Organic management of the invasive swede midge (Diptera: Cecidomyiidae) on Brassica vegetables: multiple dead ends necessitate novel approaches

Abstract

Abstract The distinctive biology and ecology of the invasive swede midge, Contarinia nasturtii Kieffer (Diptera: Cecidomyiidae), render organic management in North America particularly challenging, necessitating the search for novel out-of-the box approaches to control it. Native to Eurasia, this pest was first confirmed in North America in 2000 and has since spread to several states and provinces in the United States and Canada. As a galling midge, swede midge feeding causes distorted growth in Brassica (Brassicales: Brassicaceae) vegetables, resulting in major losses of marketable produce. While conventional growers typically use systemic insecticides for plant protection early in the season, equivalent approaches for organic production do not exist. The lack of effective organic management approaches for swede midge has resulted in devastating losses for heading Brassica vegetables, which are the most sensitive to midge feeding. Here, we review over 2 decades of research focused on developing organic approaches to manage swede midge. To encourage more rapid progress on swede midge management, we believe that it is important to review the widest array of work, including recent publications as well as our unpublished research. We conclude by highlighting the most promising strategies that should be utilized on farms and explored further for organic management of swede midge in vegetable crops.