June 12th Update:
According to the Friday alert from Nebraska Extension, soybean gall midge adults have emerged from multiple sites in eastern Nebraska. The June 12th update indicates soybean gall midge adults have emerged in monitoring sites in Cuming County (1 adult detected), three sites in Saunders County (1 adult at each), two sites in northern Landcaster County (1 adult at one site, 2 adults at the other site), and in Cass County (2 adults at one site, 3 total adults at a different site). Also, the alert network website shows one soybean gall midge adult has been captured at sites in Cass and Ida counties in Iowa.
See the alert web site and latest information here: www.soybeangallmidge.org.
For soybean growers that are near the site with adult activity and that have had issues with soybean gall midge, they may consider making an application in the next week if their soybean fields have reached the V2 stage. Based on last year’s data from Nebraska Extension, soybean plants prior to the V2 stage generally lack the presence of cracks or fissures at the base of the stem. Plants without fissures are not considered to be susceptible to soybean gall midge infestation. If growers have fields at VC or V1, NE Extension Cropping Systems Specialist Justin McMechon recommends waiting until V2 to make an application if they are in a high-risk area and have adult activity occurring.
In 2019, pyrethroid insecticides applied at different timings relative to adult emergence showed a significant yield response in Nebraska when applied up to 10 days after the first adult emergence was detected. McMechon says it’s important to note that none of those treatments provided complete control of soybean gall midge. In addition, the study was conducted on a field that was planted to soybean the previous year. Since soybean gall midge is a field edge infesting pest, growers may only need to treat the first 60 to 120 feet of a field edge that is directly adjacent to a field that was injured the previous year.