The University of Maine DigitalCommons@UMaine Electronic Theses and Dissertations Fogler Library Summer 8-2015 The Relationship Between the Winter Moth (Operophtera brumata) and Its Host Plants in Coastal Maine Kaitlyn M. O'Donnell University of Maine - Main, [email protected] Follow this and additional works at: https://digitalcommons.library.umaine.edu/etd Part of the Biology Commons, and the Other Forestry and Forest Sciences Commons Recommended Citation O'Donnell, Kaitlyn M., "The Relationship Between the Winter Moth (Operophtera brumata) and Its Host Plants in Coastal Maine" (2015). Electronic Theses and Dissertations. 2338. https://digitalcommons.library.umaine.edu/etd/2338 This Open-Access Thesis is brought to you for free and open access by DigitalCommons@UMaine. It has been accepted for inclusion in Electronic Theses and Dissertations by an authorized administrator of DigitalCommons@UMaine. For more information, please contact [email protected]. THE RELATIONSHIP BETWEEN THE WINTER MOTH (OPEROPTHERA BRUMATA) AND ITS HOST PLANTS IN COASTAL MAINE By Kaitlyn O’Donnell B.S. Saint Michael’s College, 2011 A THESIS Submitted in Partial Fulfillment of the Requirements for the Degree of Master of Science (in Entomology) The Graduate School The University of Maine August 2015 Advisory Committee: Eleanor Groden, Professor of Entomology, School of Biology and Ecology, Advisor Francis Drummond, Professor of Insect Ecology and Wild Blueberry Pest Management Specialist, School of Biology and Ecology and the University of Maine Cooperative Extension Joseph Elkinton, Professor of Environmental Conservation, University of Massachusetts Charlene Donahue, Forest Entomologist, Maine Forest Service THESIS ACCEPTANCE STATEMENT On behalf of the Graduate Committee for Kaitlyn O’Donnell I affirm that this manuscript is the final and accepted thesis. Signatures of all committee members are on file with the Graduate School at the University of Maine, 42 Stodder Hall, Orono, Maine. Dr. Eleanor Groden, Professor of Entomology Date ii © 2015 Kaitlyn O’Donnell All Rights Reserved iii LIBRARY RIGHTS STATEMENT In presenting this thesis in partial fulfillment of the requirements for an advanced degree at the University of Maine, I agree that the Library shall make it freely available for inspection. I further agree that permission for “fair use” copying of this thesis for scholarly purposes may be granted by the Librarian. It is understood that any copying or publication of this thesis for financial gain shall not be allowed without my written permission. Signature: Date: THE RELATIONSHIP BETWEEN THE WINTER MOTH (OPEROPTHERA BRUMATA) AND ITS HOST PLANTS IN COASTAL MAINE By Kaitlyn O’Donnell Thesis Advisor: Dr. Eleanor Groden An Abstract of the Thesis Presented in Partial Fulfillment of the Requirements for the Degree of Master of Science (in Entomology) August 2015 This project examines the recent outbreak of the invasive winter moth (Operophtera brumata) in mid-coast Maine. The winter moth was introduced into New England in the late 1990’s and low densities of winter moth were detected with pheromone traps throughout the Maine coast in 2006. Severe defoliation occurred for the first time in Maine in the spring of 2012 in Harpswell and Vinalhaven, ME. This pest attacks an extremely broad range of host plants, including forest hardwood trees and agricultural crops such as highbush blueberry and apple. The objectives of this study are to examine the differential development and survival of the winter moth on common hardwood forest trees as well as important agricultural crops, to determine the insect phenology in relation to host plants throughout the year in Maine, to monitor the relative population densities on different host plants, and to survey Maine winter moth for pathogens already present in the population. We found that larval survival and densities are significantly higher on red oak and apple trees and lowest on pin cherry. Larval survival is significantly higher when vi egg hatch is closely synchronized with host plant bud burst. Lastly, using molecular markers, we inferred the presence of winter moth nucleopolyhedrovirus in larvae collected from seven different host plants, including wild lowbush blueberry. Larvae were observed feeding on wild lowbush blueberry, a new host for this species. While larval survival and densities are lower on lowbush blueberry than on oak and apple, they readily feed on and cause severe damage to wild blueberry when populations are at outbreak levels. Through studying the biology of this insect, we are able to determine the factors that are closely linked to its survival in the hopes of developing methods of control before seeing irreparable damage to Maine’s forests and agriculture. ACKNOWLEDGMENTS I would like to thank my advisor, Dr. Eleanor Groden, for all of her guidance throughout my graduate career at the University of Maine. I would also like to thank my committee, Dr. Francis Drummond, Charlene Donahue, and Dr. Joseph Elkinton, for being so supportive and helpful with all aspects of my research. I have learned a great deal through this project and have really enjoyed my experience working with winter moth. I am also grateful for my funding sources, the Maine Agriculture and Forest Experiment Station, the Maine Agricultural Center, and the University of Maine Graduate School and Graduate Student Government. I thank Sharon Whitney, Marlene and Freddie Ward, and the residents of Harpswell for welcoming me into their homes, for their encouragement, and for showing so much interest in my research. I also thank Hillary Morin, who helped me with field work throughout my Master’s and did a wonderful job studying winter moth for her Honor’s thesis. I would like to thank Hannah Broadley and Dr. John Burand from the University of Massachusetts for teaching me the procedures for molecular NPV detection. I would like to thank my fellow laboratory mates Jen Lund, Elissa Ballman, and Tamara Levitsky for all of their help with field and laboratory work and moral support along the way. Lastly, I would like to thank my family and friends for always being there and believing in me. iv TABLE OF CONTENTS ACKNOWLEDGMENTS……………………………………………………………………………………..….iv LIST OF TABLES..……………………...…………………………………………………………………….…viii LIST OF FIGURES…………………………………………………………………………………………………ix CHAPTER ONE: BIOLOGY AND ECOLOGY OF THE WINTER MOTH…………………………1 Winter Moth Invasion……………………………………………………………………………………..1 Winter Moth Biology and Life Cycle…………………………………………………………………2 Potential Control…………………………………………………………………………………………….4 Damage to Host Plants……………………………………………………………………………………6 Host Plant Effects……………………………………………………………………………………………8 CHAPTER TWO: HOST PLANT EFFECTS ON WINTER MOTH LARVAL DEVELOPMENT AND SURVIVAL……………………………..………………………………………….11 Abstract………………………………………………………………………………………………………..11 Introduction…………………………………………………………………………………………………11 Methods……………………………………………………………………………………………………….15 Host Plant Phenology…………………………………………………………………………16 Larval Density……………………………………………………………………………………17 Statistical Analysis…………………………………………………………………..17 Larval Development…………………………………………………………………………...18 Statistical Analysis…………………………………………………………………..18 Survival……………………………………………………………………………………………..19 Laboratory Rearing Experiment……………………………………………….19 Statistical Analysis………………………………………………………..19 v Field Sleeve Cage Experiment…………………………………………………..20 Statistical Analysis………………………………………………………..22 NPV Incidence…………………………………………………………………………23 Statistical Analysis………………………………………………………..24 Results…………………………………………………………………………………………………………24 Host Plant Phenology…………………………………………………………………………24 Larval Density……………………………………………………………………………………25 Larval Development…………………………………………………………………………...30 Survival……………………………………………………………………………………………..32 Laboratory Rearing Experiment……………………………………………….32 Field Sleeve Cage Experiment…………………………………………………..36 NPV Incidence…………………………………………………………………………38 Discussion…………………………………………………………………………………………………….40 CHAPTER THREE: POPULATION TRENDS OF ADULT WINTER MOTH (OPEROPHTERA BRUMATA) OVER TWO YEARS IN HARPSWELL, MAINE…..………….48 Abstract………………………………………………………………………………………………………..48 Introduction…………………………………………………………………………………………………48 Methods……………………………………………………………………………………………………….49 Study Sites…………………………………………………………………………………………49 Male Relative Density…………………………………………………………………………50 Female Relative Density…………………………………………………………………......50 vi Results…………………………………………………………………………………………………………51 Male Relative Density…………………………………………………………………………51 Female Relative Density……………………………………………………………………..54 Discussion…………………………………………………………………………………………………….55 CHAPTER FOUR: WINTER MOTH – SPRING DEFOLIATOR OF WILD BLUEBERRY………………………………………………………………………………………………………58 Introduction…………………………………………………………………………………………………58 Description…………………………………………………………………………………………………..58 Adults………………………………………………………………………………………………..58 Eggs…………………………………………………………………………………………………..60 Larvae……………………………………………………………………………………………….61 Pupae………………………………………………………………………………………………...62 Life Cycle……………………………………………………………………………………………………62 Host Plant Damage………………………………………………………………………………………..64 Control and Management………………………………………………………………………………64 LITERATURE CITED…………………………………………………………………………………………...66 APPENDIX A: ADULT FEMALE PREDATION………....……………………………………..............73 APPENDIX B: PUPAL SURVIVAL IN POTTING MIX……………………………..…………...........77 BIOGRAPHY OF THE AUTHOR…………………………………………………………………………….79 vii LIST OF TABLES Table 2.1. Mean number of winter moth larvae and host