Assessment of conservation biological control tactics to support the parasitism success of Synopeas myles (Hymenoptera: Platygastridae)

Conservation biological control tactics were evaluated for their impact on the survival and parasitism success of Synopeas myles Walker (Hymenoptera: Platygastridae), a parasitoid of swede midge, Contarinia nasturtii (Kieffer) (Diptera: Cecidomyiidae). Insecticide toxicity to S. myles was evaluated, and Matador® was harmful to adults via direct and residual contact, while Movento® and Coragen® were harmless (Sterk et al. 1999). Sweet alyssum was evaluated as a supplemental plant for supporting S. myles, and S. myles parasitized more C. nasturtii when provided with flowering sweet alyssum than without. Contarinia nasturtii females did not oviposit on, and larvae did not develop on, sweet alyssum plants, and therefore, sweet alyssum is unlikely to be a suitable host plant for C. nasturtii. Flowering sweet alyssum did not deter C. nasturtii from ovipositing on canola plants. This study found that insecticide selection and supplemental plantings of sweet alyssum may help support S. myles populations in canola.