The Egg Stacking Strategy: Reproductive Plasticity in Response to Egg Parasitism in Mimosestes Amicus Item Type text; Electronic Dissertation Authors Deas, Joseph Benjamin, Jr. Publisher The University of Arizona. Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. Download date 27/09/2021 17:10:54 Link to Item http://hdl.handle.net/10150/293440 1 THE EGG STACKING STRATEGY: REPRODUCTIVE PLASTICITY IN RESPONSE TO EGG PARASITISM IN MIMOSESTES AMICUS By Joseph Benjamin Deas, Jr. __________________________ A Dissertation Submitted to the Faculty of the GRADUATE INTERDISCIPLINARY PROGRAM IN INSECT SCIENCE In Partial Fulfillment of the Requirements For the Degree of DOCTOR OF PHILOSOPHY In the Graduate College THE UNIVERSITY OF ARIZONA 2013 2 THE UNIVERSITY OF ARIZONA GRADUATE COLLEGE As members of the Dissertation Committee, we certify that we have read the dissertation prepared by Joseph B. Deas, Jr. entitled “The Egg Stacking Strategy: Reproductive Plasticity In Response To Egg Parasitism By Mimosestes amicus” and recommend that it be accepted as fulfilling the dissertation requirement for the Degree of Doctor of Philosophy. _____________________________________________ Date: April 5, 2013 Martha S. Hunter _____________________________________________ Date: April 5, 2013 Judith L. Bronstein _____________________________________________ Date: April 5, 2013 Goggy Davidowitz _____________________________________________ Date: April 5, 2013 Daniel R. Papaj Final approval and acceptance of this dissertation is contingent upon the candidate’s submission of the final copies of the dissertation to the Graduate College. I hereby certify that I have read this dissertation prepared under my direction and recommend that it be accepted as fulfilling the dissertation requirement. _____________________________________________ Date: April 5, 2013 Dissertation Director: Martha S. Hunter 3 STATEMENT BY AUTHOR This dissertation has been submitted in partial fulfillment of requirements for an advanced degree at the University of Arizona and is deposited in the University Library to be made available to borrowers under rules of the Library. Brief quotations from this dissertation are allowable without special permission, provided that accurate acknowledgment of source is made. Requests for permission for extended quotation from or reproduction of this manuscript in whole or in part may be granted by the author. SIGNED______________________________________Joseph B. Deas, Jr. 4 ACKNOWLEDGEMENTS The completion of this dissertation was dependent upon the support of many people, with my dissertation committee as the primary endorsers of my graduate education. I would first like to thank my dissertation advisor, Martha S. Hunter, for her patience in allowing me to pursue a project that was peripheral to the research program she already had established in her laboratory. Our overlapping interests in host-parasitoid interactions and the charisma of my study system maintained a productive mentorship, in which I learned how to establish the system for future studies and properly write and communicate my research to others. Judith L. Bronstein was also instrumental in my training, in that she consistently instilled in me the need to establish “the big question” as I investigated a particular problem. In addition to allowing me borrow a lot of lab equipment, Goggy Davidowitz brought much excitement and ideas to the development of my project, often prefacing his brainstorms with, “do you know what would be cool?” Dan Papaj contains a wealth of knowledge on insect reproduction, which I underused, but I was able to use his expertise to hone my reasoning and simplify or make elegant an experiment of convoluted design. Due to the extraneous nature of my dissertation in the Hunter Lab, I sought the knowledge and expertise of other researchers, collaborators, and PhDs. Through the introduction by Judie and Molly, Charles W. Fox and his study system were instrumental in inspiring me to focus current and future work on the evolution and maintenance of reproductive plasticity, using seed beetles as a model system. I would also like to thank Geoffrey E. Morse for systematic, phylogenetic, and natural history information on seed beetles; Bernard D. Roitberg and Jay Rosenheim for helping me understand the costs of reproduction in insects; Heather Henter and Richard Stouthamer for helping me identify and use egg parasitoids in my experiments. Associate Dean Maria Teresa Velez has been an unstoppable force in encouraging myself and other graduate students in achieving our dreams. I have made many friends along the way who have kept me sane and thinking the right way: Tuan Cao, Ming Huang, Kristen Potter, Bryan Helm, Latifa Jackson, Bodil Cass and members of the Hunter Lab and Bronstein Lab Group have assisted in field collection or engaged me in helpful discussion. Suzanne Kelly has been very patient and supportive in regards to all of the problems with my beetle colonies. Matt Trausch, his 2011 6th grade class, Hendricks Elementary, and the BioME staff for allowing me the opportunity to see the value in educating our youth and awaken my natural, inner teacher. I also thank Zakee Sabree, Chinedu Nworu, Jenny Jandt, David Morales, Vince Martinson, Ellen Suurmeyer, Ming-min Lee, Aaron Beyerlein, Michele Lanan, and the Black Graduate Student Association. A special thanks goes to Tucson Scrabble Brunch friends Matt Peters, Alica Espinoza, Kyle Kulakowski, Jenny Barker, and again, Bryan Helm. I am also grateful to the staff of the Center of Insect Science and Department of Entomology (especially Sharon Richards, 5 Teresa Kudrna, MaryLou Stengel), and the Graduate College. There are others I am grateful for that are unmentioned, but I only have room for those that I both knew the longest and who I was influenced by the most. Financial support for my dissertation came from the National Science Foundation (Graduate Research Fellowship, BioME GK-12 Fellowship, Doctoral Dissertation Improvement Grant), the Ford Foundation (Dissertation Fellowship), University of Arizona Graduate College (Marshall Foundation Dissertation Fellowship), Arizona State University MGE@MSA, Theodore Roosevelt Memorial Fund, Lewis and Clark Fund for Exploration and Research, and the Center for Insect Science. Lastly, I want to thank my entire family, all who have eternally supported me. That includes the unconditional love from the army of aunts, uncles, and cousins in South Carolina; the immeasurable love and from my mother, Lisa Deas and my father, Joseph Deas Sr.; and finally, my older sister Stacye Letman, with whom I have created the strongest bond as I have matured as an adult. 6 DEDICATION I dedicate this to the women in my family, who have demonstrated extraordinary resilience to the toughest hardships we may experience in life. This includes my mother, Lisa Deas; my sister, Stacye Letman; my aunts Victoria, Zelma, Mary, Emma Lee, Bertha Mae, and Sara; and my grandmothers Albertha and Helen. 7 TABLE OF CONTENTS ABSTRACT .......................................................................................................................8 I: INTRODUCTION .......................................................................................................10 II: PRESENT STUDY ......................................................................................................17 REFERENCES .................................................................................................................20 APPENDIX A. MOTHERS MODIFY EGGS INTO SHIELDS TO PROTECT OFFSPRING FROM PARASITISM ..................................................................27 APPENDIX B. THE SUNNY SIDE OF EGG STACKING: AVOIDANCE STRATEGIES IN RESPONSE TO MICROSPATIAL VARIATION IN EGG PARASITISM RISK ............................................................................................61 APPENDIX C. EGG AND TIME LIMITATION MEDIATE AN EGG PROTECTION STRATEGY ..............................................................................96 APPENDIX D. PERMISSIONS ...................................................................................131 8 ABSTRACT All organisms live in environments that are variable across space and time. Variation in selection across these environments may lead to the evolution of generalist genotypes that express phenotypic plasticity, in which one genotype can alter their phenotype (e.g., morphology, behavior, physiology) to match changes in environmental conditions, so that they may survive across a range of environments. In many egg-laying organisms that lack parental care, choosing an oviposition site is critical. The egg is an immobile stage of an animal’s life cycle and mothers must balance a complex set of risks in deciding where to place their eggs. Because many biotic and abiotic factors are sources of selection on offspring survival, there is an advantage for females to evolve strategies in oviposition site selection to improve survival. This dissertation focuses on phenotypic plasticity in an offspring protection strategy that is triggered by natural enemies. In the seed beetle Mimosestes amicus (Coleoptera: Chrysomelidae: Bruchinae), females lay eggs on the outside of seed pods of legume trees and beetle larvae bore into and develop