The kudzu bug is fairly easy to control. Spray a pyrethroid, and it’s gone. The spray also takes out beneficial insects that keep other soybean pests down. The field may be free of kudzu bugs, but it could later be overrun with soybean looper and caterpillar pests that are just as destructive. So the grower has to keep spraying.

N.C. State University Extension specialist Dominic Reisig wants to find a way to keep growers with kudzu bug problems out of the “spray continuum.” So he and his colleagues from South Carolina and Georgia will use a $168,644 U.S. Department of Agriculture Southern Regional IPM grant to find out why kudzu bugs leave their home in kudzu patches to move to soybean fields.

Kudzu bug has been in the U.S. only since 2009, where hundreds of them covered the outside of houses in Atlanta, Ga. From there it has spread throughout the South, covering the entirety of the Carolinas and Georgia, and parts of Virginia, Tennessee, Alabama, Florida, Mississippi and Louisiana.

Although it feeds on the voraciously invasive kudzu weed, the pest is a nuisance in residential areas and a disaster in a soybean field. Kudzu bugs reduce soybean yields on average about 20 percent in a field that hasn’t been sprayed, and they reproduce so rapidly that a field can be overrun with them in just a few days. So many farmers spray an insecticide when they see kudzu bugs start to multiply, only to find that the rest of the growing season is a continuing battle with other pests.

Kudzu bug got its name for its affinity for kudzu, in which the bug lives after coming out of its overwintering slumber. In May, kudzu bug migrates to soybean fields.

“Kudzu bugs overwinter behind tree bark,” Reisig says. “They particularly like the loose bark of pine trees. We’ve also found them below broadleaf litter. From there they move to kudzu, so we think kudzu is an important bridge host.”

Reisig and his colleagues are especially interested in why kudzu bug leaves kudzu in the first place, along with the distance that the pest can fly between a kudzu patch and the nearest soybean field.

“We want to know what kind of risk a grower is in if the soybean field is near a kudzu patch,” Reisig says.