Biological Control 1. Adult banana skipper, Erionota thrax (L.M. Nakahara). 2. Young E. thrax larva commencing to roll a banana leaf (R.F.L. Mau). 3. Rolled banana leaf sheltering a larger larva (D.PA Sands). 4. Young banana plant stripped by E. thrax larvae (L.M. Nakahara). 5. Adult spiraling whitefly, Aleurodicus dlspersus (PAC. Ooi). 6. Wax spiral deposited during A. dispersus oviposition (PAC. Ooi). Biological Control Pacific Prospects - Supplement 1 D.F. Waterhouse K.R. Norris Australian Centre for International Agricultural Research Canberra 1989 The Australian Centre for International Agricultural Research (ACIAR) was established in June 1982 by an Act of the Australian Parliament. Its mandate is to help identify agricultural problems in developing countries and to commission collaborative research between Australian and developing country researchers in fields where Australia has a special research competence. Where trade names are used this constitutes neither endorsement of nor discrimination against any product by the Centre. ACIAR MONOGRAPH SERIFS This peer-reviewed series contains the results of original research supported by ACIAR, or deemed relevant to ACIAR's research objectives. The series is distributed internationally, with an emphasis on the Third World. © Australian Centre for International Agricultural Research G.P.O. Box 1571, Canberra, A.c.T. 2601. Waterhouse, D.F., and Norris, K.R. 1989. Biological control: Pacific prospects­ Supplement 1. ACIAR Monograph No. 12, vii + 125 p. ISBN 0949511 986 Typeset and laid out by Arawang Information Bureau Pty Ltd, Canberra. Printed by Inprint Limited, Brisbane. Contents Foreword vii l. Introduction 1 2. Biological control and its implementation 4 3. Aleurodicus dispersus spiraling whitefly 12 4. Frankliniella occidentalis western flower thrips 24 5. Thrips tabaci onion thrips 36 6. Hypothenemus hampei coffee berry borer 56 7. Hel/ula spp. cabbage centre grubs 76 8. Erionota thrax banana skipper 88 9. References 101 10. Index of scientific names of insects 119 v Foreword When Biological Control: Pacific Prospects by D.F. Waterhouse and K.R. Norris was published in 1987 under ACIAR's South Pacific Program I expressed the view that it would prove to be a valuable source of data, facilitating the selection and pursuit of target pests and weeds for biological control. In this it has already been highly successful and there has been a substantial increase in the number of biological control projects undertaken, one of which (the white peach scale on passion fruit in Western Samoa) has already resulted in effective controL At each of the three regional plant protection meetings held since the decision at the TonganlACIARlGTZ Workshop on Biological Control in 1985, to publish Pacific Prospects, ACIAR has been requested to arrange for the preparation of dossiers on additional pests. It is agreed that this is, indeed, a highly relevant and important activity for ACIAR to support, and furthermore it has become clear that the information is often required with some urgency. It has, therefore, been decided to publish dossiers in groups as they are written, a policy vindicated by the fact that two of the projects very recently initiated in the Pacific deal with newly-invading species which are treated here. These are the banana skipper Erionota tbrax, which has recently spread rapidly in Papua New Guinea, and the spiraling whitefly Aleurodicus dtspersus, which is living up to its specific name and dispersing widely and rapidly in the Pacific region. ACIAR is very grateful for the wealth of information proVided by many individuals in the Pacific, who have supplied unpublished observations and indicated great enthusiasm and support for the project; also to Dr Gabrielle Persley and Mr Paul Ferrar of its Crop Sciences program for helping to steer this important undertaking further along the road to success. j.R. McWilliam Director Australian Centre for International Agricultural Research, Canberra 1989 vii 1 Introduction The six pest dossiers in this publication follow closely the format adopted in Biological Control: Pacific Prospects. Each was chosen following recommendations of the Plant Protection meetings in Apia in 1986 and Noumea in 1987. One of the pests, the western flower thrips Frankliniella occidentalis is not yet established in the oceanic south west Pacific, although it is perceived to be a significant threat if its frequent interception continues in both Guam and New Zealand in produce from California. Biological control programs have already been initiated against two others (the banana skipper and the spiraling whitefly), which have come to prominence since Pacific Prospects was completed. The distribution and importance in the Pacific of the six pests is shown in Table 1.1, using the conventions adopted previously. No attempt has been made to present an exhaustive survey of all the literature on a particular pest, espedally in relation to chemical control, in which recommendations often rapidly become outdated. On the other hand every effort has been made to cover the literature relevant to biological control, including the biological and ecological information upon which successful biological control often depends. Once again, the presentation of the material is heavily biased towards the south west Pacific and discussion is focussed on the relevance of the information to traditional and other agriculturists in this region. At the same time, the dossiers have very much Wider relevance, since all of the pests are also important outside the region. It would not have been possible to assemble the wide range of relevant information in this book without the ready assistance of many colleagues throughout the Padfic and elsewhere, who have given generously of their time and knowledge. This will become clear to the reader from the number of unpublished observations quoted. The use of technical terms has been kept to a minimum and the widely used term 'parasite' has been employed again in this publication instead of the more technically correct 'parasitoid', since no confusion is thereby introduced amongst the main target readership. Some 250 spedes of insects are referred to in the chapters and the author, order and family of each is provided in the index of scientific names of insects. There have been many changes to the names used in the literature quoted in the chapters. These changes have been incorporated as far as possible, although not all modem experts agree on what the correct terminology should be. In general, that of the Commonwealth Institute of Entomology and the British Museum of Natural History has been adopted where there is dispute. Since nomendatural changes, particularly of genera, frequently make it difficult to use indexes to earlier literature, the practice has been adopted of listing superseded names used by earlier authors at the first citation of a species in a chapter by enclosing them, preceded by an equals sign in brackets following the name in current use, for example 'Nepbaspis oculatus ( => N. amnicolor)'. Our action is not intended to imply that the two taxa are precise synonyms of one another, since frequently they are not, and the change has been made for other reasons. At the front of each chapter there are two maps, one shOWing a stylised world distribution of the pest and the other the regional distribution and importance assigned to it in the Pacific. The lines on the map do not imply that all islands, archipelagos or land masses 1 N c:l 0' S cl' Teble 1.1 The distribution and importance of six insect pests of concern to the south west Pacific. !!!. KEY: one of the country's worst pests .. important locally +++ widespread pest, causing important damage P present, but unimportant ~ .... less widespread, but of great importance Blank not recorded ~ '"'Cl ~ Chapter Scientific Common Cook Is Fiji French Guam Hawaii Kiribati New Niue Papua New American Western Solomon Tokelau Tonga Tuvalu Vanuatu :::;; name name Polynesia Caledonia Guinea Samoa Samoa Is C'r '"'Cl Hemiptera Aleyrodidae 3 Aleurodicus spirating .. .. .. P .. + + + + -0~ dispersus whits fly Thysanoptera ~ Thripidae 4 Frankliniella western ? + I occidentalis flower (/) thrips c: S Thrips onion .. .. .. .. + + + .. -0 thrips -0 Coleoptera Scolytidae 6 Hypothenemus coffee hampei berry .. ++ .. + ..... I ..... Lepidoptera Pyralidae 7 He/lula spp. cabbage .. P P +.. + P ++ P centre +++ ++ grubs Hesperiidae 8 Erionota thrax banana P P skipper +++ 1 Introduction 3 encircled are necessarily infested and the positions of the lines often follow political boundaries. As additional information becomes available, there will certainly be a need to adjust the extent of some of the areas included. The precis at the front of each chapter is designed to serve not as a balanced summary, but as an aide-memoire to some of the key matters relating to prospects for biological control. We are happy to acknowledge the facilities generously provided by the Division of Entomology, CSIRO and the valuable assistance of many of its staff, in particular Dr M. Carver and Mr E.D. Edwards. Thanks are also due to many others with special knowledge of Pacific entomology, including Professor w.e. Mitchell, University of Hawaii and Dr P.A. Maddison, DSIR, Auckland. We are grateful also for the advice on taxonomic problems provided by the CAB International Institute of Entomology (Dr RG. Booth, Dr M.L. Cox, Mr G.J. DuHeaume, Dr ].D. Holloway, Dr RB. Madgi, Dr A. Polaszek, Dr G. Stonedahl, Ms A.K. Walker, Dr G.M. Watson, Dr LM. White, Dr M.R Wilson) and the British Museum (Natural History) (Mr S.]. Brooks, Mr M. Shaffer, Mr B.e. Townsend, Mr N.P. Wyatt). Biological control 2 and its implementation Many of the topics in this chapter are dealt with in greater detail in Biological Control: Pacific Prospects (Waterhouse and Norris 1987), which is drawn upon extensively. The concept of biological control Biological control may be defined as the action of natural enemies (parasites, predators, phytophagous organisms and pathogens) in maintaining an organism at a lower average abundance than it would attain in their absence.