MULTITROPHIC INTERACTIONS AMONG CRAPEMYRTLES, Lagerstroemia spp., CRAPEMYRTLE APHIDS, Sarucallis kahawaluokalani, AND APHID PREDATORS By JOHN JOSEPH HERBERT A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA 2009 1 © 2009 John Joseph Herbert 2 To my wonderful loving parents David and Margaret Herbert 3 ACKNOWLEDGMENTS I thank my advisor Dr. Russell F. Mizell III for all the support he gave me for the past four years. Dr. Mizell has provided advice, guidance, and contributed significantly to my growth not only as a student, but as a person as well. Without his academic, emotional and monetary support, this research could not have been possible. I thank the members of my advisory committee Drs. Gary Knox, Heather McAuslane, and J. Howard Frank. My committee provided me with invaluable feedback and constructive advice on how to improve and achieve my academic and personal goals. I thank Tobin Northfield for helping me learn SADIE and helping with the plot design for the spatial experiment. Charles Riddle provided help with managing plots, preparing leaf disks, and sticky trap data collection. Cihangir Gokalp helped with aphid rearing and spent many nights in the laboratory helping me prepare leaf disks. Meghan Brennan and George Papageorgio helped arrange the most appropriate statistical analyses and aided with writing SAS code. I thank Dr. Karla Addesso for providing editorial advice. I thank Dawn Atchison for all the love, support, friendship, companionship, and compassion that she gave me, and my life has been enriched because of her. Leslie Rios is a dear friend who was there to support me whenever it was needed. Frank Wessels and Erin Vrzal taught me how to balance work and play. I thank my best friends from Ohio, Andy and Cindy Simmons, who have been there to support me for the last ten years of my academic career. I thank all of my other friends for contributing to my academic and personal growth. I thank my family, especially my parents, for giving me the values, morals, and work ethic to succeed in life. My sister Susan was instrumental in helping me through tough times. I thank my brother Mike, sisters, Ann, and Maria, and their families for all their love and support. 4 TABLE OF CONTENTS page ACKNOWLEDGMENTS ...............................................................................................................4 LIST OF TABLES...........................................................................................................................7 LIST OF FIGURES .......................................................................................................................10 ABSTRACT...................................................................................................................................13 CHAPTER 1 INTRODUCTION AND LITERATURE REVIEW ..............................................................15 Crapemyrtle Aphids................................................................................................................15 Tritrophic Interactions ............................................................................................................17 Crapemyrtle as an Augmentation Crop ..................................................................................19 Objectives ...............................................................................................................................21 2 HOST PREFERENCE OF THE CRAPEMYRTLE APHID Sarucallis kahawaluokalani (KIRKALDY) (HEMIPTERA: APHIDIDAE) AND HOST SUITABILITY OF CRAPEMYRTLE Lagerstroemia spp. CULTIVARS ...........................................................22 Introduction.............................................................................................................................22 Materials and Methods ...........................................................................................................24 No-Choice Experiment....................................................................................................24 Choice Experiment ..........................................................................................................26 Statistics...........................................................................................................................27 Results.....................................................................................................................................28 No-Choice Experiment....................................................................................................28 Choice Experiment ..........................................................................................................29 Discussion...............................................................................................................................30 No-Choice Experiment....................................................................................................30 Choice Experiment ..........................................................................................................31 Aphid Study.....................................................................................................................32 3 TRITROPHIC INTERACTIONS AMONG CRAPEMYRTLE, CRAPEMYRTLE APHIDS, AND THE GREEN LACEWING Chrysoperla rufilabris (BURMEISTER)........39 Introduction.............................................................................................................................39 Materials and Methods ...........................................................................................................41 Ad Libitum Experiment....................................................................................................41 Suboptimal Diet Experiment ...........................................................................................43 Results.....................................................................................................................................46 Ad Libitum Experiment....................................................................................................46 Suboptimal Diet Experiment ...........................................................................................47 5 Discussion...............................................................................................................................48 Ad Libitum Experiment....................................................................................................48 Suboptimal Diet Experiment ...........................................................................................50 Lacewing Study...............................................................................................................50 4 LANDSCAPE ECOLOGY OF THE CRAPEMYRTLE APHID AND THE APHID PREDATOR Harmonia axyridis (PALLAS) .........................................................................64 Introduction.............................................................................................................................64 Materials and Methods ...........................................................................................................66 Experimental Setup .........................................................................................................66 Sampling..........................................................................................................................67 Statistics...........................................................................................................................68 Results.....................................................................................................................................72 2007 Data.........................................................................................................................72 2008 Data.........................................................................................................................76 Discussion...............................................................................................................................79 Habitat Level Effects.......................................................................................................79 Cultivar Level Effects......................................................................................................81 Spatial Relationships .......................................................................................................81 Field Study.......................................................................................................................83 5 GENERAL CONCLUSIONS...............................................................................................110 Host Suitability and Host Preference....................................................................................110 Tritrophic Interactions ..........................................................................................................111 Spatial and Temporal Interactions........................................................................................114 Multitrophic Interactions ......................................................................................................115 APPENDIX A GIS MAPS............................................................................................................................118