Soybean Gall Midge Found in South Dakota Field

By Jamie Martin

Soybean gall midge larvae are now detected in southeastern South Dakota soybean fields. These pests are known to affect plant health, especially near the field edges. Farmers may notice soybean plants wilting or dying along borders, which can often be linked to this pest.

A dark or discolored area appears on the outer layer of the plant stem, signaling the larvae' presence. Over time, affected plants may weaken. While not all plants die, those near the edges—especially last year’s soybean stubble—are more likely to wilt and die.

This is because soybean gall midge adults are weak fliers. They often start infestations at the edges of fields, close to where soybeans were previously planted. As the season continues and new generations of the pest develop, the infestation spreads inward toward the middle of the field.

 There are currently no rescue treatments available to stop soybean gall midge once the larvae are inside the plant. That makes prevention and early detection extremely important.

Farmers are advised to scout regularly, especially the areas bordering last year’s soybean fields. Spotting early symptoms can help them understand the extent of the problem and make better decisions for future planting and pest control.

Although the damage may not affect the entire field, untreated infestations can cause serious yield loss around the borders. Awareness and monitoring are key tools in managing this pest.

Photo Credit: gettyimages-gilaxia