University of Massachusetts Amherst ScholarWorks@UMass Amherst Doctoral Dissertations Dissertations and Theses October 2018 IMPACT OF NATIVE NATURAL ENEMIES ON POPULATIONS OF THE INVASIVE WINTER MOTH (OPEROPHTERA BRUMATA L) IN THE NORTHEAST UNITED STATES Hannah J. Broadley University of Massachusetts Amherst Follow this and additional works at: https://scholarworks.umass.edu/dissertations_2 Part of the Entomology Commons, Other Ecology and Evolutionary Biology Commons, and the Population Biology Commons Recommended Citation Broadley, Hannah J., "IMPACT OF NATIVE NATURAL ENEMIES ON POPULATIONS OF THE INVASIVE WINTER MOTH (OPEROPHTERA BRUMATA L) IN THE NORTHEAST UNITED STATES" (2018). Doctoral Dissertations. 1327. https://doi.org/10.7275/12760419 https://scholarworks.umass.edu/dissertations_2/1327 This Open Access Dissertation is brought to you for free and open access by the Dissertations and Theses at ScholarWorks@UMass Amherst. It has been accepted for inclusion in Doctoral Dissertations by an authorized administrator of ScholarWorks@UMass Amherst. For more information, please contact [email protected]. IMPACT OF NATIVE NATURAL ENEMIES ON POPULATIONS OF THE INVASIVE WINTER MOTH (OPEROPHTERA BRUMATA L) IN THE NORTHEAST UNITED STATES A Dissertation Presented by HANNAH J. BROADLEY Submitted to the Graduate School of the University of Massachusetts Amherst in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY September 2018 Graduate Program in Organismic and Evolutionary Biology © Copyright by Hannah J. Broadley 2018 All Rights Reserved IMPACT OF NATIVE NATURAL ENEMIES ON POPULATIONS OF THE INVASIVE WINTER MOTH (OPEROPHTERA BRUMATA L) IN THE NORTHEAST UNITED STATES A Dissertation Presented by HANNAH J. BROADLEY Approved as to style and content by: ____________________________________ Joseph S. Elkinton, Chair ____________________________________ Lynn S. Adler, Member ____________________________________ John P. Burand, Member ____________________________________ Benjamin B. Normark, Member ____________________________________ Paige S. Warren, Program Leader Organismic and Evolutionary Biology ____________________________________ Patricia WadsWorth, Director Interdepartmental Programs in Life Science DEDICATION for the trees and forests ACKNOWLEDGMENTS First and foremost, I’d like to acknowledge Joe Elkinton, for without him, none of this would have been possible. I also sincerely thank George Boettner, Adam Pepi, Jeremy Andersen, Rodger GWiazdowski, Theresa Murphy, Monica Davis, Ryan Crandall, Katelyn Donahue, Natashia Manyak, Nelson Milano, Artemis Roehrig, Brenna Fleming, Rich Hennessy, Emily Kelly, Tessa Dowling, Quentin Dupupet, Chris Camp, Emily Mooshian, Erik Lee, Genn Greenberg, Julia Cox, Brian Griffin, Cameron Smith- Freedman, Alexyss Langevin, Brenda Whited Schneider, Aaron Weed, Jeff Lombardo, and Leah Flaherty from the Elkinton lab for their contribution to this research. I would like to thank Roy Van Driesche, MattheW Boucher, Woojin Kim, Lina Tian, Rose Zheng, Robert Kula, Bernardo Santos, Andy Bennett, Nathan Havill, Tero Klemola, Deborah SWanson, Richard Casagrande, Don and Cheryl Adams, Ellen Amore, Tom Peckham, Heather Faubert, and Charlene Donahue for their collaboration. Thank you to my committee Lynn Adler, John Burand, and Benjamin Normark. Thank you to the OEB program and thank you to the constant support of my friends and family. This research was supported by Cooperative Agreements from the USDA APHIS [12 13 14-8225-0464-CA] and from the USDA Forest Service [13-CA-1140004-236-CA] as well as a Summer Research Scholarship from the University of Massachusetts Amherst Natural History Collections, a fieldwork grant and a dissertation research grant from the University of Massachusetts Amherst Graduate School, and an Irwin Martin AWard from the Graduate Program in Organismic and Evolutionary Biology, University of Massachusetts Amherst. v ABSTRACT IMPACT OF NATIVE NATURAL ENEMIES ON POPULATIONS OF THE INVASIVE WINTER MOTH (OPEROPHTERA BRUMATA L) IN THE NORTHEAST UNITED STATES SEPTEMBER 2018 HANNAH J. BROADLEY, B.S., BATES COLLEGE M.S., UNIVERSITY OF MASSACHUSETTS AMHERST Ph.D., UNIVERSITY OF MASSACHUSETTS AMHERST Directed by: Professor Joseph S. Elkinton Invasive insects increasingly affect forested landscapes and have important ecological and economic impacts. My dissertation focuses on population dynamics of Winter moth (Operophtera brumata L.), an invasive pest in the northeastern United States. Native to Europe, this is the species’ fourth accidental introduction to North America. The Elkinton lab established the biological control agent Cyzenis albicans across the range of winter moth in the northeastern U.S. Prior research indicates that C. albicans’ ability to control winter moth likely depends on additional mortality from native natural enemies. My dissertation research evaluates the identity and role of natural enemies already present in North America (predators, parasitoids, and pathogens) on winter moth, and their interactions with mortality from C. albicans. I found that in earlier years of the current North American introduction, predator communities were saturated due to the abundance of pupae to consume; however, as Winter moth densities decreased to levels comparable to its native range (presumably due to mortality added to the system by C. albicans) pupal predation’s role on the population dynamics has changed; pupal predation is now density dependent and helps stabilize the vi Winter moth populations. Furthermore, I detected parasitism on winter moth pupae by an ichenumonid wasp (Pimpla spp.), which causes additional mortality on winter moth pupae and rarely kills C. albicans puparia. While rates of mortality on winter moth from this parasitoid are lower than those from predation, parasitism is also density dependent and has a stabilizing effect on winter moth populations. Lastly, my research shows that mortality in larval and pupal stages is lower on winter moth than on the native congener, Bruce spanworm, Operophtera bruceata Hulst. Cadavers from both species had low rates of infection from nucleopolyhedroviruses. Each host had its own virus species and there Were no cross-infectious betWeen the tWo. Microsporidia were detected in Bruce spanworm, but not in winter moth. I conclude that our biological control efforts have reduced winter moth populations to non-pest levels and I expect native natural enemies, along with C. albicans, will regulate population densities indefinitely. vii TABLE OF CONTENTS Page ACKNOWLEDGMENTS ...................................................................................................v ABSTRACT ....................................................................................................................... vi LIST OF TABLES ........................................................................................................... xiii LIST OF FIGURES ......................................................................................................... xiv CHAPTER 1. THE PHYLOGENETIC RELATIONSHIP AND CROSS-INFECTION OF NUCLEOPOLYHEDROVIRUSES BETWEEN THE INVASIVE WINTER MOTH (OPEROPHTERA BRUMATA) AND ITS NATIVE CONGENER, BRUCE SPANWORM (O. BRUCEATA) ..........................................................................................1 1.1 Abstract ..............................................................................................................1 1.2 Introduction ........................................................................................................2 1.3 Methods..............................................................................................................6 1.3.1 Collecting larvae and rearing ..............................................................6 1.3.2 DNA amplification and sequencing ....................................................8 1.3.3 Polyhedrin and p74 gene comparison ...............................................10 1.3.4 Cross infection trials .....................................................................................11 1.4 Results ..............................................................................................................12 1.4.1 Polyhedrin and p74 gene phylogenetic comparisons ........................12 1.4.2 Cross infection trials .........................................................................13 1.5 Discussion ........................................................................................................18 2. IDENTIFICATION AND IMPACT OF HYPERPARASITOIDS AND PREDATORS AFFECTING CYZENIS ALBICANS (TACHINIDAE), A RECENTLY INTRODUCED BIOLOGICAL CONTROL AGENT OF WINTER MOTH (OPEROPHTERA BRUMATA L.) IN THE NORTHEASTERN U.S.A. ..........................22 2.1 Abstract ............................................................................................................22 2.2 Introduction ......................................................................................................23 2.3 Methods............................................................................................................26 2.3.1 Deployment of sentinel puparia ........................................................26 viii 2.3.2 Examination and dissection of puparia .............................................28 2.3.3 Mortality estimate .............................................................................29 2.3.4 Statistical analysis .............................................................................31