Figure 1. Confirmations of gall midge larvae in soybean in 2018. Positive counties are shaded in red.
In South Dakota, a lot of soybean fields are naturally beginning to change colors as soybean senescence has started. This is going to greatly affect how we determine whether or not fields are infested with gall midge larvae. The infestation indicators that will still be useful is the presence of white fungal growth on the base of the plant and soybean plants easily breaking near the soil surface. As we move forward towards the 2018 harvest, it is going to be important to monitor fields for excessive lodging, as these will likely indicate areas that were affected by gall midge larvae.
To date, gall midge larvae have been confirmed in Brookings, Clark, Clay, Codington, Davison, Deuel, Douglas, Edmunds, Hamlin, Hanson, Hutchinson, Kingsbury, Lincoln, Miner, Moody, Spink, Turner and Union counties (Figure 1). We ask that everyone continues to monitor soybean fields for the presence of gall midge. If you believe you have a gall midge infestation, please consider contacting us prior to harvest so that yield strips may be established in your fields.
The best way to confirm gall midge larvae infestation of a field is to send an image of the infested plants along with the following information:
- Previous Crop.
- Tillage Practice.
- Seed Treatments Used.
- Occurrence in the field edge or entire field.