Soybean Gall Midge Adult Emergence Begins

June 17, 2022
ICM News

This week, the first soybean gall midge adults (Photo 1) were collected in Iowa near Wall Lake in Sac County (Monday) and near Sutherland in O’Brien County (Thursday). This is similar to when soybean gall midge emergence was first detected in Iowa in 2021. The first Midwest report of soybean gall midge emergence in 2022 was on June 7 near Davey, Nebraska. You can keep up with soybean gall midge emergence at soybeangallmidge.org/. We will also send text updates on soybean gall midge activity in Iowa through the Iowa Pest Alert Network this summer.

Soybean gall midge adults.
Photo 1. Soybean gall midge adults. It is unlikely you will see soybean gall midge adults in the field unless emergence cages are used. Photos by Justin McMechan, University of Nebraska-Lincoln.

Typically, plant injury is noticeable and larvae can be found feeding within stems a few weeks after adult emergence. Begin scouting for soybean gall midge larvae now, especially if plants are at least V2. Start scouting at the edge of soybean fields adjacent to fields that were infested last year or, if infestations were not noted last year, begin at the field edge near last year’s soybean. A black lesion is usually noticeable at the base of the plant (Photo 2). Look for white or orange larvae feeding inside soybean stems (Photo 3) by using your fingernail or a knife to split the stem. Early in the season, infestations might be noticeable if random plants are dead or wilting among otherwise healthy-looking plants (Photo 4). This becomes less obvious later in the season as the canopy closes.

Photo 2. A black lesion at the base of a plant likely indicates there are soybean gall midge larvae inside.
Photo 2. A black lesion at the base of a plant likely indicates there are soybean gall midge larvae inside. Peel back the epidermis to expose larvae. (Photo by Ashley Dean.)

 

Soybean gall midge damage.
Photo 3. White (1st or 2nd instar) or orange (3rd instar) larvae can be found by peeling back the layers of the stem or splitting the stem. (Photos by Ashley Dean.)

 

Dead, wilted soybean plants.
Photo 4. Dead, wilted plants can be found amongst healthy-looking plants. Infestations tend to begin at the field edge. (Photo by Ashley Dean.)

Unfortunately, there are no known, effective management strategies to suppress larvae at this time. This summer, universities around the Midwest continue to monitor the distribution and evaluate potential management strategies. Read more about soybean gall midge identification, biology, and scouting in this encyclopedia article.

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, 2022. The information contained within may not be the most current and accurate depending on when it is accessed.

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Authors: 

Ashley Dean Agriculture and Natural Resources Extension Specialist II

Ashley is an education extension specialist for field crop entomology at Iowa State University. She coordinates the Iowa Moth Trapping Network, the Regional Corn Rootworm Monitoring Network, and the Iowa Pest Alert Network. She also develops educational resources for field crop pests in Iowa and ...

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...