Entomology Extension Educator University of Vermont Burlington, Vermont
The swede midge, Contarinia nasturtii Kieffer, is a gall-forming insect pest species of cruciferous plants. Historically distributed throughout Europe and southwestern Asia, the first documented reports of swede midge infestations within North America occurred during the early 2000s in Ontario, Canada (Chen et al., 2011; Hallett, 2007). Following its arrival, the midge is expanding its distribution eastward and southward, and currently inhabits farming regions within Quebec (CA), New York, and much of Northern New England (Chen et al., 2011). As an oligophagous pest of the Brassicaceae family of cultivated crops (Chen et al., 2011; Hallett, 2007) the midge is particularly problematic in cooler temperate regions where brassica crop production constitutes a valuable portion of the local fresh vegetable market. While conventional management practices (e.g. chemical pesticides) for the control of the swede midge are currently in use for many large northeastern growers, organic methods are few and typically exhibit poor efficacy (Hallett & Sears, 2013). To assess the potential development of a trap cropping system for swede midge in kale and/or other brassica crops, we performed replicated field trials to determine the variability in swede midge susceptibility and tolerance among several kale varieties. Red Russian kale exhibited significantly higher levels of damage when compared to other kale varieties during 2021 field trials. The potential reasons for this difference and the utility of Red Russian kale as a potential trap or "attract and kill" will be discussed, along with a brief synopsis of the 2022 field trial results.