Distribution, Abundance, and Biological Control Potential of Synopeas myles, a Parasitoid of the Swede Midge
The swede midge, Contarinia nasturtii Kieffer (Diptera: Cecidomyiidae), is a major invasive pest of canola and other plants in the Brassicaceae family. Current pest management practices fail to ensure adequate crop protection. The parasitoid Synopeas myles Walker (Hymenoptera: Platygastridae), an adventively introduced natural enemy of C. nasturtii, was discovered in Ontario in 2016. The overall goal of this project was to quantify the potential of S. myles as a biological control candidate to use in an integrated pest management approach for C. nasturtii in Ontario, as well as to assess possible biological control practices to promote this parasitoid. Synopeas myles was found to be widespread across canola growing regions of Ontario, with parasitism rates close to 6% on average. Floral supplements showed promising potential to increase parasitoid longevity, but not fecundity. Parasitism rates were positively associated with percent managed surroundings and presence of wild flowers near field edges, and negatively associated with soil silt content and C. nasturtii population density.