Soybean Aphids Look Like Gnats But Pose Big Problem for Farmers

The soybean aphid was first discovered in Illinois just nine years ago, but an expert says this growing season was the first time the insect has made its presence known downstate.

University of Illinois crop sciences professor Mike Gray says this year's cooler weather lured aphids to Central and Southern Illinois - and that many people confuse the tiny insects with gnats. They use their needle-like mouths to remove fluids from the soybean plant early in the growing season.

Gray says the aphids will seek out two different plants to survive. He says they must feed on soybeans during much of their life cycle... but they will also seek out buckthorn, or woody perennials found along fence rows to exist and reproduce during the next few months:

"Next year after winter, a soybean plants begin to emerge in farmers' fields, we'll get the formation of winged aphids again", says Gray. "And they will fly from buckthorn into these emerging soybean fields. And they'll spend the summer and the growing season out there."

A single soybean plant can contain hundreds of aphids, or thousands if they go untreated by insecticide. Gray says farmers need to address the problem by July or early August.