University of Windsor Scholarship at UWindsor Electronic Theses and Dissertations Theses, Dissertations, and Major Papers 2015 An experimental analysis of the effects of plant and prey quality on the life history and behaviour of Dicyphus hesperus Knight (Hemiptera: Miridae), an omnivorous biological control agent Meghan Ann Vankosky University of Windsor Follow this and additional works at: https://scholar.uwindsor.ca/etd Part of the Biology Commons, Entomology Commons, and the Plant Sciences Commons Recommended Citation Vankosky, Meghan Ann, "An experimental analysis of the effects of plant and prey quality on the life history and behaviour of Dicyphus hesperus Knight (Hemiptera: Miridae), an omnivorous biological control agent" (2015). Electronic Theses and Dissertations. 5715. https://scholar.uwindsor.ca/etd/5715 This online database contains the full-text of PhD dissertations and Masters’ theses of University of Windsor students from 1954 forward. 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An experimental analysis of the effects of plant and prey quality on the life history and behaviour of Dicyphus hesperus Knight (Hemiptera: Miridae), an omnivorous biological control agent By Meghan Ann Vankosky A Dissertation Submitted to the Faculty of Graduate Studies through the Department of Biological Sciences in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy at the University of Windsor Windsor, Ontario, Canada 2015 © 2015, Meghan Ann Vankosky An experimental analysis of the effects of plant and prey quality on the life history and behaviour of Dicyphus hesperus Knight (Hemiptera: Miridae), an omnivorous biological control agent By Meghan Ann Vankosky APPROVED BY: __________________________________________________ Dr. W.E. Snyder, External Examiner Department of Entomology, Washington State University, Pullman, WA __________________________________________________ Dr. K.G. Drouillard Great Lakes Institute for Environmental Research __________________________________________________ Dr. D.M. Higgs Department of Biological Sciences __________________________________________________ Dr. O.P. Love Department of Biological Sciences __________________________________________________ Dr. S.L. VanLaerhoven, Advisor Department of Biological Sciences 26 March, 2015 Declaration of Co-Authorship / Previous Publication I. Co-Authorship Declaration I hereby declare that this thesis incorporates material that is result of joint research, as follows: The general introduction (Chapter 1) and general conclusion (Chapter 7) were authored solely by me. The data chapters (Chapters 2 through 6) are co-authored by Dr. Sherah VanLaerhoven and myself. In all cases (Chapters 2 to 6) I developed the key ideas and experimental designs, and I analyzed and interpreted the data and prepared the manuscripts. Dr. Sherah VanLaerhoven contributed to the experimental design, manuscript editing, and provided funding and logistical support for the data collected and described in all five chapters. I am aware of the University of Windsor Senate Policy on Authorship and I certify that I have properly acknowledged the contribution of other researchers to my thesis, and have obtained written permission from each of the co-author(s) to include the above material(s) in my thesis. I certify that, with the above qualification, this thesis, and the research to which it refers, is the product of my own work. II. Declaration of Previous Publication This thesis includes two original papers that have been previously published/submitted for publication in peer reviewed journals, as follows: Thesis Chapter Publication title/full citation Publication status* Chapter 5 Are omnivores picky eaters? The prey In review by preference of Dicyphus hesperus, an Biological Control omnivorous biological control agent of greenhouse whitefly (Trialeurodes vaporariorum). Chapter 6 Plant and prey quality interact to influence the In revision for Animal foraging behaviour of an omnivorous insect, Behaviour Dicyphus hesperus iii I certify that I have obtained a written permission from the copyright owner(s) to include the above published material(s) in my thesis. I certify that the above material describes work completed during my registration as graduate student at the University of Windsor. I declare that, to the best of my knowledge, my thesis does not infringe upon anyone’s copyright nor violate any proprietary rights and that any ideas, techniques, quotations, or any other material from the work of other people included in my thesis, published or otherwise, are fully acknowledged in accordance with the standard referencing practices. Furthermore, to the extent that I have included copyrighted material that surpasses the bounds of fair dealing within the meaning of the Canada Copyright Act, I certify that I have obtained a written permission from the copyright owner(s) to include such material(s) in my thesis. I declare that this is a true copy of my thesis, including any final revisions, as approved by my thesis committee and the Graduate Studies office, and that this thesis has not been submitted for a higher degree to any other University or Institution. iv Abstract Dicyphus hesperus Knight (Hemiptera: Miridae) is an omnivorous natural enemy of greenhouse whitefly, Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae) that can be used in biological control programs. Omnivorous natural enemies consume both plant and prey food and offer certain advantages and disadvantages to biological control; therefore, understanding these species prior to their use is important. Much is currently known about D. hesperus. However, variation in the quality of plant and/or prey resources for consumers is common in agroecosystems. The impacts of varying within- species resource quality on D. hesperus have not been investigated. The objective of my dissertation was to investigate the effect of varying plant and prey quality on the life history and behaviour of D. hesperus. To approach this question, I used nitrogen (N) fertilizer to manipulate the quality of tomato plants, Solanum lycopersicum L. (Solanales: Solanaceae). Prey reared on high and low N tomato plants were offered in feeding trials to represent natural variation in prey quality. I observed how these factors, independently or simultaneously, affected oviposition preference (Chapter 2); development and survival of D. hesperus nymphs (Chapter 3); olfactory response (Chapter 4); prey preference and consumption rate (Chapter 5); and the activity budget (Chapter 6) of D. hesperus. Based on optimal oviposition theory, optimal foraging theory, and the plant vigor and plant stress hypotheses, I predicted that high N tomato plants, and whitefly prey reared on those plants, would be most preferred. I also predicted that the behaviour of D. hesperus would vary in response to the quality of the resources available. As expected, both factors influenced the life history and behaviour of D. hesperus. For example, high N tomatoes were preferred for oviposition and prey reared on high N plants were preferred for consumption. Foraging behaviour of D. hesperus adults also varied in response to varying levels of plant N when prey from high and low N tomatoes were provided. My results can be used to inform the development of biological control programs using omnivores, and D. hesperus in particular. My research highlights the importance of considering within- species variation in quality when making pest management decisions. v Dedication To my parents, Gary and Marion, My siblings, Mallary and Gavin, and Grannie Annie. Thank you for everything. In Loving Memory of Macey Vankosky (August 31, 1992 – January 12, 2011) and Dr. Lloyd Dosdall (July 21, 1952 – June 12 2014). vi Acknowledgements I have a rather long list of people to acknowledge. Without these people, my thesis might not have happened and I might not be the same person I am today. I am grateful to Dr. Sherah VanLaerhoven for the opportunity to study entomology as a member of her lab at the University of Windsor, and for her unwavering support, encouragement, and mentorship. It has been an honour to work with Sherah. In particular, Sherah gave me the freedom to approach this project as I have, and her faith in my abilities has meant more than I can say. For their guidance, support, and patience, I thank my committee members, Dr. Ken Drouillard, Dr. Dennis Higgs, and Dr. Oliver Love. I would also like to thank Dr. Lynda Corkum for her contribution to my thesis committee prior to her retirement and for her friendship. I also extend my gratitude to Dr. Bill Snyder for agreeing to serve as my external examiner and for travelling here from Washington State University to do so. I thank the faculty and staff in the Department of Biological Sciences for their various contributions to my degree. Everyone here is friendly, approachable,