Soybean gall midge strikes Kansas counties

By Scout Nelson

In a concerning development for soybean farmers, the soybean gall midge has been detected in Nemaha and Marshall counties in northeast Kansas. This pest, which was first spotted in neighboring Nebraska counties, has now crossed into Kansas, bringing potential agricultural challenges.

Anthony Zukoff, an entomologist at Kansas State University, reported that this pest causes significant damage, particularly at the edges of fields where infestations often start.

"From the field edge, which is where the infestations typically start, to about 100 feet into the field you could have complete yield loss," Zukoff explained. Beyond this area, losses may reduce but still reach up to 20% yield loss at distances of 300 to 400 feet from the infestation point.

The soybean gall midge is a tiny fly that lays its eggs in soybean fields. The emerging larvae feed on the inside of the stems, causing the plants to lodge and die, which can drastically reduce the yield.

To identify this pest, Zukoff urges farmers to look for wilting plants with swollen, darkened stems at their bases. Cutting open these stems may reveal bright orange maggots, a distinctive sign of infestation.

"If you see symptoms like that (wilting, swelling, and dark coloration), cut the plant down the middle and look for maggots inside the stem," he advises.

Effective insecticide treatments for the soybean gall midge are lacking due to the novelty of the issue. However, Zukoff suggests alternative strategies such as crop rotation or avoiding planting next to heavily infested fields. Some cultural techniques, like hilling soil around the bases of plants early in the season, are being explored though their practicality varies.

The soybean gall midge is recognizable by its small size, bright orange body, mottled wings, and striped legs. With no practical insecticide recommendations available yet early detection and alternative management strategies are critical for controlling this pest.

Farmers are encouraged to report any sightings to their local extension offices or directly to the Kansas State University entomology department to help track and manage this emerging threat.

Photo Credit: istock-oticki