2nd Place: Scent-sational snares: Optimizing and evaluating pheromone-baited traps as tools for monitoring Contarinia brassicola on the Canadian prairies

The larvae of gall midges (Diptera: Cecidomyiidae) secrete compounds that can result in the growth of abnormal structures on their plant host. These structures, known as galls, help to protect and nourish the larvae as they develop. Many gall midges are devastating pests of agricultural crops and are challenging to detect and manage. Contarinia brassicola Sinclair is a recently discovered gall midge on the Canadian prairies. Larvae of C. brassicola form galls in flower buds of canola (Brassica napus), preventing pod formation and seed set. The development of an optimized synthetic sex pheromone blend attractive to C. brassicola males has facilitated the use of pheromone-baited traps as promising tools for monitoring population density and activity of male midges. To optimize the design of pheromone-baited traps and to investigate the relationship between male midge population density and subsequent larval damage, experiments were conducted in 2021 and 2022 in Alberta, Canada. Analysis on the relationship between trap capture and larval damage is still ongoing, but we found that both trap design and placement have a significant effect on midge capture rate with pheromone-baited Jackson traps set 10 to 50 cm above the ground at the edge of canola fields capturing significantly more midges than their counterparts. Insights from these investigations will help refine the tools used to monitor and study C. brassicola and better inform future management decisions.