Help inform Minnesota Japanese beetle research by filling out a short survey

Author: Marissa Schuh

While the peak of Japanese beetle activity was earlier this month, beetles are still out and feeding on raspberries, grapes, basil, and more. In many places where we see the beetles, we often see winsome fly -- a parasitoid fly species that kills adult Japanese beetles. Female flies lay their eggs on the pronotum (the middle, shoulder-like area) of Japanese beetles, a baby fly hatches, and then burrows into the Japanese beetle. This kills the beetle over the course of a week. While these flies aren't going to give us 100% control of Japanese beetle, natural enemies like this are a part of living long term with Japanese beetle.

The white spot on the green pronotum of this Japanese beetle is a Winsome fly egg. Photo: Whitney Cranshaw, Colorado State University, Bugwood.org

The University of Minnesota is developing a research proposal focused on Japanese beetle management and the winsome fly. The proposed research will examine whether insecticide products or application timing can be adjusted to reduce harm to winsome fly while maintaining practical Japanese beetle control.

We want to make sure the research will be helpful for Minnesota fruit and vegetable growers. Help us make sure the research captures your growing system and management practices by filling out our survey, Japanese Beetle Management Practices and Decision-Making in Minnesota. The survey is anonymous, works on mobile, and should take 3-4 minutes.