Update on soybean gall midge

August 21, 2020 9:44 AM
Blog Post

The range of soybean gall midge has expanded in 2020. There are three new counties in Iowa (Osceola, Dickinson, and Calhoun) for a total of 29. So far, 108 total counties are confirmed in Iowa, Minnesota, Missouri, Nebraska, and South Dakota. Likely more counties have soybean gall midge but haven’t scouted yet.

Soybean gall midge distribution map.
Current soybean gall midge distribution (18 August 2020). 

Observations from Iowa agronomists, farmers, and myself this summer:

  • Fields that were infested in 2018/2019 were likely to be infested again. The spread to new fields has been slow.
  • The intensity of injured plants was about equal to or less than in previous growing seasons.
  • Infested plants are likely found along field edges, but are more scattered. As a result, visual signs of injury and plant death were more difficult to assess from a distance.
  • Part the soybean canopy to look for wilting, discolored or dead plants; use a knife to peel back the outer layers.
  • Soybean with fungal pathogens can be easily confused for soybean gall midge.
  • Older larvae will be bright orange and the soybean tissue around the feeding sites will be dark brown.

Visit www.soybeangallmidge.org for real-time updates on pest activity.


Erin Hodgson Professor

Dr. Erin Hodgson started working in the Department of Entomology, now the Department of Plant Pathology, Entomology, and Microbiology, at Iowa State University in 2009. She is a professor with extension and research responsibilities in corn and soybeans. She has a general background in integrated...