Insect Pests in Tropical Forestry, 2nd Edition We dedicate this book to our families, Trish, Richard, and Gev, and Ang, Cate, Nick, Richard, and Toby, for their patience and support during the writing of both editions of this book. Insect Pests in Tropical Forestry, 2nd Edition Dr F. Ross Wylie Department of Agriculture, Fisheries and Forestry, Queensland Government, Australia Dr Martin R. Speight Zoology Department, University of Oxford, and St Anne’s College, Oxford, UK CABI is a trading name of CAB International CABI CABI Nosworthy Way 875 Massachusetts Avenue Wallingford 7th Floor Oxfordshire 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] Website: www.cabi.org © F.R. Wylie and M.R. Speight 2012. 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 Wylie, F.R. Insect pests in tropical forestry / F. Ross Wylie, Martin R. Speight. -- 2nd ed. p. cm. Includes bibliographical references and index. ISBN 978-1-84593-635-8 (pbk : alk. paper) -- ISBN 978-1-84593-635-5 (hardback : alk. paper) 1. Forest insects--Tropics. 2. Forest insects--Control--Tropics. I. Speight, Martin R. II. Title. SB764.T73W95 2012 595.71734--dc23 2011042626 ISBN-13: 978 1 84593 636 5 (Hbk) 978 1 84593 635 8 (Pbk) Commissioning editor: Rachel Cutts Editorial assistant: Alexandra Lainsbury Production editor: Simon Hill Typeset by SPi, Pondicherry, India. Printed and bound in the UK by CPI Group (UK) Ltd, Croydon, CR0 4YY. Contents Preface vii 1 Tropical Forests 1 2 Tropical Forests and Insect Biodiversity 22 3 Abiotic and Biotic Effects 49 4 Insect–Host Tree Interactions 75 5 Tropical Forest Pests: Ecology, Biology and Impact 91 6 Management Systems I: Planning Stage 153 7 Management Systems II: Nursery Stage 186 8 Management Systems III: Plantation Stage 204 9 Management Systems IV: Forest Health Surveillance, Invasive Species and Quarantine 240 10 Integrated Pest Management (IPM) 275 Bibliography 297 Index 357 v This page intentionally left blank Preface Since the publication of the first edition of this book in 2001, there have been several sig- nificant developments in forestry and forest entomology in the tropics that warranted inclusion in a second edition. One is the emergence of new pest species associated either with the expansion of plantation forestry into new regions or marginal areas, or a gradual adaptation by indigenous species to exotic hosts or the rapid spread of new invasives. The South American carpenterworm, Chilecomadia valdiviana, in Chile, and the South African goat moth, Coryphodema tristis, are examples of emerging indigenous pests associated with the establishment and expansion of exotic Eucalyptus spp. plantations in these coun- tries. The blue gum chalcid, Leptocybe invasa, and the erythrina gall wasp, Quadrastichus erythrinae, are recent examples of the rapid worldwide spread of an invasive insect, similar to that which occurred for the leucaena psyllid, Heteropsylla cubana, in the 1980s and 1990s. The biology, ecology and impact of these, and many additional pest species, are discussed in an expanded Chapter 5. Another development has been the growing awareness of the ‘true’ global impact of forest invasive species as losses have been better quantified. Damage worldwide has been estimated at several billion US dollars per year, even without taking into account the loss of non-market value, which may well exceed that figure. This has prompted a range of international responses, including the formation of networks and surveillance programmes to provide early warning of incursions of forest invasives and the development of interna- tional standards for phytosanitary measures, such as that for wood packaging material, as discussed in Chapter 9. The global increase in self-help schemes such as plant clinics and field schools is also discussed. A range of new technologies has enhanced the accuracy and efficiency of forest health surveys over the past decade. These include the use of geographic information system–global positioning system interface tools and handheld computers to assist navigation and data collection in the field, and the application of digital, remotely sensed imagery to detect and classify damaged forest canopies. There have also been signifi- cant advances in the use of semiochemicals, including pheromones, for the detection and monitoring of forest pests and for controlling pest populations by means of mass trapping, lure and kill, lure and infect and mating disruption. One of the fundamental principles underlying this book is that the prevention of prob- lems is far better than attempts at cures. The book is not in any way designed to be a manual of pest management. Instead, it presents concepts and examples of tropical forest vii viii Preface insects, their ecology, impact and control approaches where appropriate, and we hope that individual readers will make the connection between the generalities in the book and their own situation, socio-economic position and appropriate technologies. Some situations or examples have been revisited several times in different parts of the book, and some amount of repetition has been inevitable, and indeed vital. So, for example, the eucalyptus longi- corn beetle, Phoracantha semipunctata, is discussed in chapters on ecology, host-plant relationships, plant resistance, biological control and integrated pest management, while the mahogany shoot borer, Hypsipyla spp., crops up almost as often. As can be seen from Chapter 1, we have been fairly broad in our definition of ‘tropi- cal’. Clearly, insects do not take any notice of atlases and an example from the subtropics (however defined) may have just as much relevance to equatorial regions. In some cases, it has been necessary to use even temperate examples where none are available from more tropical regions. We have kept this to a minimum and though there may well have been several examples of concepts or techniques that are well established from temperate situa- tions, we have strived to provide a tropical one instead. Our aim has also been to provide a complete global perspective on tropical forest pest ecology and management; hence the rather general nature of the contents. We have attempted to paint as broad a picture as pos- sible, using examples from as many tropical countries as we have experienced personally or are well represented in the literature. Clearly, there will be omissions. Not all countries and all major pests have been treated exhaustively. We hope that interested readers, whether from the Pacific, Australasia, South and South-east Asia, Africa and both Central and South America, will find something of relevance to them personally and will also discover expe- riences outside their regions to be of significance to their own situations. Finally, we had to decide which forest types to focus on and have been sparing in our mention of native or natural forests. Essentially, this is a book about plantation forestry, either grown intensively on a large scale or at a local, small-scale level as part of village or agroforestry systems. The layout of this second edition follows that of the first, though the content has been substantially rewritten to reflect 10 years of research and development, as well as the emer- gence of new pest species. Chapter 1 presents an overview, from a somewhat entomological perspective, of tropical forestry in its many guises. Chapters 2, 3 and 4 then discuss the ‘pure’ biology and ecology of tropical insects and their co-evolved relationships with the trees and forests in which they live. We discuss both abiotic (climatic) and biotic (food and enemies) factors, and together we hope that some of the ways in which ‘neutral’ forest insects become pests and, in turn, are subsequently reduced to low levels will become clear. The later, more ‘applied’ chapters base their management tactics on this earlier, pure science. It must not be forgotten that one person’s pest may be another’s rarity. Insect bio- diversity in tropical forests is an extremely popular and important area for both discussion and research and we have touched on this aspect of insects in forests in Chapter 2. Chapter 5 is necessarily the largest chapter in the book, looking in detail at a selection of major pest species from all over the tropical world. As mentioned above, these examples are not in any way exhaustive – that would be a quite impossible task – but, instead, pro- vide case histories to illustrate a whole range of insect types, from defoliators and sap feed- ers, to shoot, bark and wood borers. Chapters 6, 7, 8 and 9 then discuss the theory and practice of insect pest management, starting at the fundamental planning stage, before any seeds hit the soil. If basic concepts and problems are not tackled and handled correctly at this first stage, then, in many cases, no amount of effort or expenditure in the future will fix problems to come. We then consider, in turn, nursery management and stand management in Chapters 7 and 8. The reader will notice a certain amount of ‘pigeonholing’ here. For example, the vital topics of biological and chemical control have relevance to all stages of tree growth and forest management, but we have chosen to put them in Chapter 8 since, in the majority of cases, this is where the techniques and concepts described find most practi- cal use. Chapter 9 covers the topics of forest health surveillance, quarantine and forest Preface ix invasive species, topics which again have significance at all stages of forestry but for con- venience are presented after nursery and forest management.