UNIVERSITY OF HAWAl'1 LIBRARY MASS PRODUCTION OF ANAGYRUS ANANATIS GAHAN (HYMENOPTERA: ENCYRTIDAE) FOR THE AUGMENTATIVE BIOLOGICAL CONTROL OF PINK PINEAPPLE MEALYBUG DYSMICOCCUS BREVIPES (COCKERELL) (HOMOPTERA: PSEUDOCOCCIDAE) A DISSERTATION SUBMITTED TO THE GRADUATE DIVISION OF THE UNIVERSITY OF HAWAI'I IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY IN ENTOMOLOGY DECEMBER 2002 BY RAJU RAJ PANDEY DISSERTATION COMMITTEE: Marshall W. Johnson, Chairperson Russell H. Messing Neil J. Reimer John S. Hu Andrew D. Taylor © Copyright 2002 by Raju R. Pandey iii Dedication Dedicated to the farmers ofNepal who encouraged me to conduct pest management studies in their farms during my early stage ofentomology career. iv ACKNOWLEDGEMENTS I like to express special thanks to my major Advisor Marshall Johnson for his continuous guidance, encouragement, support and patience throughout this work. Thanks to my committee members Drs Russell Messing, John Hu, Neil Reimer and Andy Taylor for their interest, suggestions and support to conduct the research work. Research was supported by USDA- CSRESS grant. It would have been impossible for me to pursue graduate study at the University ofHawaii without the Scholarship from East West Center. Dr Ron Mau provided opportunity to work as a teaching assistant. Dr Cerruti Hooks was a great help in many ways. Mike Nomura helped maintain mealybug and the parasitoid culture so that I could spend more time in conducting research. He also helped in field works. Drs Brent Sipes and Koon Hui Wang allowed to conduct some ofmy field research in their field. Gerath Nagai helped to maintain the field study sites. All three pineapple companies (Dole, Del Monte and Maui pine and Land companies) provided me unrestricted access to their fields to collect insects required for my study. Drs Gary Carr and CliffMorden (Botany) helped to identify weeds. I am grateful to all the faculty, staff and graduate students ofthe department for their help and friendship. Special thanks to Mildred Uegawachi and Lynn Hata for keeping track ofall the paper works. Moral support ofmy family members back in Nepal and the Nepalese community in Honolulu was important. Love, patience and understanding ofmy wife Sancheeta, son Suveg and daughter Subigya made it possible to undertake this journey. v ABSTRACT Pink pineapple mealybug (PPM), Dysmicoccus brevipes (Cockerell) (Homoptera: Pseudococcidae), transmits Pineapple Mealybug Wilt Associated Virus (PMWaV) (Closteroviridae: Closterovirus) in Hawaii. In the presence ofPMWaV, feeding by PPM induces Mealybug Wilt ofPineapple, which can completely devastate a pineapple planting ifPPM is not managed. Studies were conducted to develop an augmentative biological control program for PPM management using the encrytid endoparasitoid Anagyrus ananatis Gahan. Use ofvermiculite in PPM rearing protocols effectively removed PPM generated honeydew that commonly entrapped mealybugs and interfered with collection ofPPM individuals from squash. Infestation ofKobocha squash with mature adult PPM produced more than 2200 mature adult PPM (2 0.6 mg) per kg squash in about 8 weeks. The size ofparasitized PPM significantly affected A. ananatis body size, which partially determined the parasitoid's reproductive ability. PPM weighing 2 0.6 mg produced normal sized A. ananatis. The lower developmental threshold (To) for A. ananatis was l2.65°C. Total heat accumulation required for development from egg to adult was 265 and 275 Degree Days (DD) for males and females, respectively. Eggs began hatching after accumulating 22 DD and larval development was completed after 88-110 DD. Anagyrus ananatis pupae can be stored at 10.1 °C (below the To) for one week, ifpreconditioned at l4.8°C (above the To) for one week, without significant effects on their survival and reproductive abilities. vi Big headed ant (BHA), Pheidole megacephala F. (Hymenoptera: Fonnicidae), effectively reduced A. ananatis parasitization ofPPM to almost halfofthat recorded in its absence. Increased A. ananatis densities increased PPM parasitization in the presence ofBHA, which suggested that augmentative field releases might help suppress PPM even when ants are present. The disruptive effects ofBHA on A. ananatis parasitism could potentially be neutralized by doubling (via augmentative release) the densities ofA. ananatis that provide effective PPM suppression in the absence ofBHA. The most common weed hosts ofPPM included rhodes grass, Chloris gayana, and wire grass, Eleusine indica, which were found in both mowed and unrnowed weed bands within disturbed areas around pineapple plantings. No mealybugs collected from these weeds produced parasitoids. vii TABLE OF CONTENTS ACKNOWLEDGEMENTS v ABSTRACT vi TABLE OF CONTENTS viii LIST OF TABLES xii LIST OF FIGURES xv I. INTRODUCTION 1 References 4 lI. LITERATURE REVlEW 8 Arthropod Pests ofPineapple 9 Mealybugs as Crop Pests 10 Mealybug Wilt ofPineapple 12 Dysmicoccus brevipes (Cockerell) 14 Pineapple Mealybug Wilt Associated Virus and Etiology ofMWP 17 Ants and MWP 19 Pineapple Mealybug Wilt Control. 21 Biological Control 24 Biological Control ofMealybugs 32 Factors Affecting Augmentative Biological Control 36 Biological Control Approaches for Dysmicoccus brevipes 37 Conclusions 38 References 40 III. ENHANCED PRODUCTION OF PINK PINEAPPLE MEALYBUG, DYSMICOCCUS BREVIPES (COCKERELL), (HOMOPTERA: PSEUDOCOCCIDAE) ........................................................................................................................................... 57 Introduction 57 Materials and Methods 61 viii Estimation ofHoneydew Production 62 Suitability ofVermiculite and Two Squash Varieties for PPM Production 64 Suitability ofPlastic and Paper Containers as Rearing Units 67 Optimum PPM Stage for Initial Squash Infestation 68 Results 70 Quantification ofHoneydew Production 70 Suitability ofVermiculite and Two Squash Varieties for PPM Production 72 Suitability ofPlastic and Paper Containers as Rearing Units 77 Optimum PPM Stage for Initial Squash Infestation 81 Discussion 86 References 92 IV. BIOLOGICAL PARAMETERS OF ANAGYRUS ANANATIS GAHAN (HYMENOPTERA: ENCYRTIDAE) 96 Introduction 96 Materials and Methods 99 Factors Affecting Parasitoid Longevity 99 Periodicity ofBiological Events 102 Results 104 Factors Affecting Parasitoid Longevity 104 Biological Events III Discussion 114 Conclusions 117 References 119 V. EFFECT OF PINK PINEAPPLE MEALYBUG HOSTS ON THE SIZE AND PROGENY PRODUCTION OF ANAGYRUS ANANATIS GAHAN (HYMENOPTERA: ENCYRTIDAE) 125 Introduction 125 Materials and Methods 127 Influence ofMealybug Size on Parasitoid Size and Sex 127 ix Influence ofParasitoid Size on Progeny Production 129 Results 132 Influence ofHost Size on Parasitoid Size and Sex 132 Influence ofParasitoid Size on Progeny Production 137 Discussion 143 Conclusions 148 References 149 VI. DEVELOPMENT OF ANAGYRUSANANATIS GAHAN (HYMENOPTERA: ENCYRTIDAE) AT CONSTANT TEMPERATURES 154 Introduction 154 Materials and Methods 157 Developmental Threshold 158 Biological Development ofAnagyrus ananatis 161 Results 162 Developmental Threshold 162 Biological Development ofAnagyrus ananatis 169 Discussion 173 Conclusions 179 References 181 VII. STORAGE OF ANA GYRUS ANANATIS GAHAN (HYMENOPRTERA: ENCYRTIDAE) IMMATURES AT COOL TEMPERATURES 186 Introduction 186 Materials and Methods 189 Survival ofCool Storage and adult longevity 189 Progeny Production 191 Results 192 Survival ofCool Storage 192 Identification of Stages Not Surviving Cool Storage 194 Effects on Developmental Time and Adult Longevity 196 x Progeny Production 202 Discussion 202 Conclusions 207 References 209 VIII. THE IMPACT OF BIG HEADED ANT ON ANAGYRUSANANATIS GAHAN (HYMENOPTERA: ENCYRTIDAE) PARASITISM OF THE PINK PINEAPPLE MEALYBUG 213 Introduction 2I3 Materials and Methods 216 Results and Discussion 220 References 227 IX. SURVEY FOR PINK PINEAPPLE MEALYBUG AND ASSOCIATED PARASITOIDS IN WEEDS BORDERING PINEAPPLE PLANTINGS 232 Introduction 232 Materials and Methods 235 Results 241 Discussion 253 References 255 X. SUMMARY AND RECOMMENDATIONS 258 PPM Mass Production 258 Biological Parameters ofAnagyrus ananatis 259 Overcoming the Impact ofAnts 261 Survey ofWeeds Around Pineapple Plantings 262 Future Research Recommendations 262 xi LIST OF TABLES Table 2. 1. Parasitoids introduced to Hawaii to control Dysmicoccus mealybugs 25 Table 2. 2. Predators introduced to Hawaii for the control ofDysmicoccus mealybugs ..26 Table 3. I. Production ofpink pineapple mealybug on butternut and Kobocha squash varieties with and without vermiculite provided in the rearing container to absorb honeydew 76 Table 3. 2. Effect ofplastic and paper containers on the laboratory rearing ofpink pineapple mealybug 80 Table 3.3. Effect ofinitial PPM infestation on PPM production in the laboratory 87 Table 4. I. Effects ofwater and honey on Anagyrus ananatis adult longevity 105 Table 4. 2. Impact ofhoney concentration on adult female Anagyrus ananatis longevity 106 Table 4. 3. Effect ofstarvation on adult female Anagyrus ananatis longevity 107 Table 4. 4. Effect ofprior feeding on honey on the progeny production and post- feeding longevity ofAnagyrus ananatis 109 Table 4. 5. Photophase and scotophase influence on rate ofAnagyrus ananatis oviposition as indicated by adult emergence from parasitized PPM 110 Table 4. 6. Adult emergence ofAnagyrus ananatis during specific time intervals I 12 Table 5. I. Effect ofmealybug size and source on adult Anagyrus ananatis length 133 Table 5. 2. Effect ofmealybug host