APPLYING THE INTRA-TREE DISTRIBUTION AND FORAGING BEHAVIOUR OF THE ELM SPANWORM, ENNOMOS SUBSIGNARIA, ON MATURE SYCAMORE MAPLE TO MANAGEMENT PRACTICES DURING AN URBAN OUTBREAK by Heidi Rosanna Clarice Fry Bachelor of Science (Honours), Biology, Memorial University of Newfoundland (2005) A Thesis Submitted in Partial Fulfillment of the Requirements for the Degree of Master of Science In the Graduate Academic Unit of Biology Supervisor(s): Dan T. Quiring, PhD, Biology, UNB Krista L. Ryall, PhD, Forestry and Environmental Management, UNB Examining Board: Dr. Les Cwynar, PhD, Biology, UNB, Chair Dr. Graham Forbes, PhD, Biology, UNB Dr. Graham Thurston, PhD, Forestry and Environmental Management, UNB This thesis is accepted by the Dean of Graduate Studies THE UNIVERSITY OF NEW BRUNSWICK October, 2007 © Heidi R. C. Fry, 2007 Library and Archives Bibliotheque et 1*1 Canada Archives Canada Published Heritage Direction du Branch Patrimoine de I'edition 395 Wellington Street 395, rue Wellington Ottawa ON K1A 0N4 Ottawa ON K1A0N4 Canada Canada Your file Votre reference ISBN: 978-0-494-63767-8 Our file Notre reference ISBN: 978-0-494-63767-8 NOTICE: AVIS: The author has granted a non­ L'auteur a accorde une licence non exclusive exclusive license allowing Library and permettant a la Bibliotheque et Archives Archives Canada to reproduce, Canada de reproduire, publier, archiver, publish, archive, preserve, conserve, sauvegarder, conserver, transmettre au public communicate to the public by par telecommunication ou par Nnternet, preter, telecommunication or on the Internet, distribuer et vendre des theses partout dans le loan, distribute and sell theses monde, a des fins commerciales ou autres, sur worldwide, for commercial or non­ support microforme, papier, electronique et/ou commercial purposes, in microform, autres formats. paper, electronic and/or any other formats. The author retains copyright L'auteur conserve la propriete du droit d'auteur ownership and moral rights in this et des droits moraux qui protege cette these. Ni thesis. Neither the thesis nor la these ni des extraits substantiels de celle-ci substantial extracts from it may be ne doivent etre imprimes ou autrement printed or otherwise reproduced reproduits sans son autorisation. without the author's permission. In compliance with the Canadian Conformement a la loi canadienne sur la Privacy Act some supporting forms protection de la vie privee, quelques may have been removed from this formulaires secondaires ont ete enleves de thesis. cette these. While these forms may be included Bien que ces formulaires aient inclus dans in the document page count, their la pagination, il n'y aura aucun contenu removal does not represent any loss manquant. of content from the thesis. 1+1 Canada Dedicated to my parents, Mollie and Frank, and my sister, Sarah 11 ABSTRACT Ennomos subsignaria laid most eggs on the lower bole of mature sycamore maple. Egg hatch was synchronized with the availability of the most suitable leaves for insect development on proximal branches of the lower crown, the location where most larvae initiated feeding. Intra-tree larval and pupal distribution was not influenced by variable natural enemy activity or foliage quality within the crown. This is the first evidence of a restricted phenologjcal window of foliage suitability for an early-season caterpillar feeding on leaves that have expanded past bud scales. Monitoring egg masses on the lower bole and early-instars in the lower crown provided a reliable forecast of end of season defoliation and therefore can assist pest managers when deciding to use (or not to use) suppression methods. Two-thirds of the manufacturer recommended dose of bole-implanted acephate (AceCap® 97) significantly reduced E. subsignaria density and defoliation during the treatment year. Key words: Ennomos subsignaria, elm spanworm, sycamore maple, intra-tree variation, phenology, egg hatch, foraging behaviour, pest management, acephate in PREFACE The three main chapters presented in this thesis are independent but related manuscripts that have been prepared for publication in Ecological Entomology (Chapter 2), Forest Ecology and Management (Chapter 3) and the Journal of Economic Entomology (Chapter 4). The authorship of all publications will be: Heidi R. C. Fry1, Dan T. Quiring1,2, Krista L. Ryall2'3 and Peggy L. Dixon2'4 'Population Ecology Group, Department of Biology, University of New Brunswick, Fredericton, New Brunswick, Canada, E3B 5P7 Population Ecology Group, Faculty of Forestry and Environmental Management, University of New Brunswick, Fredericton, New Brunswick, Canada, E3B 5P7 3Natural Resources Canada, Canadian Forest Service - Atlantic Forestry Centre, P.O. Box 960, Corner Brook, Newfoundland and Labrador, Canada, A2H 6J3 4Agriculture and Agri-Food Canada, Atlantic Cool Climate Crop Research Centre, P.O. Box 39088, St. John's, Newfoundland and Labrador, Canada, A1E 5Y7 During the development of these manuscripts, I was primarily responsible for the design and organization of experiments, the preparation and presentation of the initial research proposal, collecting and analyzing data, and writing the manuscripts. Dan Quiring was involved in all aspects of this research. Many of the ideas presented in this thesis reflect the essential advice and guidance given by Dan. Krista Ryall provided important feedback on experimental design as well as valuable information during the iv development of these manuscripts. Peggy Dixon provided logistical support throughout the study, good suggestions on sampling and rearing, and provided valuable comments and suggestions during the preparation of these manuscripts. v ACKNOWLEDGMENTS I sincerely thank my supervisor, Dr. Dan Quiring, for the guidance and encouragement that he provided starting from our first conversation. Dan's excellent academic feedback coupled with his friendly nature made my graduate studies at the University of New Brunswick very enjoyable. Also, my co-supervisor, Dr. Krista Ryall, provided me with important comments regarding the design of experiments and content of manuscripts. Thanks to my committee member Dr. Peggy Dixon, who provided valuable comments on manuscripts, laboratory space during my field seasons and helped with fieldwork. I also thank my committee member Dr. Yvan Pelletier who provided important feedback during committee meetings and on manuscripts, as well as committee member Dr. Tillmann Benfey, who also provided important comments on manuscripts. I thank Dr. Mike Duffy who provided me a teaching assistantship position as well as Linda Allen, Rose Comeau and Bonny Morrison, who were all very helpful during my graduate studies. I thank my lab mates, including Drew Carleton, Leah Flaherty, Roger Graves, Rob Johns, Jonathan Leggo, Andrew Morrison, Lauren Pinault and Kate Van Rooyen, who were always supportive and provided feedback on presentations. Thanks to everyone who helped me in the field and processing samples in the lab but I especially thank Ryan Pugh for his dedication and humour. During my field seasons it was a pleasure to work out of the Atlantic Cool Climate Crop Research Centre in St. John's where the staff was always friendly and helpful. In particular I thank members of the Dixon entomology lab, including Robyn Auld, Janet Coombes, Nancy vi Hudson and Carolyn Parsons, for their support and friendship. I also thank Dave Evans and the field crew working for the Department of Parks and Services in St. John's for access to my field sites. I thank the Canadian Forest Service, the University of New Brunswick and the Canadian Tree Fund for providing financial support during my graduate studies. This work would not have been completed without the continuous encouragement, support and understanding given by my parents, Frank and Mollie, and sister, Sarah. I was fortunate to be able to carry out my research in my hometown, St. John's, where local enthusiasm for elm spanworm research made my field seasons even more enjoyable. vn TABLE OF CONTENTS ABSTRACT iii PREFACE iv ACKNOWLEDGEMENTS vi LIST OF TABLES x LIST OF FIGURES xi CHAPTER 1: GENERAL INTRODUCTION 1 References 6 CHAPTER 2: INFLUENCE OF INTRA-TREE VARIATION IN PHENOLOGY AND OVIPOSITION SITE ON THE DISTRIBUTION AND PERFORMANCE OF ENNOMOS SUBSIGNARIA ON MATURE SYCAMORE MAPLE 13 Abstract 13 Introduction 14 Methods 17 Study insect and plant 17 Study sites 17 Intra-tree distribution, parasitism and herbivory 18 Description of sycamore maple bud and leaf development 21 Effect of host phenological stage on insect performance 21 Synchrony between budburst and egg hatch 23 Statistical analyses 24 Results 25 Intra-tree distribution, parasitism and herbivory. 25 Effect of host phenological stage on insect performance 27 Synchrony between budburst and egg hatch 28 Discussion 29 Acknowledgements 33 References 34 CHAPTER 3: RELATIONSHIPS BETWEEN ELM SPANWORM, ENNOMOS SUBSIGNARIA, DENSITY AND DEFOLIATION ON MATURE SYCAMORE MAPLE IN AN URBAN ENVIRONMENT 48 Abstract 48 Introduction 49 Methods 52 Description of study insect 52 Study sites 52 Estimating defoliation 53 Predictive density-defoliation relationships 53 Statistical analyses 56 Results 56 Estimating defoliation 56 Predictive density-defoliation relationships 57 Vlll Discussion 57 Acknowledgements 60 References 60 CHAPTER 4: SUPPRESSION OF ENNOMOS SUBSIGNARIA (LEPIDOPTERA : GEOMETRIDAE) ON ACER PSEUDOPLATANUS (ACERACEAE) IN AN URBAN FOREST USING BOLE-IMPLANTED ACEPHATE 69 Abstract 69 Introduction 70 Materials and Methods 71 Study insect 71 Study site