• The kudzu bug is a new insect pest that has invaded the Southeast and is probing the Mid-South.
• Researchers observed a 19 percent average yield loss in Georgia trials in 2010, and even greater losses in 2011. In five trials yield loss ranged from 22 percent to 47 percent.
• Growers definitely need to scout for the kudzu bug and treat if necessary.
For the 2012 insect outlook, southern soybean growers can expect a new kid on the block — the kudzu bug — as well as the usual suspects.
Several Southeast and Mid-South university entomologists discuss potential insect problems, and what growers can do about them.
The kudzu bug is a new insect pest that has invaded the Southeast and is probing the Mid-South.
“In the fall of 2009, the kudzu bug was first found in the U.S. in nine northeast Georgia counties,” says Phillip Roberts, Extension entomologist, Tifton, Ga. “Today, it’s in 120 counties of Georgia, all of South Carolina, 50 North Carolina counties, one Virginia county, and five Alabama counties.
“We observed a 19 percent average yield loss in Georgia trials in 2010, and even greater losses in 2011. We harvested five trials and our yield loss ranged from 22 percent to 47 percent.
“Growers definitely need to scout for the kudzu bug and treat if necessary. We’re still developing workable thresholds; we suggest treatment when you find three to five bugs per plant.”
While Georgia researches ways to control the new pest, the state still contends with its regular insect problems. The state’s primary pests are pod feeders, mainly stink bugs.
“We also have a complex of foliage feeders, with the velvetbean caterpillar and soybean looper being the primary ones,” Roberts says. “We’ve also had some tough situations with lesser corn stalk borer, which is a sporadic pest for us.”
In 2010, the kudzu bug was found in 16 out of 46 South Carolina counties. Its population exploded and completely covered the state in 2011.
Jeremy Greene, Clemson University entomologist, Blackville, S.C., says, “Depending on factors such as planting date, maturity group, and others we are just beginning to learn about, yield losses from this insect range from zero to 50 percent loss if not controlled.
“We’re still researching cultural methods to control this pest. The kudzu bug responds well to insecticides, but it’s not listed on any insecticide label. We can still legally, but carefully, make recommendations to producers for using insecticides already labeled in soybeans, but we will have to work with the chemical companies to get this pest added to their labels and recommended in ways that will provide good control.
“We have generated some data, but need to initiate more trials, showing which products are efficacious on this insect. We have only had 2011 to do any appreciable field research on this species. We are currently planning for significant research next year.”