Organic Management of Swede Midge

Abstract

Swede midge (Contarinia nasturtii) is a small (1/16” long) invasive fly that is a serious pest of Brassica (cruciferous) vegetable crops, including broccoli, cabbage, and kale. The insect was named for one of its hosts in Europe, the “swede,” a type of forage turnip. Management of swede midge is particularly challenging because of its small size, hidden feeding behavior, low damage threshold, and life cycle consisting of multiple overlapping generations during the growing season. Small-scale organic growers with insufficient space for crop rotation to break the swede midge life cycle are especially at risk for economic losses from this pest.