This page intentionally left blank Insect Species Conservation Insects are the most diverse and abundant animals that share our world, and conservation initiatives are increasingly needed and being implemented globally, to safeguard the wealth of individual species. This book provides sufficient background information, illustrated by examples from many parts of the world, to enable more confident and efficient progress towards the conservation of these ecologically indispensable animals. Writing for graduate students, academic researchers and professionals, Tim New describes the major ingredients of insect species management and conservation, and how these may be integrated into effective practical management and recovery plans. tim new is Professor of Zoology at La Trobe University, Australia. He has broad interests in insect ecology, conservation and systematics, and has published extensively in these fields. He is recognised as one of the leading advocates for insect conservation. He is currently editor-in-chief of the Journal of Insect Conservation. ECOLOGY, BIODIVERSITY AND CONSERVATION Series editors Michael Usher University of Stirling, and formerly Scottish Natural Heritage Denis Saunders Formerly CSIRO Division of Sustainable Ecosystems, Canberra Robert Peet University of North Carolina, Chapel Hill Andrew Dobson Princeton University Editorial Board Paul Adam University of New South Wales, Australia H. J. B. Birks University of Bergen, Norway Lena Gustafsson Swedish University of Agricultural Science Jeff McNeely International Union for the Conservation of Nature R. T. Paine University of Washington David Richardson University of Cape Town Jeremy Wilson Royal Society for the Protection of Birds The world’s biological diversity faces unprecedented threats. The urgent challenge facing the concerned biologist is to understand ecological processes well enough to maintain their functioning in the face of the pressures resulting from human population growth. Those concerned with the conservation of biodiversity and with restoration also need to be acquainted with the political, social, historical, economic and legal frameworks within which ecological and conservation practice must be developed. The new Ecology, Biodiversity, and Conservation series will present balanced, comprehensive, up-to-date, and critical reviews of selected topics within the sciences of ecology and conservation biology, both botanical and zoological, and both ‘pure’ and ‘applied’. It is aimed at advanced final-year undergraduates, graduate students, researchers, and university teach- ers, as well as ecologists and conservationists in industry, government and the voluntary sectors. The series encompasses a wide range of approaches and scales (spatial, temporal, and taxonomic), including quantitative, theoretical, population, community, ecosystem, landscape, historical, experimental, behavioural and evolutionary studies. The empha- sis is on science related to the real world of plants and animals rather than on purely theoretical abstractions and mathematical models. Books in this series will, wherever possible, consider issues from a broad perspective. Some books will challenge existing paradigms and present new ecological concepts, empirical or theoretical models, and testable hypotheses. Other books will explore new approaches and present syntheses on topics of ecological importance. The Ecology of Phytoplankton C. S. Reynolds Invertebrate Conservation and Agricultural Ecosystems T. R. New Risks and Decisions for Conservation and Environmental Management Mark Burgman Nonequilibrium Ecology Klaus Rohde Ecology of Populations Esa Ranta, Veijo Kaitala and Per Lundberg Ecology and Control of Introduced Plants Judith H. Myers, Dawn Bazely Systematic Conservation Planning Chris Margules, Sahotra Sarkar Assessing the Conservation Value of Fresh Waters Phil Boon, Cathy Pringle Bird Conservation and Agriculture Jeremy D. Wilson, Andrew D. Evans, Philip V. Grice Large Scale Landscape Experiments David B. Lindenmayer Insect Species Conservation T. R. New Insect Species Conservation T. R. NEW Department of Zoology, La Trobe University, Australia CAMBRIDGE UNIVERSITY PRESS Cambridge, New York, Melbourne, Madrid, Cape Town, Singapore, São Paulo Cambridge University Press The Edinburgh Building, Cambridge CB2 8RU, UK Published in the United States of America by Cambridge University Press, New York www.cambridge.org Information on this title: www.cambridge.org/9780521510776 © T. R. New 2009 This publication is in copyright. Subject to statutory exception and to the provision of relevant collective licensing agreements, no reproduction of any part may take place without the written permission of Cambridge University Press. First published in print format 2009 ISBN-13 978-0-511-54022-6 eBook (EBL) ISBN-13 978-0-521-51077-6 hardback ISBN-13 978-0-521-73276-5 paperback Cambridge University Press has no responsibility for the persistence or accuracy of urls for external or third-party internet websites referred to in this publication, and does not guarantee that any content on such websites is, or will remain, accurate or appropriate. Contents Preface page xi Acknowledgments xv 1 Needs and priorities for insect species conservation1 Introduction: extinctions and conservation need1 Planning priorities among species4 Criteria for assessing priority7 Overcoming lack of population data: going beyond numbers 19 Rarity and vulnerability 28 Species and related conservation units 35 Inferring and defining threat 39 Further focus and need 43 Community modules and insect species conservation 47 Summary 51 2 Plans for insect species conservation 53 Introduction: basic principles and scope 53 Scales and focus 58 Management options 63 Assessing progress 69 Summary 79 3 Habitat, population and dispersal issues 81 Introduction: concepts of habitat 81 Habitat models 85 Species, resources and population structure in management 90 Landscape features 98 Summary 100 viii · Contents 4 Current and future needs in planning habitat and resource supply 103 Introduction: space and time in insect conservation management 103 Dispersal and connectivity 104 Future needs: climate change 107 Summary 120 5 Beyond habitat: other threats to insects, and their management 121 Introduction: key threats to insects 121 Alien species 122 Pesticides 127 Overcollecting 129 Summary 142 6 Adaptive management options: habitat re-creation 145 Introduction: improving habitats for insects 145 Restoration 146 Some management approaches 152 Natural and anthropogenic habitats 160 Habitat re-creation 161 Summary 164 7 Re-introductions and ex situ conservation 167 Introduction: the need for ex situ conservation 167 Re-introduction 167 Captive rearing 175 Releases 183 Re-introduction sites 187 Summary 189 8 Roles of monitoring in conservation management 191 Introduction: the need for monitoring 191 Criteria for monitoring 194 Approaches to monitoring 196 Summary 204 9 Insect species as ambassadors for conservation 205 Introduction: extending the conservation message 205 Contents · ix Temperate region insects 205 Tropical insects 209 Summary 211 10 Insect management plans for the future 213 Introduction: the audience and purpose for insect management plans 213 Constructing an insect recovery plan 219 Alternatives to a formal management plan? 223 Consultation and acceptance 225 After recovery? 229 Summary 230 References 233 Index 253 Preface This short book is about conserving insects, the most diverse and abun- dant animals that share our world. In particular, it is about the common focus of conserving individual species of insects. This so-called ‘fine filter’ (or ‘fine grain’) level of conservation parallels much conservation effort for better-understood groups of animals such as mammals and birds, for which species-focused conservation exercises are commonplace. The need for insect conservation can appear puzzling, and how to undertake it can seem daunting to the many conservation practitioners unfamiliar with insects but to whom vertebrates or vascular plants are familiar – and, thus, that they can treat with greater confidence because of being within their range of practical expertise. We are thus dealing with insects as specific targets or individual foci for conservation. My main aim is to provide sufficient background information, illustrated by examples of insect species needs and conservation programmes from many parts of the world, to enable more confident and efficient progress for conserva- tion of these ecologically indispensable animals. I hope to demonstrate and clarify to potential managers what the major ingredients of insect species management for conservation may be, and how those needs and ingredients may be integrated into effective and practical management or recovery plans. The examples demonstrate the great variety of needs of ecologically specialised insects, the small scales over which they may operate, and how both assessment of conservation status and design of species conservation necessarily differs from that for many of the more popular and more widely understood organisms. The need for such an appraisal has been stimulated largely by my experiences in Australia, where most people involved ‘officially’ in man- aging insects for conservation, such as by belonging to State or Territory conservation or related agencies, are (in common with many people in similar positions elsewhere in the world) not primarily entomologists, but versed in the management or ecology of vertebrates or other organisms. xii ·