FUNGI ASSOCIATED WITH THE GLASSY-WINGED SHARPSHOOTER, Homalodisca coagulata, IN ITS NATIVE RANGE By S. ELIE BREAUX A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE UNIVERSITY OF FLORIDA 2005 Copyright 2005 by S. Elie Breaux This document is dedicated to Stefanie, always there. ACKNOWLEDGMENTS I would like to thank the members of my committee for their support, perseverance, and knowledge. I consider myself lucky to have found in them the willingness to take a chance on a student. I would like to thank Dr. Linda Young for extensive assistance in the statistical analysis portion of this study. I would also like to thank my family. My father has always been a student of nature. Raised with his love of the outdoors, the choice to take this path was made without reservation. My mother has always provided every kind of support a son could ask for, free of expectation or judgment. I thank Nicholas and Silas for being so entertaining. They are so different in nature, but time spent with either of them makes one realize what is important. And finally, I would like to thank Stefanie. Always generous with encouragement and unwavering in support, there is no way I could have done this without her. iv TABLE OF CONTENTS page ACKNOWLEDGMENTS ................................................................................................. iv LIST OF TABLES............................................................................................................ vii LIST OF FIGURES ......................................................................................................... viii ABSTRACT....................................................................................................................... ix CHAPTER 1 LITERATURE REVIEW.............................................................................................1 Homalodisca coagulata................................................................................................1 Feeding Behavior and Nutritional Ecology of Homalodisca coagulata .....................5 Homalodisca coagulata as a Disease Vector................................................................7 Homalodisca coagulata Vector Capacity..............................................................7 Xylella fastidiosa ...................................................................................................8 Potential Natural Control Agents................................................................................10 Parasites and Predators........................................................................................10 Fungal Pathogens of Auchenorrhyncha...............................................................11 Homalodisca coagulata -Associated Fungi.........................................................13 2 INTRODUCTION ......................................................................................................20 3 MATERIALS AND METHODS ...............................................................................22 Homalodisca coagulata/Hirsutella homalodiscae Interactions in a Crape Myrtle Field Plot................................................................................................................22 Description of Study Site.....................................................................................22 Sampling Program...............................................................................................22 Sticky Trap Grid..................................................................................................24 Diagnostic Bleeds .......................................................................................................25 Sampling Program...............................................................................................25 Bleed Technique..................................................................................................25 Statistical Analysis......................................................................................................26 4 RESULTS...................................................................................................................28 v 5 DISCUSSION.............................................................................................................41 6 CONCLUSIONS ........................................................................................................47 APPENDIX A SAS PROGRAMMING CODE FOR REPEATED MEASURES ANALYSIS OF LIVE GWSS POPULATIONS AND LEAST MEANS SQUARED ANALYSIS OF SIGNIFICANT EFFECTS ...................................................................................48 B SAS PROGRAMMING CODE FOR REPEATED MEASURES ANALYSIS OF CADAVER INCIDENCE AND LEAST MEANS SQUARES ANALYSIS OF SIGNIFICANT EFFECTS..........................................................................................50 C SAS PROGRAMMING CODE FOR REPEATED MEASURES ANALYSIS OF TRAP POPULATION DATA AND LEAST MEANS SQAURES ANALYSIS OF THE EFFECT OF TIME ......................................................................................52 D SAS PROGRAMMING CODE FOR REPEATED MEASURES ANALYSIS OF ARCSINE TRANSFORMED LIVE GWSS/CADAVER PROPORTIONS WITH LEAST MEANS SQUARE ANALYSIS OF SIGNIFICANT EFFECTS .................53 E QUINCY NFREC WEATHER DATA FOR 2004 AND 2005..................................55 F RAW DATA FROM 2004 AND 2004 FIELD STUDIES .........................................57 2004 Field Plot Data ...................................................................................................57 2005 Field Plot Data ...................................................................................................64 LIST OF REFERENCES...................................................................................................91 BIOGRAPHICAL SKETCH .............................................................................................98 vi LIST OF TABLES Table page 1 Comparison of 2004 and 2005 GWSS populations in field plot for same trees on same week between years. .......................................................................................28 2 Weeks with significantly higher trap catches of GWSS in 2005. ............................38 3 Significant differences in live GWSS numbers between cultivars with respect to treatment and week in 2005. ....................................................................................38 4 Significant differences between treatments with respect to week and cultivar in 2005..........................................................................................................................39 5 Significant differences in cadaver incidence between treatments for a given week and cultivar in 2005. .......................................................................................39 6 Significant differences in cadaver incidence between cultivars for a given week and treatment in 2005...............................................................................................40 vii LIST OF FIGURES Figure page 1 Light micrographs of mycosed glassy-winged sharpshooters displaying the three major phenotypes. ....................................................................................................16 2 Micrographs of the Pseudogibellula dissected from mycosed H. coagulata...........17 3 Sporothrix isolated from mycosed H. coagulata. ....................................................18 4 Light and electron micrographs of the Hirsutella. ...................................................19 5 Representative map of crape myrtle field plot. ........................................................23 6 Photographs of bleeding procedure..........................................................................26 7 Mean GWSS per yellow stick trap in 2005..............................................................29 8 Mean GWSS per tree for each cultivar in the first irrigated replicate......................32 9 Mean GWSS per tree for each cultivar in the second irrigated replicate.................33 10 Mean GWSS per tree for each cultivar in the first dry replicate..............................34 11 Mean GWSS per tree for each cultivar in the second dry replicate. ........................35 12 Mean GWSS per tree for entire plot.........................................................................36 13 Total GWSS cadavers observed by week. ...............................................................37 viii Abstract of Thesis Presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Master of Science FUNGI ASSOCIATED WITH THE GLASSY WINGED SHARPSHOOTER, Homalodisca coagulata, IN ITS NATIVE RANGE By S. Elie Breaux December, 2005 Chair: Drion G. Boucias Cochair: Russell F. Mizell III Major Department: Entomology and Nematology The glassy-winged sharpshooter (GWSS), Homalodisca coagulata (Say), is an efficient vector of the phytopathogenic bacterium Xyllela fastidiosa. Native to the Southeast U.S., it was introduced to California, where its presence has caused a sharp increase in X. fastidiosa-based disease. A complex of three possible fungal pathogens are associated with the glassy-winged sharpshooter in its native range: Pseudogibellula, Sporothrix, and Hirsutella. In the summer seasons of 2004 and 2005, a variety of cultivars were selected from a crape myrtle field plot and were used to