Louisiana State University LSU Digital Commons LSU Doctoral Dissertations Graduate School 2007 Population ecology of Pseudacteon tricuspis Borgmeier (Diptera: Phoridae), an introduced parasitoid of the red imported fire ant Solenopsis invicta Buren (Hymenoptera: formicidae) in Louisiana Donald Charles Henne Louisiana State University and Agricultural and Mechanical College, [email protected] Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_dissertations Part of the Entomology Commons Recommended Citation Henne, Donald Charles, "Population ecology of Pseudacteon tricuspis Borgmeier (Diptera: Phoridae), an introduced parasitoid of the red imported fire ant Solenopsis invicta Buren (Hymenoptera: formicidae) in Louisiana" (2007). LSU Doctoral Dissertations. 378. https://digitalcommons.lsu.edu/gradschool_dissertations/378 This Dissertation is brought to you for free and open access by the Graduate School at LSU Digital Commons. It has been accepted for inclusion in LSU Doctoral Dissertations by an authorized graduate school editor of LSU Digital Commons. For more information, please [email protected]. POPULATION ECOLOGY OF PSEUDACTEON TRICUSPIS BORGMEIER (DIPTERA: PHORIDAE), AN INTRODUCED PARASITOID OF THE RED IMPORTED FIRE ANT SOLENOPSIS INVICTA BUREN (HYMENOPTERA: FORMICIDAE) IN LOUISIANA A Dissertation Submitted to the Graduate Faculty of the Louisiana State University and Agricultural and Mechanical College in partial fulfillment of the requirements for the degree of Doctor of Philosophy in The Department of Entomology by Donald Charles Henne B.S., University of Manitoba, 1995 M.S., University of Manitoba, 2000 December 2007 ACKNOWLEDGEMENTS In pursuing this Ph.D., I was well aware that I was faced with an enormous challenge. The study described herein required an exploration of many diverse areas of science to obtain explanations and solutions to understand the patterns that I found, and to comprehend the mysterious quantitative ecological literature. These digressions were the source of focused study of mathematics, statistics, ecology, insect behavior, meteorology, and other esoteric topics. First, I am sincerely indebted to my major professor, Dr. Seth Johnson, for taking a calculated risk in employing me as his research associate and giving me the autonomy to pursue this Ph.D. as his graduate student. His assistance in the field, friendship, wisdom, patience, encouragement and guidance throughout our collaborations will be forever appreciated. I would also like to express my sincerest appreciation to the members of my graduate committee: Drs. Jim Cronin, Gregg Henderson and Tim Schowalter. I could not have imagined a more fitting choice of scientists to serve as advisors and mentors. In choosing the members of my committee, I selected those whom I determined were not only compatible with my research objectives, but who are also exceptional scientists and mentors. Their success is a source of inspiration for me and I thank them for treating me as a colleague. My growth and trajectory as a scientist has been influenced by many professional and personal interactions, and I am proud to say that I have known these men. I would also like express thanks to Dr. Zhijun Liu for his efforts as Dean‟s Representative on my committee. I want to express appreciation to the following individuals for assistance in the field and for doing PCR work: Van Hilbun, Lacey Inmon and Sunil Tewari. A special ii thanks is extended to Debbie Roberts (USDA-ARS) for providing numerous parasitoids that were critical for my research. Gratitude is expressed to the LSU Agricultural Center for allowing me to pursue a part-time graduate degree while also working as a research associate, and for assistance with coursework, visa and fee issues. To my parents, Doug and Pat Henne, whose love, patience, guidance and encouragement have been the light of my career. Their interest in my professional and personal development has been a source of motivation. Finally, it would be remiss of me not to mention the critical support of my wife, Chanda. Her love, support and encouragement during this endeavor were decisive factors when times of depression or sloth set in. Her understanding of the rigors of graduate student life made this a much smoother journey. Her comments on earlier versions of this dissertation were valuable. I dedicate this dissertation to her. iii TABLE OF CONTENTS ACKNOWLEDGMENTS………………………………………………………………..ii ABSTRACT……………………………………………………………………………viii CHAPTER 1 INTRODUCTION AND LITERATURE REVIEW……………………………………1 Introduction……………………………………………………….……………..2 Review of the Literature…………………..…………………………………….4 Phorid Flies……………………………………………………………………4 Behavior and Fate of Parasitized Fire Ant Hosts……………………………..4 Aggregation and Mutual Interference…………………………………………5 Spatial and Temporal Abundance Patterns..…………………………………..6 Dispersal and Spread………………………………………………………….7 Daily and Seasonal Dynamics...………………………………………………7 Studies in Louisiana……………………………………………………………..9 Significance of Study...………………………………………………………...10 References……………………………………………………………………...11 2 ZOMBIE FIRE ANT WORKERS: BEHAVIOR CONTROLLED BY DECAPITATING FLY PARASITOIDS…………………………………………..17 Introduction…………………………………………………………………….18 Materials and Methods………………………………………………………....20 Results………………………………………………………………………….23 Discussion……………………………………………………………………...25 References……………………………………………………………………...27 3 LABORATORY EVALUATION OF AGGREGATION, DIRECT MUTUAL INTERFERENCE AND FUNCTIONAL RESPONSE CHARACTERISTICS OF THE DECAPITATING FLY, PSEUDACTEON TRICUSPIS BORGMEIER (DIPTERA: PHORIDAE)……………………………….………………..………...30 Introduction…………………………………………………………………….31 Materials and Methods………………………………………………………....34 A) Aggregative Responses……………...……...…………………………….35 Statistical Analysis…………………………………………...…………….36 B) Direct Mutual Interference……………...………………………………...36 Male Interference……...…………………………………………………...39 Statistical Analysis……...………...………………………………………..39 C) Functional Response…………...…………...…………………………….40 Statistical Analysis.……...…………………………………………...…….41 Results.…………………………………………………………………………42 Aggregative Responses of P. tricuspis….…..…………...…………………..42 Direct Mutual Interference…………………...………………………………44 Total Hosts Parasitized…………..…………………………………..…….44 Searching Efficiency………...…………………………………………..…46 iv Male Interference………………………………………………..…………47 Functional Response…………...…………………………………………..47 Discussion……………………………………………………………………...50 Aggregative Responses…………………………………….…………..….....50 Direct Mutual Interference………………………………………………...…52 Male Interference…..…………………………………………………...……53 Functional Response……...………………………………………………….54 Conclusions…………………………………………………………………….55 References……………………………………………………………………...55 4 SPATIO-TEMPORAL DYNAMICS OF THE DECAPITATING FLY, PSEUDACTEON TRICUSPIS BORGMEIER (DIPTERA: PHORIDAE) AT THREE LOCATIONS IN LOUISIANA………………………………………………………………………..60 Introduction…………………………………………………………………….61 Materials and Methods………………………………………………………....63 Study Locations……..………………………………………...……………..63 Sampling P. tricuspis………………………………………...………………64 Determination of Social Form and Presence of Thelohania…………….…...65 Analysis of P. tricuspis Spatial Distributions…………..………..….……….65 Results………………………………………………………………………….68 T. solenopsae infection and P. tricuspis………………………………...…...68 Social Form and P. tricuspis…………...……………………………...……..68 Spatio-temporal Distribution of P. tricuspis…………...…………………….69 Discussion……………………………………………………………………...79 References……………………………………………………………………...82 5 QUANTIFYING LOCAL MOVEMENT OF THE DECAPITATING FLY, PSEUDACTEON TRICUSPIS BORGMEIER (DIPTERA: PHORIDAE), FROM POINT RELEASE EXPERIMENTS……………………………………………….86 Introduction…………………………………………………………………….87 Materials and Methods………………………………………………………....90 Study Organism……...………………………………………...…………….90 Pre-trial Dispersal Surveys..……………………………………...………….91 Dispersal Trials: Experimental Design……….……………………...………92 Dispersal Distances of Fly Sexes…………..…………………………...……96 Statistical Analyses…...………………………………………………….......97 Description of Density-Distribution Curve and Fit of Dispersal to a Null Diffusion Model……………………………..……………………………..98 Results……………………………………………………………………..….101 Dispersal at Natchitoches Releases…………...…………………….……....101 Montpelier Trials………………………………………………….…......…102 Recapture Rates and Fit of Movement to a Null Diffusion Model…..…..…103 Discussion…………………………………………………………………….108 References…………………………………………………………………….112 v 6 POPULATION SPREAD OF THE INTRODUCED RED IMPORTED FIRE ANT PARASITOID, PSEUDACTEON TRICUSPIS BORGMEIER (DIPTERA: PHORIDAE), IN LOUISIANA…………………………………………………...116 Introduction…………………………………………………………………...117 Materials and Methods………………………………………………………..119 Biology of Pseudacteon Parasitoids…………...……………...……………119 Release Sites…………………………………………………...…...………120 Evaluating Population Expansion……..……….………………...…………120 Modeling P. tricuspis Range Expansion……..……………………...……...121 Average Radius of Spread………..…………………………..…………..121 Annual Spread Rates…….………………………..……………………...122 Decline of P. tricuspis Away From Release Points……...……………….123 Results………………………………………………………………………...123 P. tricuspis Range Expansion…………………………..……………...…...123 Decline of P. tricuspis Away from Release Points……...…………..……...127 Discussion…………………………………………………………………….127 References…………………………………………………………………….134 7 DAILY AND SEASONAL DYNAMICS OF THE DECAPITATING FLY, PSEUDACTEON TRICUSPIS BORGMEIER (DIPTERA: PHORIDAE) IN LOUISIANA………………………………………………………………………140 Introduction…………………………………………………………………...141 Materials