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Impact of Crop Phenology and Infestation Timing on Damage and Pest Management of the Swede Midge, Contarinia Nasturtii (Diptera: Cecidomyiidae), in Canola

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Impact of Crop Phenology and Infestation Timing on Damage and Pest Management of the Swede Midge, Contarinia Nasturtii (Diptera: Cecidomyiidae), in Canola Impact of Crop Phenology and Infestation Timing on Damage and Pest Management of the Swede Midge, Contarinia nasturtii (Diptera: Cecidomyiidae), in Canola by Jonathon Williams A Thesis presented to The University of Guelph In partial fulfilment of requirements for the degree of Master of Science in Environmental Sciences Guelph, Ontario, Canada © Jonathon Williams, April, 2015 ABSTRACT IMPACT OF CROP PHENOLOGY AND INFESTATION TIMING ON DAMAGE AND PEST MANAGEMENT OF THE SWEDE MIDGE, CONTARINIA NASTURTII (DIPTERA: CECIDOMYIIDAE) IN CANOLA Jonathon Williams Advisor: University of Guelph, 2015 Professor R.H. Hallett The relationship between canola, Brassica napus L., crop phenology and susceptibility to the swede midge, Contarinia nasturtii (Kieffer) was investigated to improve insecticide application timing recommendations and management of this invasive pest. Insecticide applications were more critical at vegetative and early bud stages than during secondary bud formation in studies of insecticide application timing based on growth stage conducted in growers’ fields over two years. However, treatment timing effects on swede midge damage and yield varied depending on field site. Laboratory studies were conducted to elucidate relationships between swede midge oviposition preference and density, crop stage, and damage and yield effects. A significant negative relationship was observed between swede midge density and canola seed yield and pod number, as well as the potential for damage compensation by secondary raceme growth. These results may contribute to the development of swede midge pheromone action thresholds and understanding the compensatory ability of canola. ACKNOWLEDGEMENTS I would like to thank my advisor, Dr. Rebecca Hallett for her guidance and encouragement throughout this project and for instilling both confidence and knowledge that I will use well into the future. I would also like to thank Dr. Hugh Earl for advising me and for his invaluable insight into this project. Thank you to Laxhman Ramsahoi for sharing his protocol for growing great canola in the greenhouse and to Braden Evans for helping to set up and maintain my swede midge colony and for welcoming me to Biocontrol. Thank you to our technician Jamie Heal for his assistance in the field. I cannot thank our many undergraduate assistants enough for their unwavering energy and enthusiasm in the face of unpredictable weather, long drives and longer field days. Thank you to Caitlyn Schwenker, Taylor Laplante, Karen Ball, Christine Weston, Cassie Russell, and Graham Davy. I would like to thank Brian Hall for his vital assistance in all stages of my field experiments and for offering his considerable canola expertise to this project. Thanks to Carrie James for assisting with organization and for helping to find willing cooperators. I would like to thank canola growers John Kidd, Don Curry, Harry Biermans, Ray McCabe, Jonathan Sammons and Holmes Agro for allowing us access to your fields, always assisting when we called upon you and for your contribution to applied agricultural research. Thank you to friends and colleagues Angela, Andrew, Justin, Zach and Kristin. Thank you to my parents Chris and Judy Williams for always loving, supporting and encouraging me in everything that I do and for trusting me to make iii the right decisions. Thank you to my brothers and my family for always believing in me and for patiently listening to me talk about insects. Nicole Daoust, thank you for your help in the field and for always standing by my side. You are my biggest inspiration and I wouldn’t be where I am today without your support and love every single day. I am also thankful for the financial support provided by the Ontario Canola Growers Association, Canola Council of Canada, Eastern Canada Oilseeds Development Alliance and the OMAFRA-University of Guelph Sustainable Production Program. iv TABLE OF CONTENTS ACKNOWLEDGEMENTS ...................................................................................... iii TABLE OF CONTENTS .......................................................................................... v LIST OF TABLES .................................................................................................... vii LIST OF FIGURES .................................................................................................. viii CHAPTER 1. Introduction 1.1. Swede midge, Contarinia nasturtii ........................................................ 2 1.1.1. Description & life cycle ........................................................ 2 1.1.2. Host plants ............................................................................ 4 1.1.3. Geographic distribution ........................................................ 5 1.1.4. Swede midge as a pest in North America ............................. 6 1.2. Canola 1.2.1. Canola as a crop in Canada ................................................... 9 1.2.2. Growth stages ........................................................................ 10 1.3. Pest management in canola 1.3.1. Pests of canola in Ontario ..................................................... 12 1.3.2. Swede midge as a pest of canola ........................................... 15 1.3.3. Rating swede midge damage on canola ................................ 20 1.4. Summary & objectives ........................................................................... 22 v CHAPTER 2. Insecticide application timing for control of swede midge in spring canola 2.1 Introduction ............................................................................................. 24 2.2 Materials & Methods .............................................................................. 27 2.3 Results ..................................................................................................... 34 2.4 Discussion ............................................................................................... 54 CHAPTER 3. Swede midge oviposition, larval distribution & damage on canola 3.1 Introduction ............................................................................................. 62 3.2 Materials & Methods .............................................................................. 64 3.3 Results ..................................................................................................... 70 3.4 Discussion ............................................................................................... 80 CHAPTER 4. General discussion ............................................................................. 84 REFERENCES CITED ............................................................................................. 90 vi LIST OF TABLES Table 2.1 Field coordinates, canola cultivar, seed treatment and seeding rate of grower field sites for 2013 and 2014 field trials in Ontario ........... 28 Table 2.2 Insecticide treatment and application timing for 2013 and 2014 grower field studies ........................................................................... 30 Table 2.3 Damage rating scheme for Contarinia nasturtii damage on canola .. 32 Table 2.4 Canola seed yield following chlorantraniliprole treatment applications in 2013 grower field study ............................................ 39 Table 2.5 Canola seed yield following chlorantraniliprole or λ-cyhalothrin treatment applications in 2014 grower field study ............................ 46 Table 3.1 Contarinia nasturtii oviposition per plant and percent oviposition per plant on stage 3.1 canola, 7 days following infestation .............. 71 Table 3.2 Contarinia nasturtii oviposition per plant, proportional oviposition and percent oviposition per plant on four growth stages of canola 72 hours following infestation in a choice experiment ..................... 77 Table 3.3 Contarinia nasturtii oviposition per plant, oviposition per female and percent oviposition per plant on four growth stages of canola 72 hours following infestation in a no-choice experiment ................ 79 vii LIST OF FIGURES Figure 2.1 Consolidated and primary raceme Contarinia nasturtii damage ratings of canola following chlorantraniliprole applications at Chesley, Owen Sound, Honeywood, and Orangeville, ON grower field sites in 2013 ............................................................................... 35 Figure 2.2 Secondary raceme Contarinia nasturtii damage ratings of canola following chlorantraniliprole applications at Chesley, Owen Sound, Honeywood, and Orangeville, ON grower field sites in 2013 ........... 36 Figure 2.3 Percent Contarinia nasturtii damage ratings of canola following chlorantraniliprole applications at Chesley, Owen Sound, Honeywood, and Orangeville, ON grower field sites in 2013 ........... 37 Figure 2.4 Canola yield as a proportion of the control following chlorantraniliprole applications at Chesley, Owen Sound, Honeywood, and Orangeville, ON grower field sites in 2013 ........... 39 Figure 2.5 Consolidated and primary raceme Contarinia nasturtii damage ratings of canola following λ-cyhalothrin applications at Owen Sound, Shelburne, Feversham, and Mono, ON grower field sites in 2014 .................................................................................................... 40 Figure 2.6 Secondary and tertiary raceme Contarinia nasturtii damage ratings of canola following λ-cyhalothrin applications at Owen Sound, Shelburne, Feversham, and Mono, ON grower field sites in 2014 .... 43 Figure 2.7 Percent Contarinia nasturtii damage ratings of canola
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