characteristics and knowledge such as dispersal capability of the species involved and other biological factors that collectively lead to a high likelihood of occurrence at other sites. AOO, a recognition of possible species range through associating the entire number of sites from where it has been recorded, may include vast areas of the unsuitable country. Nevertheless, as discussed for Ward’s atlas moth (p. 167) by Braby and Nielsen (2011), aspects of geographical range and associated habitat fragmentation (as within IUCN’s ‘Category B’ for ranking threat status) are the most

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Fig. 10.2 Distribution map of Ward’s atlas moth, Attacus wardi, showing known populations (solid circles) and former record (open circle), the extent of occurrence and the geographical range in northwestern Australia (Braby and Nielsen 2011)

suitable criteria for insect evaluations because no information is needed on population sizes and dynamics. The very limited information on Attacus wardi as summarised in Fig. 10.2 displays an estimated geographical range of 600 km, and EOO of 64,000 km2. Within this, the very limited extent of monsoon forest and that much of it is fragmented extensively and unsuitable core breeding habitat for the moth renders the AOO likely to be 70% over the previous two decades and that declines had occurred across many plant groups. Highly managed sites generally had lower rates of decline—but many gaps in coverage and awareness persisted, and the true status of numerous other plants had not been established. Most of the distribution records leading to the above accounting were from only four states: South Australia, Victoria, New South Wales and Western Australia, and greater coverage from other areas is needed. Many threats to plants overlap with those to moths, but with the additional (but rare) complication that conservation management of a rare plant might entail protection from herbivory by suppression of its consumers!

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Nevertheless, almost all of the ‘Threatened ecological communities’ listed under EPBC have a botanical component in their definition and delimitation, so formal notice of many plant associations in need of conservation is recorded. Parallel surveys of moths across those communities (with provision for repeated surveys as monitoring) would be highly desirable, and assembling the already existing local incidence records constitutes a valuable component of the needed fuller documentation and helps to hone management needs for wider collective benefits. The reality that plant richness, structural variety and the naturalness of undisturbed vegetation associations are a key determinant and influence Lepidoptera well-being and that heterogeneity within anthropogenic environments should focus largely on vegetational diversity has been emphasised repeatedly as a fundamental need in moth conservation. Relatively general findings and inferences from surveys across different habitats, some noted in earlier chapters, include (1) loss of plant variety coincides with the loss of moth variety; (2) in highly altered environments many ecologically specialised moths decline or are lost, with this often linked to loss of specific larval food plants; (3) moth assemblages in those environments largely comprise polyphagous or otherwise generalist species, perhaps sufficiently abundant to give an impression of sustained richness and abundance; and (4) preservation or restoration of natural or even small vegetation patches in a transformed landscape that is still sufficiently connected play vital roles in moth conservation. These principles apply widely across many anthropogenic environments and endorse the measures noted earlier that are needed to conserve moths (and others) in response to impacts of agricultural intensification, urbanisation and forestry activities as the major transformative pressures in Australia, in conjunction with effectively protected and adequately representative natural areas. At present, moths are generally amongst the unsung passengers in such conservation programmes, which may (1) target other threatened taxa or (2) have a much wider intent for conserving biodiversity and emphasise the need for ‘habitat’ to sustain many life forms. They may also benefit, but have rarely been investigated specifically in Australia. As one important context, many roadsides in Australia are recognised for having botanical significance—many short roadside lengths, indeed, are signed to indicate their importance and that roadside maintenance should be sympathetic and heed that worth. The considerable area of roadside vegetation is both residential habitat and a potential commuter corridor for many insects now scarce in adjacent built or agricultural landscapes (New et al. 2021) and their extent is surprising. For example, including features such as intersections and pull-offs, the area of managed roadside habitat in Finland (then about 140,000 ha) was estimated at seven times the area of remaining semi-natural grassland (Saarinen et al. 2005). In Australia, many rural roads traverse wholly transformed agricultural landscapes and essentially harbour the only remaining fragments of some regional vegetation associations. Despite their considerable variety, roadside strips are commonly narrow and compromised through fuel or chemical run-off, dumping, herbicides and insecticides, mowing and slashing, accidental or deliberate burning and the chance of destruction for additional road widening. Optimal management is usually unclear—mowing, for

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example, can have very different impacts according to seasonality, frequency and mowing height. In Europe, Saarinen et al. (2005) showed that some diurnal moth species have adapted to regular mowing of roadsides, but other meadowland species depended on the presence of taller vegetation for shelter, so benefited from lack of mowing. As noted by Valtonen et al. (2006), mowing regimes are one of the easiest roadside management components to be modified, with moves to reduce mowing often welcomed as a financial saving to the local authority. The timing of annual mowing may be critical, because mowing destroys the early stages of moths and affects nectar supplies for adults. Comparisons of butterflies and diurnal moths along transects in roadside areas that were mown in mid-summer, late summer or only partially mown without consideration of season suggested that no single time could completely avoid some losses of early stages, but that ‘late summer’ may be the better seasonal option (Valtonen et al. 2006). The richness of both butterflies and diurnal moths declined after mid-summer mowing, and either delaying mowing or promoting mosaic mowing may benefit both groups. The same principle emerges for meadow management (Merckx et al. 2012). In parallel, the conservation significance of field margins has become a major focus of agri-environment schemes, whereby such margins can be preserved from cultivation as refuge habitats for moths and others; their importance has been enhanced with large-scale agricultural conversion. Wider field margins (more than 6 m) can locally increase the numbers of larger moths (Merckx et al. 2012). Increased vegetation cover within about 250 m can lead to increased moth richness and abundance in agricultural environments (Fuentes-Montemayor et al. 2011). Hedgerow trees along margins increase habitat variety. And, as for roadsides, the extent of hedgerows may be unexpectedly large; in the United Kingdom, the 477,000 km of hedgerows has been described as ‘the most widespread semi-natural habitat in heavily human-dominated landscapes across England’ (Facey et al. 2014). Roadsides and field margins are noted here simply to exemplify the extent, variety and significance of such commonly overlooked insect habitats. In addition to the more obviously extensive and better-documented forests or open grasslands, such initially unpromising lands may be critical for some moth species—but that significance in Australia is still to be recognised by detailed study. One acknowledged parallel is for the Bulloak Jewel butterfly (Hypochrysops piceatus, Lycaenidae) (Sands 2018), for which the major known population is confined to a short and vulnerable roadside strip in Queensland, where its specific food plant and mutualistic ant species co-occur. It may not be unique, but continuing vigilance is needed to prevent losses of such small but critical areas from road widening, vegetation clearance and other pressures that may affect one or more of these interacting taxa. Wherever they occur, the protection of remnants of roadside and other natural vegetation in urban and agricultural areas can have wide conservation benefits. But, again, the full distributional details of the moth species present in any such remnant and their ecological needs, vulnerabilities and dependencies are usually unknown. The future of many Australian moths depends on wider measures to conserve native biodiversity. Those measures perhaps especially extend from the experiences gained

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from butterflies through their greater conservation prominence and emphasise that even very small patches of vegetation—including many areas (such as those noted above) likely to be disregarded as ‘insignificant’ by many non-entomologist managers—may indeed have critical importance as the only sanctuaries available for local moth species or assemblages in highly transformed landscapes. A series of major themes for increased understanding of conservation assessments and needs of Australia’s butterflies (initiated by Sands and New 2002) extends easily to moths, with the ‘gaps’ leading to these recommendations still far greater for moths. The seven recommendations were the (1) need for additional surveys; (2) need for additional biological information; (3) need for habitat security; (4) need for habitat restoration; (5) need for threat evaluation and management; (6) need for effective planning and execution; and (7) need to recognise purposes and roles of listing species, and subsequent actions. Enlisting and sustaining agency and public support to promote, integrate and interpret these measures are a formidable and uncertain endeavour. Much of the future of any insect conservation in Australia devolves on fostering the shared interests and enthusiasms that link the few ‘professional scientists’ with the concerned citizenry. The variety of scales implicit in the above discussion also emphasises that moth and other insect conservation progress depends heavily on the interests and actions of individual people as well as ‘higher level’ dictates and that insect declines can be mitigated by relatively simple actions that can be pursued without the delays common in seeking approval from authorities. Thus, the eight ‘simple actions’ to save insects from decline proposed by Kawahara et al. (2021) are open for adoption and participation by any concerned individuals. They fall into two categories: (1) creating insect-friendly habitats and (2) increasing awareness and appreciation of insects. The first category included five actions: converting lawns into diverse natural habitats by replacing monocultures with more diverse vegetation, growing native plants, reducing pesticide and herbicide usage, limiting the use of exterior lighting, lessening soap and other contaminant run-off from washing vehicles and building exteriors. The remainder, in category 2, were countering negative perceptions of insects, becoming an educator and advocate for insect conservation, and becoming involved in local politics and supporting science to promote insect-friendly policies. Four major foci for policy development in insect conservation that need support from all interest levels exemplify the scales of concern as (1) nations, states, provinces and cities; (2) working lands (farms, ranches, forests); (3) natural areas, including parks, roadsides and other remnants; and (4) gardens, homes and other private property (Forister et al. 2019). Developing an appreciation of Australia’s unique moth fauna is one of the more tangible themes through which the conservation of wider invertebrate diversity, and the variety of Australia’s natural habitats and vegetation systems, may be communicated. As elsewhere in the world, the parallels with butterfly conservation practices provide invaluable lessons for emulation and development—and that background experience and information give moths many advantages over most other insects. A global synopsis of conservation evidence for Lepidoptera (Bladon et al. 2022) displays well the predominance of butterflies in such manipulations—but also the enormous range of case histories and interventions through which ideas and useful

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outcomes have flowed and which contribute to practical conservation. That body of example and information provides abundant scope for further development and rebalancing endeavour to give greater priority to the more abundant sections of the order—not least in Australia where interest and awareness of needs for the rich and remarkable moth fauna are indeed increasing. The future of Australia’s moth fauna cannot depend on a foundation of knowledge of all the taxa present, or full details of the distribution, vulnerability and ecological requirements even of those species already signalled as of concern. Conservation must thus proceed from a highly incomplete knowledge base, as more broadly endorsed by Forister et al. (2019) in urging that action is imperative and that enough is known to make intelligent conservation decisions for insects. The dual foci on moths as ‘targets’, through which strategically selected priority taxa can be studied in detail and conservation management based progressively on sound ecological knowledge, and ‘passengers’ present but not noted specifically in conservation programmes for other taxa or key vegetation types or sites, are both valid and important components of future conservation. The first has greater appeal to many authorities in providing a tangible focus that can be monitored and publicised widely and for which management can become adaptive as knowledge accumulates. The second reflects the central importance of ‘habitat’ safety that may facilitate studies of moth diversity on sites that have been rendered ‘safe’ and further surveys there may support and extend the recognised importance of those areas—in some cases revealing the presence of unusual or undescribed species or unusual associations. Both help to safeguard the unheralded (and in some cases unknown) resident biodiversity that in many cases could not be sustained elsewhere. Most of the 22,000 or so acknowledged taxa of Australia’s moths will remain in the shadowland of wider conservation programmes—and an imperative concern is to ensure that they (and their numerous co-occurring invertebrates, many of them of equivalent systematic and evolutionary significance as locally endemic) do not simply perish in oblivion and join the unknown extinctions that can never be properly recorded in Earth’s history.

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Index

A Agri-environment schemes (AES), 78 Abantiades, 160, 177 Acacia, 101, 103, 107, 113 Acacia kempeana, 110 Acacia ligulata, 110 Acacia mangium, 168 Acacia nilotica, 101 Acalyphes philorites, 151 Acentropinae, 129 Actias luna, 101 Adelidae, 127 Aenetus blackburni, 151 Aenetus virescens, 146 Aenigmatinea glatzella, 5 Agamidae, 208 Agathiphaga queenslandensis, 40 Agathiphagidae, 41, 123, 124 Agavaceae, 26 Agonopterix alstroemeriana, 100, 192 Agricultural intensification, 64, 66 Agrius convolvuli, 9 Agrostis, 73 Agrotis exclamationis, 114 Agrotis infusa, 13, 88, 111, 171–173 Alcis angulifera, 58 Alpine case moth, 144 Alpine grass grub, 144 Amelora acontistica, 144, 150 Amitermes, 166 Amitermes laurensis, 166 Amitermes scopulus, 166 Amitermes vitiosus, 166 Anagraecum sesquipedale, 22 Antbed parrot moth, 126, 150, 165

Anthelidae, 123, 141, 151, 190 Ants, 28 Aoraia, 42, 92 Apiaceae, 100, 207 Aquatic moths, 29, 129 Araucaria, 41 Archiearinae, 169 Arctia menetriesii, 7 Arctiidae, 92, 104 Arctiinae, 2, 30, 44, 54, 55, 75, 88, 92, 96, 100, 104, 190 Aristotelia serrata, 146 Artificial light, 46 Artificial lighting at night (ALAN), 66, 111 Asaphodes, 41 Asaphodes frivola, 41 Asteraceae, 133 Atherton Tablelands, 76 Athetis pallustris, 14, 65 Athrotaxis cupressoides, 169 Atlantic Forest, 96 Attacus wardi, 167, 211 Attractants, 46 Australian bollworm, 21 Australian Moths Online, 124 Autumn gum moth, 111, 140, 145

B Bacillus thuringiensis kurstaki, 88 Banksia montana, 212 Barberry Carpet moth, 128 Barcode Blitz, 8 Barcode Index Numbers, 10 Bardi grubs, 111

© The Author(s), under exclusive license to Springer Nature Switzerland AG 2023 T. R. New, The Other Lepidoptera: Moth Conservation in Australia, https://doi.org/10.1007/978-3-031-32103-0

221

222 Barrens buck moth, 101 Bat–moth relationships, 4 Batrachedra, 201 Belted Beauty moth, 128 Bent-wing Swift moth, 160 Berberis vulgaris, 128 Bessa remota, 42 BIOCLIM, 90 Biodiversity Action Plan (BAP), 15, 155 Bioregions, 130, 209 Blackburn’s sphinx, 40, 105 Black Mountain Reserve, 124, 180 Bogbean buckmoth, 157 Bog bush cricket, 3 Bogong moth, 88, 108, 111, 132, 151, 171–173, 194, 208 Bombycidae, 13 Bombyx mori, 13 Boronia, 26 Breynia oblongifolia, 27 Broad-leaved tea tree, 166 Brown-tail moth, 102 Buglife, 3 Bulloak Jewel butterfly, 214 Buprestidae, 110, 210 Burnet moths, 65, 94 Burramys parvus, 13, 151, 171 Butterfly Conservation, 52, 157, 181

C Cabbage white butterfly, 2 Cacatua tenuirostris, 163 Cactoblastis cactorum, 106 Callosamia promethea, 101 Calyptorhynchus funereus, 146 Calyptra, 28 Capital breeders, 15 Carboniferous period, 4 Carronia multisepalea, 170 Carthaea saturnioides, 123 Carthaeidae, 123 Caryophyllaceae, 26 Castniidae, 6, 12, 47, 130, 150, 152, 154, 159, 161 Caterpillar fungus, 13, 109 Cecropia moth, 101 Cerambycidae, 110 Chalcidoidea, 5 Chevron looper, 150 Chiasmia assimilis, 101 Chiasmia clathrata, 66 Chiasmia inconspicua, 101 Chilean needle grass, 105, 163 Chinese caterpillar fungus, 109

Index Chrysiridia rhipheus, 42 Chrysolarentia decisaria, 150 Chrysoteuchia culmella, 72 Cicadas, 27 Cinnabar moth, 106 Citheronia regalis, 101 Citizen science, 47, 100, 181, 185, 192 Clothes moths, 12, 27 Cochylis atricapitana, 107 Coenophila subrosea, 99, 128 Coloradia pandora, 97 Common barberry, 128 Compsilura, 102 Compsilura concinnata, 101 Conium maculatum, 100 Connectivity, 74 Convolvulus hawk, 9 Corridors, 74 Cosmopterigidae, 29 Cossidae, 110, 111, 145 Cotton webspinner, 21 Crambidae, 4, 5, 7, 21, 26, 29, 45, 92, 124 Cretaceous period, 4 Croton habrophyllus, 168 Cryptic species, 8, 9 Cryptic sun-moth, 160 Cumberland Plain Woodland, 202 Cushion plant moth, 94 Cyclotornidae, 28

D Dactylopius opuntiae, 27 Danaus plexippus, 172 Dark bordered beauty moth, 43 Dasybela achroa, 144, 150 Delma impar, 208 Depressariidae, 100, 192 Diamondback moth, 87 Dilleniaceae, 133 Dirce, 151 Dirce aesiodora, 24, 151, 169 Dirce oriplancta, 151 Ditrysia, 2, 3 DNA barcoding, 8–10, 21, 47 Dryandra moth, 123 Dusky leaf-nosed bat, 21

E Eacles imperialis, 101 Ecological gradients, 29 Ecological traps, 104, 113 Edge effects, 74 Elachistidae, 127, 177

Index Elaeis guineensis, 100 Elaeocarpaceae, 146 Elytrigia juncea, 41 Emperor gum moths, 208 Emperor moth, 13 Endoxyla cinereus, 145 Endoxyla leucomochla, 110 Enigma moth, 5 Enteucha acetosae, 3 Entomophaga, 102 Environment Protection and Biodiversity Conservation Act (EPBC), 140, 150, 154 Eois, 9 Epacridaceae, 94, 129 Epicephala, 27 Epione vespertaria, 43 Epipyropidae, 27 Erebidae, 2, 5–7, 11, 21, 28–30, 54, 55, 58, 88, 92, 96, 100, 101, 104, 106, 107, 150, 170–171, 190, 195 Essex emerald moth, 65, 206 Eublemma albifascia, 28 Eucalyptus, 103, 107, 145, 160 Eucalyptus globulus, 139 Eucalyptus grandis, 146 Eucalyptus marginata, 140 Eucalyptus saligna, 105 Eucalyptus urograndis, 104 Eucalyptus urophylla, 105 Eungella National Park, 7 Euphorbiaceae, 42, 168 Eupithecia, 24, 28 Eupithecia ogilviata, 149 Eupitheciini, 28 Euplagia quadripunctaria, 2 Euproctis chrysorrhoea, 102 Euproserpinus euterpe, 11 Euproserpinus phaeton, 12 Eupterotidae, 44 Eustroma reticulatum, 206 Extinction, 39, 54, 65 Exyra semicrocea, 11

F Fabaceae, 133 Feeding guilds, 35 Fisher’s estuarine moth, 206 Flagship species, 151 Flightlessness, 92 Forester moths, 151

223 Forest tent caterpillar, 74 Fragmentation, 70, 80 Frosted phoenix, 42 Fulgoridae, 27

G Gelechiidae, 6, 92, 127 Geometridae, 5, 6, 9, 11, 24, 26, 28, 30, 40, 43–45, 47, 48, 54, 58, 65, 69, 75, 76, 92, 94, 100, 111, 114, 124, 126, 128, 130, 132, 138, 140, 141, 143, 145, 150, 151, 169, 178, 181, 192, 206 Ghost moths, 3 Giant wood moths, 145 Gippsland Lakes, 183 Glyphipterygidae, 129 Golden-shouldered parrot, 166 Golden sun-moth, 12, 104, 105, 150, 154, 159, 162, 179, 189, 194, 197, 201, 208 Gossypium hirsutum, 107 Graceful sun-moth, 160–162 Gracillariidae, 13, 14 Grammia complicata, 88, 195 Granny’s cloak moth, 21 Graphania erebia, 26 Grasshoppers, 92 Grassland earless dragon, 208 Great Otway National Park, 178, 183 Great Victoria Desert, 209 Green tree ant, 28 Grizzly bears, 13 Gypsy moth, 88, 101, 107, 144

H Hadena, 26 Halo effect, 75 Hawk moths, 9, 15, 155 Heart and Dart moth, 114 Hecatesia exultans, 151 Hecatesia thyridion, 47 Hednota, 124 Hedylidae, 2 Helicoverpa, 112 Helicoverpa punctigera, 21 Heliothis armigera, 112 Heliothis punctigera, 112 Heliozelidae, 26, 81, 127, 142 Hemileuca iroquois, 157 Hemileuca lucina, 101 Hemileuca maia menyanthevora, 157

224 Hemiptera, 212 Hepialidae, 3, 13, 42, 45, 92, 110, 144, 146, 151, 154, 160, 177 Hesperiidae, 2 Hestiochora rufiventris, 151 Hestiochora tricolor, 151 Hipposideros ater, 22 Hippotion scrofa, 133 Homoptera, 27 Hooded parrot, 166 Horehound, 107 Horehound plume moth, 107 Hyalophora cecropia, 101 Hybridisation, 11 Hydrilla, 130 Hydrilla verticillata, 130 Hydrillodes morosa, 58 Hypochrysops piceatus, 214 Hyposmocoma, 28, 29 Hyposmocoma molluscivora, 28

I Ichneumonoidea, 5 Imbrasia belina, 13 Imperial moth, 101 iNaturalist, 185, 191, 208 Income breeders, 15 Indicators, 3, 24, 90, 126, 139, 189 Intensive forest management (IFM), 77 Interim Biogeographic Regionalisation for Australia (IBRA), 209 Inventory, 49 Island tiger moth, 88, 195 IUCN Red Data Book criteria, 152

J Japanese larch, 72 Jersey tiger moth, 2 Jewel beetles, 210

K Kaka, 146 Karner blue butterfly, 207 Kauri moth, 40 Kern primrose sphinx moth, 11 Keystone species, 22 Koala, 125 Kona giant looper, 40

Index L Laetilia coccidivora, 27 Land-use intensity (LUI), 72 Lantana, 105 Lantana camara, 105 Lappet moths, 123 Larentiinae, 9, 132 Larix kaempferi, 72 Lasiocampidae, 6, 74 Latticed heath, 66 Leaf mines, 14 LED lights, 112 Levuana iridescens, 42 Light-traps, 45, 47, 81, 111, 130 Lodgepole pine, 203 Lomandra hermaphrodita, 161 Lomandra maritima, 161 Lomera caespitosae, 144 Long-billed corellas, 163 Lophocereus schottii, 26 Lophocorona melanora, 124 Lophocoronidae, 124 Luperina nickerlii leechi, 41, 47 Lycaenidae, 28, 214 Lycia zonaria britannica, 128 Lymantria, 108 Lymantria dispar, 101, 107, 144 Lymantriinae, 101, 102, 107

M Macroglossinae, 15, 76 Macrolepidoptera, 3 Macromoths, 3 Makomako, 146 Malacosoma disstria, 74 Malaise traps, 46 Mallee moths, 126 Manduca blackburni, 40, 105 Marrubium vulgare, 107 Marsh moth, 14, 65 Mary Cairncross Park, 159 Megacraspedus, 6 Megafires, 97, 142 Melaleuca viridiflora, 166 Melanism, 90 Menetries’ tiger moth, 7 Menispermaceae, 170 Menyanthaceae, 158 Menyanthes trifoliata, 158 Metapopulation, 68

Index Metrioptera brachyptera, 3 Microlepidoptera, 3, 6, 8, 14, 73, 123, 157, 177 Micropterigidae, 2, 16, 123, 127 Middle Triassic, 4 Miniopterus orianae bassanii, 21 Mnesampela privata, 111, 140, 145 Monarch butterfly, 172 Monophagy, 23 Monterey pine, 107, 141 Moon moth, 101 Morphospecies, 50 Morwell National Park, 182 Mount Kinabalu National Park, 75 Mountain pygmy possum, 13, 151, 171 Mt Jirisan National Park, 51, 58 Mutualisms, 21, 26 Myrtaceae, 126, 145, 166, 177 Mythimna turca, 185

N Nassella neesiana, 105 Nassella trichotoma, 163 Nasutitermes exitiosus, 166 National Action Plan, 192 National Moth Night, 181 National Moth Recording Scheme (NMRS), 52 National Reserve System, 198 Nemotyla oribates, 94 Neonicotinoids, 88 Nepticulidae, 3, 127, 177 Nestor meridionalis, 146 Netted carpet moth, 206 New Forest burnet, 109 Nhill Sun-Moth Reserve, 199 Nicotiana glauca, 106 Noctuidae, 6, 11, 13, 14, 21, 26, 41, 45, 47, 53, 54, 58, 65, 69, 72, 88, 92, 99, 106, 107, 112, 114, 128, 132, 133, 151, 171–173 Noctuoidea, 133 Nothocestrum, 105 Nothofagus, 124, 142 Notodontidae, 6 Notoreas, 11, 48 Notoreas perornata, 48, 123 Nursery pollinators, 26 Nymphalidae, 11, 172

O Oak leaf-miner, 105 Oecophoridae, 28, 45, 92, 94, 126, 140, 142, 150, 165, 182

225 Oecophylla longinoda, 28 Oecophylla smaragdina, 28 Oenochroma barcodificata, 178 Oil palm, 100 Olethreutinae, 177 Oligophagy, 23 Omphalea, 42 Omphalea triandra, 42 Oncopera alpina, 144 Ophiocordyceps sinensis, 13, 110 Opodiphthera eucalypti, 208 Opodiphthera helena, 208 Opostegidae, 127 Opuntia, 106 Orchid, 22 Orgyia thyellina, 108 Ornithoptera richmondia, 104 Orocrambus fugitivellus, 92 Oryza sativa, 107 Overcollecting, 109 Oxycanus, 154

P Painted apple moth, 108 Pale sun-moth, 163 Pandani moth, 129 Pandora moth, 97 Papilionoidea, 2 Parasitoids, 67, 101, 145 Parategeticula, 26 Pareulype berberata, 128 Pectinivalva, 177 Pencil pine, 169 Pencil pine moth, 169 Persectania, 132 Peucedanum officinale, 207 Phaeton sphinx, 12 Phalaenoides glycine, 133 Phascolarctos cinereus, 125 Pheromone traps, 46 Phragmites, 158 Phyllanthaceae, 27 Phyllodes imperialis, 159 Phyllodes imperialis smithersi, 11, 150, 170–171 Phyllonorycter messaniella, 81, 105 Picea sitchensis, 203 Pieridae, 2, 88 Pieris rapae, 2 Pimelea cf urvilleana, 48 Pinus contorta, 203 Pinus radiata, 106, 107, 140, 145

226 Pitcher plant moth, 11 Platyptilia isodactyla, 107 Plutella xylostella, 87 Plutellidae, 87, 92, 129 Poa, 144 Poa costiniana, 91 Poaceae, 107, 124 Podocarpus National Park, 75 Poison hemlock moth, 100 Pollination syndromes, 25 Pollinators, 5, 13, 21, 88 Polyphagy, 23 Porina, 42 Prickly acacia, 101 Prickly pear, 106 Pringleophaga, 22 Pringleophaga marioni, 22 Proditrix nielseni, 24, 129 Prodoxidae, 26 Promethea moth, 101 Proteaceae, 212 Psephotus, 28 Psephotus chrysopterygius, 166 Psephotus dissimilis, 166 Pseudococcidae, 212 Pseudococcus markharveyi, 212 Psychidae, 92, 144 Pterolocera, 151 Pterophoridae, 107 Puriri moths, 146 Pygmy blue-tongue lizard, 163 Pygmy leaf-mining moths, 177 Pygopodidae, 208 Pyralidae, 4, 5, 47, 129 Pyraloidea, 4, 7, 75

Q Qualifiers, 194 Quercus, 105, 113

R Radiata pine, 140 Ragwort, 106 Ragwort plume moth, 107 Ragwort stem and crown boring moth, 107 Refuges, 80 Regal moth, 101 Remuremu looper, 41 Reserva Biologica San Francisco, 10 Resource-based habitat, 68 Richea pandanifolia, 129 Richmond birdwing butterfly, 104 Roadsides, 213

Index Rosy marsh moth, 99, 128 Rothamsted Insect Survey, 39, 54

S Salicaceae, 43 Salix repens, 43 Sand couch grass, 41 Sandhill rustic moth, 41 Sarracenia, 11 Saturniidae, 6, 13, 15, 17, 39, 44, 45, 97, 101, 104, 167, 208 Scat moths, 125 Scotorythia megaphylla, 40 Senecio jacobaea, 106 Senita cactus, 26 Senita moths, 26 Serrated tussock, 163 Sesiidae, 46 Silene, 26 Silk moths, 15 Singletons, 50 Sitka spruce, 203 Sloane’s Urania, 42 Small ermine moths, 11 Small whistling moth, 151 Smerinthinae, 15, 76 Snails, 28 Snapshots, 179 Snow grass, 91 Solanaceae, 105 Sorghum, 107 Sorrell pygmy moth, 3 Southern beech, 124 Southern bent-wing bat, 21 Southern pink underwing moth, 11, 150, 159, 170–171 Southern whistling moth, 47 Species replacement, 43 Speiredonia spectans, 21 Sphagnum, 204 Sphingidae, 9, 11, 15, 17, 22, 26, 29, 39, 40, 44, 75, 104, 131, 133, 155, 177 Spodoptera frugiperda, 107 Stepping stones, 74 Striped legless lizard, 208 Stylidiaceae, 94 Succession, 71 Sun-moths, 6, 130, 154, 159 Sus scrofa, 172 Swift moths, 3 Sword grass brown butterfly, 11 Synemon gratiosa, 160 Synemon plana, 12, 150, 154, 162, 179, 189, 208

Index Synemon selene, 163, 199 Synemon theresa, 160

T Tachinidae, 101 Tasmanian blue gum, 139 Tasmanian Saltmarsh looper, 150 Taxodiaceae, 169 Tegeticula, 26 Teia anartoides, 108 Termite mounds, 28, 126, 166 Tettigoniidae, 3 Thetidia smaragdaria maritima, 65 Thitarodes, 13, 110 Threat status, 64 Threatened ecological communities, 213 Threatened Plant Index of Australia, 212 Thymelaeaceae, 48 Tiger moths, 30, 54, 96, 190 Tiliqua adelaidensis, 163 Tineidae, 22, 27, 127 Tisiphone abeona, 11 Titanomis sisyrota, 42 Tornatellides, 28 Tortricidae, 5, 45, 47, 142, 177 Transect walk, 47 Tree tobacco, 106 Trisyntopa, 28 Trisyntopa neossophila, 126, 166 Trisyntopa scatophaga, 126, 150, 165 Tritrophic systems, 67 Tunbridge looper, 150 Tussock grassland moths, 45 Tympanocryptis pinguicolla, 208 Tyria jacobaeae, 106

U Upiga virescens, 26 Urania sloanus, 42

227 Uraniidae, 42 Urbanisation, 66, 80, 112, 139 Ursus arctos horribilis, 13

V Valley of the Butterflies, 2 Verbenaceae, 105 Vine moth, 133 Voltinism, 93

W Ward’s atlas moth, 152, 167, 210 Wet Tropics, 143 Wheeleria spilodactylus, 107 Wing reduction, 91 Witchetty grub, 110

X Xanthopan morganii, 22 Xanthorhoini, 138

Y Yellow-tailed black cockatoos, 146 Yponomeuta, 11 Yponomeutidae, 11 Yucca, 26

Z Zea mays, 107 Zelotypia stacyi, 151, 160 Zygaena anthyllidis, 94 Zygaena carniolica, 65 Zygaena exulans, 94 Zygaena viciae, 65, 109, 128 Zygaenidae, 42, 46, 47, 65, 72, 94, 109, 151