Soybean Gall Midge Adult Emergence Beginning in Iowa

June 17, 2021
ICM News

This week, the first adult soybean gall midges (Photo 1) were collected in Iowa and Minnesota. Thanks to Lauren Schwarck (Corteva Agriscience) for monitoring several emergence traps this year. The positive detections were located in Buena Vista County, an area with persistent soybean gall midge populations since at least 2017.


Photo 1. Adult soybean gall midge.

The adults have been steadily emerging from Nebraska for three weeks. Approximately two weeks after first emergence, plant injury was noted at some Nebraska collection sites. Based on their emergence timing, we would expect to see feeding injury to start appearing near previously infested fields next week.

Soybean gall midge is a new soybean pest that is only known to occur in 114 counties in 5 states (Figure 1): Nebraska, Iowa, Minnesota, South Dakota, and Missouri. Currently, 31 counties in western Iowa have positive detections as of 2020. The larvae (maggots) of gall midges feed inside the stem near the base of the soil. Eventually, infested plants may become brittle and break off at the site of feeding. Entire plants may die as a result of feeding, causing significant yield losses for a field. Typically, infestations begin at the field edge, where farmers will notice wilted or dead plants, then advance toward the interior.


Figure 1. Locations in Nebraska, Iowa, Minnesota, South Dakota, and Missouri where soybean gall midge has been identified. Map by Justin McMechan (UNL). 

Iowa has several trapping locations this year and supports a regional trapping network in four states. We will continue to provide updates on adult emergence throughout the summer. To stay updated on state and regional midge activity, we encourage you to subscribe to the Alert Network: https://soybeangallmidge.org/sign-up-for-network-updates.

Learn how to scout for soybean gall midge larvae in these videos: https://soybeangallmidge.org/scouting-for-soybean-gall-midge.

Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Integrated Crop Management News, and Iowa State University Extension and Outreach. If this article is to be used in any other manner, permission from the author is required. This article was originally published on June 17, 2021. The information contained within may not be the most current and accurate depending on when it is accessed.

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Erin Hodgson Professor

Dr. Erin Hodgson started working in the Department of Entomology at Iowa State University in 2009. She is an associate professor with extension and research responsibilities in corn and soybeans. She has a general background in integrated pest management (IPM) for field crops. Dr. Hodgson's curre...

Ashley Dean Education Extension Specialist I

Ashley is an education extension specialist for field crop entomology at Iowa State University. She coordinates the Iowa Moth Trapping Network, develops educational resources for field crop pests in Iowa, and aids in the research efforts of the