Archive of 2023 Soybean Gall Midge Alerts
June 22nd, 2023: Map Updates Now Include Larval Presence and Wilting Plants at Monitoring Sites
Soybean gall midge larvae have been found at adult emergence monitoring sites in NE, IA, and MN. The soybeangallmidge.org website map has been updated to provide information on the presence of larvae and wilting or dead plants at each monitoring site. On June 19th, adults were collected from a current year’s soybean field in east central NE, marking the start of the first generation from this year’s soybean. Adults are still emerging from last year’s soybean fields (overwintering generation) at some sites. We expect adult emergence from last year’s soybean for a few more weeks based on data from previous years.
Soybean Gall Midge Found in Kansas and Confirmed in North Dakota
Soybean gall midge was found on soybean and sweet clover in northern Kansas. This is the first detection of soybean gall midge in Kansas. In addition, samples collected in southeast North Dakota last summer were identified as soybean gall midge through DNA sequencing.
It’s a good time to scout your fields!
This is a good time to get out and scout your soybean fields. See the scouting page on soybeangallmidge.org for details on how to scout your fields.
Join us for a Regional Field Day on June 25th at the Eastern Nebraska Research, Extension and Education Center.
Talk with entomologists that are working on soybean gall midge and see the insect and several management practices first hand. Registration is limited; reserve your spot through the link on soybeangallmidge.org.
Registration Link: https://go.unl.edu/register2023july25soygall
June 8th, 2023: Adult Emergence in NW IA and Larvae in east central NE
Two male soybean gall midges were captured at the ISU Northwest Research Farm near Sutherland on Tuesday (June 6). This is about one week earlier than the previous first captures in Iowa. We encourage you to scout soybean at the edge rows after V2 for signs of larval infestation.
White larvae (early development stage) were found on volunteer soybean near Syracuse and early planted soybean near Mead, NE, on June 7th. The frequency of infested plants was low at both sites, and only a few larvae were found on the infested plants.
All sites except one in east-central NE have had some level of adult activity. In northeast NE, one of three sites has had adult activity.
No adults have been detected in Minnesota or South Dakota.
May 31st, 2023: Soybean Gall Midge Emergence in Nebraska
On May 31st, soybean gall midge adult emergence was observed in east-central Nebraska near Mead. (Fig. 1). No adult emergence has been dectected at any of the other sites in the alert network. A planting date study at the Eastern Nebraska Research, Extension, and Education Center near Mead, NE shows that soybean planted from April 23rd to May 3rd are at the V2 stage when fissures occur (Fig. 2). Later planting dates (May 13th) are still at the V1 stage. Only soybean with fissures present are susceptible to soybean gall midge infestation.
Figure 1. Soybean gall midge alert network trap sites with a yellow dot indicating activity and the number of adults collected at that site.
We advise growers to wait for continued emergence of soybean gall midge adults before taking any action. No research is available on the impact of hot and dry weather on adult emergence, but it is possible that there may be some early emergers. Management of soybean gall midge has been difficult. Foliar sprays have shown some response but are inconsistent between locations and years. No specific foliar applied product tested to date has provided consistent control of SGM. Research to date suggests that growers can consider using a combination product that contains a pyrethroid. If an application is being considered, it should only be made in soybean fields where a history of issues with soybean gall midge injury has occurred. 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. Do not treat any soybean fields prior to V2 as they are not susceptible to infestation due to the lack of fissures or cracks at the base of the stem
Hilling or covering the base of soybean stems with soil has also been found to be a very effective strategy with almost complete control of soybean gall midge. This is a difficult practice to implement when soybean plants are small, as they can easily be completely covered by soil. Studies are being conducted to evaluate the timing of hilling relative to the plant development stage. More information on hilling is available through the soybeangallmidge.org website. Little is known about the impact this management strategy could have on soybean gall midge movement in a field. Although no field studies have been conducted, it is possible that adults may continue to move into the field until they find a susceptible plant.
With no detection of soybean gall midge in other parts of the network, it would be advisable to wait for emergence to occur in those areas. You can continue to follow adult emergence at all locations through soybeangallmidge.org.
Soybean Gall Midge: Should I Spray Checklist
❏ Soybean gall midge adults have emerged in my area
❏ My soybean field is at the V2 stage or greater
❏ I observed soybean gall midge injury in the adjacent field last year
Figure 2. Soybean plants (a) at V1 and V2 stage with close up of the stem (b) showing differences in the formation of fissures or cracks at the V2 stage.