On-farm evaluation of swede midge (Diptera: Cecidomyiidae) susceptibility among popular kale varieties.

Abstract

The swede midge, Contarinia nasturtii Kieffer (Diptera:Cecidomyiidae), is a gall-forming insect pest that targets cruciferous plants. Since its introduction to North America in the early 2000s, the midge has expanded its range to include farming regions in Quebec and the Northeastern USA. In this study, we evaluated the susceptibility of 4 popular kale varieties-Green Curly-(Vates), Red Russian, Red Curly (RedBor), and Lacinato/Tuscan-to swede midge infestation in on-farm trials conducted over consecutive years. Our results indicate substantial variability in susceptibility among varieties, with Red Russian kale consistently exhibiting the highest damage incidence across both years. These findings provide valuable insights for developing effective integrated pest management (IPM) strategies tailored to organic and small-scale vegetable farming contexts, emphasizing the role of crop genetic resources in pest mitigation and sustainable agriculture. In addition, this study highlights the potential of non-chemical approaches for managing swede midge, leading to a more diverse and adaptable IPM toolbox for growers.