Agronomy Tip: Understand Corn Rootworm

As corn rootworm continues to plague farms in the Midwest, it is best to understand how this pest behaves.

“Because corn rootworms are below ground, often times we don’t know that they’re there until we have some above-ground symptoms,” Paul Parcher, Technical Agronomist for Channel Seed explains. One example is lodged corn after strong windstorms, which may occur due to the loss of root tissue caused by corn rootworm larval feeding.

Corn rootworm populations can fluctuate rapidly from year to year, Parcher says. Corn rootworm eggs are well adapted to the harsh Midwestern winter conditions. The addition of an insulating blanket of snow aids in their survival, but if there is soil saturating rainfall at the time of hatching, many corn rootworm larvae may drown. In dry conditions, because the pest feeds on roots and interferes with the plant’s ability to uptake nutrients and water, the crop may show symptoms of drought and/or nutrient deficiency earlier than the weather may indicate.