University of Kentucky UKnowledge Theses and Dissertations--Entomology Entomology 2015 INVASIVENESS OF AN EXOTIC GALL WASP IS INFLUENCED BY INTERACTIONS WITH EXOTIC AND ENDEMIC ORGANISMS Ignazio Graziosi University of Kentucky, [email protected] Right click to open a feedback form in a new tab to let us know how this document benefits ou.y Recommended Citation Graziosi, Ignazio, "INVASIVENESS OF AN EXOTIC GALL WASP IS INFLUENCED BY INTERACTIONS WITH EXOTIC AND ENDEMIC ORGANISMS" (2015). Theses and Dissertations--Entomology. 15. https://uknowledge.uky.edu/entomology_etds/15 This Doctoral Dissertation is brought to you for free and open access by the Entomology at UKnowledge. It has been accepted for inclusion in Theses and Dissertations--Entomology by an authorized administrator of UKnowledge. For more information, please contact [email protected]. STUDENT AGREEMENT: I represent that my thesis or dissertation and abstract are my original work. Proper attribution has been given to all outside sources. I understand that I am solely responsible for obtaining any needed copyright permissions. I have obtained needed written permission statement(s) from the owner(s) of each third-party copyrighted matter to be included in my work, allowing electronic distribution (if such use is not permitted by the fair use doctrine) which will be submitted to UKnowledge as Additional File. I hereby grant to The University of Kentucky and its agents the irrevocable, non-exclusive, and royalty-free license to archive and make accessible my work in whole or in part in all forms of media, now or hereafter known. I agree that the document mentioned above may be made available immediately for worldwide access unless an embargo applies. I retain all other ownership rights to the copyright of my work. I also retain the right to use in future works (such as articles or books) all or part of my work. I understand that I am free to register the copyright to my work. REVIEW, APPROVAL AND ACCEPTANCE The document mentioned above has been reviewed and accepted by the student’s advisor, on behalf of the advisory committee, and by the Director of Graduate Studies (DGS), on behalf of the program; we verify that this is the final, approved version of the student’s thesis including all changes required by the advisory committee. The undersigned agree to abide by the statements above. Ignazio Graziosi, Student Dr. Lynne K. Rieske-Kinney, Major Professor Dr. Charles W. Fox, Director of Graduate Studies INVASIVENESS OF AN EXOTIC GALL WASP IS INFLUENCED BY INTERACTIONS WITH EXOTIC AND ENDEMIC ORGANISMS ______________________________ DISSERTATION ______________________________ A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the College of Agriculture, Food, and the Environment at the University of Kentucky By Ignazio Graziosi Lexington, Kentucky Director: Dr. Lynne K Rieske Kinney, Professor of Entomology Lexington, Kentucky 2015 Copyright © Ignazio Graziosi 2015 ABSTRACT OF DISSERTATION INVASIVENESS OF AN EXOTIC GALL WASP IS INFLUENCED BY INTERACTIONS WITH EXOTIC AND ENDEMIC ORGANISMS American chestnut was once a crucial component of North American forests, but it was functionally eliminated by the introduction of the chestnut blight fungus. Chestnut is recently experiencing resurgence, but the introduced Asian chestnut gall wasp, a specialist herbivore, threatens chestnut recovery. I characterized this invasion and the interactions developing with host associates as the gall wasp spread in North America. Gall wasp dispersal is attributable to host plant distribution, effects of prevailing winds during adult insect emergence, and to topography. This knowledge may be useful to more accurately predict locations of future gall wasp infestations. Gall wasp invasiveness is also affected by its ability to modulate reproduction and reallocate nutritive resources for body maintenance and egg quality. The gall wasp can form galls of different shape and structure based on population levels and parasitism pressure, in order to optimize fitness. Simple, uni-lobed galls are formed when population pressure is low, and complex, multi- lobed galls are formed when gall wasp populations are high. A fungal plant pathogen, identified as Colletotrichum sp., infects galls and acts as an opportunistic entomopathogen, causing gall wasp mortality while sparing the parasitoid. A non-native torymid parasitic wasp has been deployed for biological control. Using a Y-olfactometer I demonstrated that a combination of olfactory and visual cues from chestnut galls and chestnut foliage is required for parasitoid adults to locate hosts. In addition, I evaluated interactions between the gall wasp and stem cankers on chestnut. Using potted Chinese chestnut seedlings with or without gall wasp or a native Nectria cankering pathogen, I found that the gall wasp has a negative impact on plant fitness, and a positive impact on fungal fitness. My work helps elucidate ecological mechanisms underlying the success of the exotic Asian chestnut gall wasp in North America, and adds to our knowledge base characterizing evolving ecological interactions between native and introduced species. KEY WORDS: Castanea, Dryocosmus kuriphilus, invasiveness, host location, community associates Student’s signature Date INVASIVENESS OF AN EXOTIC GALL WASP IS INFLUENCED BY INTERACTIONS WITH EXOTIC AND ENDEMIC ORGANISMS By Ignazio Graziosi 2015 Dr. Lynne K. Rieske-Kinney Director of Dissertation Dr. Charles W. Fox Director of Graduate Studies 14 January 2015 Date ACKNOWLEDGMENTS This work has been possible thanks to the contributions of many individuals and institutions. I wish to thank my advisor and mentor Dr. Lynne Rieske-Kinney, for guiding me through my doctorate by providing constant support, motivation and advice. I also wish to thank former and current members of the lab, Luke Dodd, Josh Adkins, Lori Nelson, Melanie Sprinkle, Chris Strohm, Abe Nielsen, Bill Davidson and Matt Savage, for their friendship and help on many occasions. I would like to thank Dr. Demetrio Zourarakis for contributing to my GIS project, Julie Beale, Bernadette Amsden, and Paul Vincelli for help with fungal identification, Kristen McQuerry for statistical advice, and Gary Micsky and Greg Miller for field assistance. I thank the US-Italy Fulbright Commission in Rome for their interest and financial support to my project and also the Institute of International Education in Chicago for assistance. Funding for my research was also provided by the Tracy Farmer Institute for Sustainability and the Environment, the Center of Ecology Evolution and Behavior, McIntire Stennis Funds from the Kentucky Agricultural Experiment Station, the Northern Nut Growers Association, the American Chestnut Foundation and the USDA Forest Service. I would like to thank my research committee, Dr. Ken Haynes, Dr. John Obrycki, Dr. Charles Fox and Dr. Lou Shain, for their knowledgeable support to my research. Many thanks also to Dr. Graham Stone, from University of Edinburgh, who attended my dissertation defense and contributed valuable insights. Other sources of inspiration and advice came from Dr. Dan Potter and Dr. Lee Townsend in the Department of Entomology, and the NE-1333 Chestnut Research group, especially Dr. Fred Hebard, Dr. Sandra Anagnostakis and Dr. Hill Craddock. I would also like to thank the University of Kentucky Graduate School and the Department of Entomology for supporting my work. In addition I would like to thank all of the graduate students in the Department of Entomology, who shared with me these years. Finally, a special thanks to my parents Benedetto and Maria Gabriella Graziosi, my brothers Giacomo and Peter, and my sisters Caterina and Anna. iii TABLE OF CONTENTS Acknowledgments ......................................................................................................... iii Table of contents ........................................................................................................... iv List of tables .................................................................................................................. vi List of figures ............................................................................................................... vii Chapter One: Introduction ...............................................................................................1 Chapter Two: Local spread of an exotic invader: using remote sensing and spatial analysis to document proliferation of the invasive Asian chestnut gall wasp ....................7 Materials and methods ............................................................................................... 11 Results and discussion................................................................................................ 12 Conclusions ............................................................................................................... 16 Chapter Three: Potential fecundity of a highly invasive gallmaker, Dryocosmus kuriphilus (Hymenoptera: Cynipidae) ............................................................................ 26 Materials and methods ............................................................................................... 28 Results ....................................................................................................................... 29 Discussion and conclusions .......................................................................................