Pheromone trap monitoring reveals the continued absence of swede midge in the Northern Great Plains

The swede midge, Contarinia nasturtii (Kieffer) (Diptera: Cecidomyiidae), is invasive to North America, where it was first reported in Ontario, Canada. It is now established in eastern Canada and from eastern Minnesota in the Midwest to the northeastern seaboard of the United States of America. Swede midge is a serious pest of brassicaceous plants, including vegetable and oilseed crops. To ensure its early detection in the Northern Great Plains, a monitoring programme was established using pheromone traps located primarily along the edges of canola fields from North Dakota, United States of America, northwest to the Peace River region, in Alberta and British Columbia, Canada. In North Dakota, 117 trap sites were monitored between 2015 and 2021. In western Canada, monitoring occurred on a small scale from 2006 to 2011, and 521 trap sites were monitored from 2013 to 2021. Swede midge was not detected in canola grown in the Northern Great Plains between 2006 and 2021. Partners in North Dakota and western Canada intend to maintain the monitoring programme to support early detection of swede midge if it does continue to disperse northwestwards. The monitoring programme contributes to outreach activities and fosters farmer and agronomist participation in pest management (i.e., community science) in the Northern Great Plains.