ch00-prelims.qxd 10/30/03 2:50 PM Page i GENETICS, EVOLUTION AND BIOLOGICAL CONTROL ch00-prelims.qxd 10/30/03 2:50 PM Page ii ch00-prelims.qxd 10/30/03 2:50 PM Page iii Genetics, Evolution and Biological Control Edited by L.E. Ehler University of California, Davis, USA R. Sforza USDA, Montpellier, France and T. Mateille IRD, Montpellier, France CABI Publishing ch00-prelims.qxd 10/30/03 2:50 PM Page iv CABI Publishing is a division of CAB International CABI Publishing CABI Publishing CAB International 875 Massachusetts Avenue Wallingford 7th Floor Oxon OX10 8DE Cambridge,MA 02139 UK USA Tel:+44 (0)1491 832111 Tel:+1 617 395 4056 Fax:+44 (0)1491 833508 Fax:+1 617 354 6875 E-mail:[email protected] E-mail:[email protected] Web site:www.cabi-publishing.org ©CAB International 2004.All rights reserved.No part of this publication may be reproduced in any form or by any means, electronically,mechanically,by photocopying,recording or otherwise,without the prior permission of the copyright owners. A catalogue record for this book is available from the British Library,London,UK. Library of Congress Cataloging-in-Publication Data Genetics,evolution,and biological control/edited by L.E.Ehler,R.Sforza, and T.Mateille. p.cm Papers from an International Organization for Biological Control symposium held in Montpellier,France,2 002. Includes bibliographical references and index. ISBN 0-85199-735-X (alk.paper) 1. Pests--Biological control--Congresses.2.Biological pest control agents--Congresses. I.Ehler,Lester E.II.Sforza,R.(Rene) III.Mateille,T.(Thierry) IV.International Organization for Biological Control.V.Title. SB975.G.46 2004 632´.96--dc21 2003009939 ISBN 0 85199 735 X Typeset by MRM Graphics Ltd,Winslow,Bucks Printed and bound in the UK by Cromwell Press,Trowbridge ch00-prelims.qxd 10/30/03 2:50 PM Page v Contents Contributors xi Preface xiii 1. Genetic Structure of Natural Plant and Pathogen Populations 1 J.J.Burdon and P.H.Thrall Introduction 1 Natural variation in host–pathogen associations 2 Disease resistance in plant populations in their native range 3 Variation in space:host–pathogen interactions as metapopulation associations 5 Host and pathogen variation in new environments 7 What is the resistance structure of invasive host populations? 7 How important is continuing natural selection for the maintenance of resistance in introduced populations? 9 How rapidly will resistance respond to the re-application of pathogen selective pressures? 11 Improving biological control strategies 12 How do host and pathogen life-history features and the environment interact to determine the genetic basis of resistance? 12 What are the selective consequences of rapid versus slower declines in population size? 13 Conclusions 14 Acknowledgement 15 References 15 v ch00-prelims.qxd 10/30/03 2:50 PM Page vi vi Contents 2. Measuring Genetic Variation in Natural Enemies Used for Biological Control:Why and How? 19 E.Wajnberg Introduction 19 Why measure intrapopulation genetic variation in natural enemies? 20 Methods for measuring intrapopulation genetic variation 22 Parent–offspring regression 24 Sib analysis 24 Family analysis 24 Breeding selection 25 Intrapopulation genetic variation in insect parasitoids 26 What characters should be studied? 29 Conclusion 31 Acknowledgements 31 References 31 3. Molecular Systematics,Chalcidoidea and Biological Control 39 J.Heraty Introduction 39 Genes of interest 42 Genetic divergence 44 Identification 49 Phylogenetics and their applications 52 Relationships of Chalcidoidea 52 Relationships within Chalcidoidea 53 Eucharitidae:competing morphological and molecular trees 54 Encarsia:unchallenged trees and the interpretation of change 56 Phylogeography and invasive agents 59 Cospeciation 59 Conclusion 63 Acknowledgements 65 References 65 4. Genetic Markers in Rust Fungi and their Application to 73 Weed Biocontrol K.J.Evans and D.R.Gomez Introduction 73 Rust fungi as biocontrol agents of weeds 74 Genetic markers in rust fungi 75 Pathotyping 76 Selecting molecular markers for population-genetic studies 76 Relative utility of some common DNA markers 77 Emerging technologies 78 Application of molecular markers in weed biocontrol 78 ch00-prelims.qxd 10/30/03 2:50 PM Page vii Contents vii Investigating relationships between weed diversity and pathogen variation 78 The skeleton rust story 79 The blackberry rust story 80 Identifying the released pathogen with certainty 83 The musk thistle rust story 83 Identifying and monitoring the fate of the released pathogen strain with certainty 84 Population genetics of rust fungi in relation to strain selection 85 Locating centres of diversity and evolutionary new associations 88 Conclusions 90 Acknowledgements 91 References 91 5. Tracing the Origin of Pests and Natural Enemies:Genetic and Statistical Approaches 97 G.K.Roderick Introduction 97 Problems and approaches 98 Patterns of spread 98 Invasion genetics 98 Types of genetic markers 103 Genealogies 104 Analysis of frequencies 106 Bioinformatics 107 Other methods 107 Discussion 107 Conclusions 108 Acknowledgements 109 References 109 6. Tracing the Origin of Cryptic Insect Pests and Vectors,and their Natural Enemies 113 J.K.Brown Introduction 113 Application of phylogeographical analysis of insect pests and vectors, and natural enemies 115 Genetic markers 116 Studies in which molecular markers have been employed for taxonomic identification and tracking of cryptic Hemipterans 118 Invasion of the B biotype Bemisia tabaciin the Americas and evidence for a species complex 118 Phylogeographical matching between B.tabaci mitochondria COI haplotypes and natural enemies from the same geographical origin 121 ch00-prelims.qxd 10/30/03 2:50 PM Page viii viii Contents First demonstration that an invasive B.tabaciis associated with the spread of severe cassava mosaic disease in East Africa 123 Upsurge of Myndus crudus,the vector of the phytoplasma inducing lethal yellowing disease of palm,and rapid disease spread following Hurricane Mitch 126 Divergence of aphids on non-cultivated hosts:determining haplotypes and plant hosts using a mitochondrial marker 129 Tracking Mediterranean fruit fly introductions in California using composite genotypes 130 Conclusions 131 Acknowledgements 131 References 132 7. Predicting Evolutionary Change in Invasive,Exotic Plants and its Consequences for Plant–Herbivore Interactions 137 H.Müller-Schärer and T.Steinger Introduction 137 Framework and scope of our study 139 Selection pressure in invaded habitats and expected selection on plant traits 140 Properties of invaded habitats 140 General traits associated with plant invaders 141 Traits related to competitors and antagonists 141 Caveats 143 Genetic variation in invasive plants 145 Reduced genetic variation in invasive plant populations? 145 Caveat:low correlation between molecular- and quantitative-genetic variation 147 Increased genetic variance through hybridization 148 Observed evolutionary response 149 Outlook 153 Emerging research topics 154 Acknowledgements 155 References 155 8. Experimental Evolution in Host–Parasitoid Interactions 163 A.R.Kraaijeveld Introduction 163 Field ‘experiments’ 164 Experimental evolution in host–parasitoid systems 165 House flies 165 Drosophila 166 Discussion 173 Lack of genetic variation for resistance 173 Resistance is costly 174 ch00-prelims.qxd 10/30/03 2:50 PM Page ix Contents ix Genotype ×genotype interactions 174 Parasitoids can evolve 174 Selection pressures fluctuate in space and time 175 Concluding thoughts 176 References 177 9. Interactions Between Natural Enemies and Transgenic Insecticidal Crops 183 J.J.Obrycki,J.R.Ruberson and J.E.Losey Introduction 183 Bacillus thuringiensisversus predators and parasitoids 185 Insect predators 186 Parasitoids 188 Field surveys of natural enemies in transgenic insecticidal fields 190 Predatory arthropods 190 Parasitoids 193 Insect pathogens 195 Risks and benefits of transgenic insecticidal crops for natural enemies 197 Conclusions 198 References 199 10. The GMO Guidelines Project:Development of International Scientific Environmental Biosafety Testing Guidelines for Transgenic Plants 207 A.Hilbeck and the Steering Committee of the GMO Guidelines Project Introduction 207 Needs assessment 210 Plant characterization 211 Non-target and biodiversity effects 212 Gene flow and its consequences 216 Resistance management 216 Conclusion 217 References 217 11. Genetic Manipulation of Natural Enemies:Can We Improve Biological Control by Manipulating the Parasitoid and/or the Plant? 219 G.M.Poppy and W.Powell Introduction 219 Genetic manipulation 220 Genetic manipulation of parasitoids 221 Parasitoid manipulation via the plant 226 Conclusions 228 References 229 ch00-prelims.qxd 10/30/03 2:50 PM Page x x Contents 12. Sex-ratio Distorters and Other Selfish Genetic Elements: Implications for Biological Control 235 R.Stouthamer Introduction 235 Overview of sex-ratio distorters and their potential application 236 Female-biasing sex-ratio distorters 236 Male-biasing sex-ratio distorters 243 Application of PSR factors in biocontrol 245 Other heritable bacteria of importance to biological control 245 Cytoplasmic imcompatibility-inducing Wolbachia 245 Detection of sex-ratio distorters and CI-Wolbachiain natural enemies 247 Discussion 248 References 248 Index 253