• 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.
South Carolina outlook
South Carolina growers can also their normal insect problems in 2012, Greene says. “Although we didn’t have widespread problems with stink bugs in 2011, they are still perennial pests that we deal with in soybeans. We also have sporadic problems with corn earworms in some areas, as well as defoliating insects including the velvetbean caterpillar and the soybean looper.”
(Additional information on the kudzu bug in South Carolina can be found at http://southeastfarmpress.com/soybeans/kudzu-bug-chewing-south-carolina. Background on the pest can be found here).
In Arkansas, as well as other Mid-South states, the corn earworm has been the biggest soybean insect pest for the last two years.
“Of all the insect pests, it is the single biggest insect threat to soybean yields,” says Gus Lorenz, Arkansas Extension IPM specialist, Lonoke.
“We had extremely high numbers in 2010 and they were even higher in 2011. We saw early problems behind pyrethroid applications, so we began tank mixing with Orthene and other materials. We also used a new Bayer chemistry, Belt, which worked extremely well.
“Our big bollworm problems in 2011 were a result of flooding in the spring. Growers can help themselves by planting early whenever weather permits. Early planted beans often will avoid these bollworm populations.”
Additionally, fields not lapped at bloom were the ones that were most severely affected bybollworms.
“For some reason, most Lepidoptera pestsare attracted to open canopy beans, particularly with the bollworm, but also with the armyworm complex; even loopers are worse in beans with an open canopy,” Lorenz says.
“So, anything growers can do to achieve canopy closure prior to bloom will be helpful. That includes planting early, and maybe closing up rows.”
Mississippi’s production practices of planting more corn, more Group V beans, and more wheat beans mean that the state’s soybean growers will continue to have problems with corn earworms and loopers, says Angus Catchot, Extension entomologist at Mississippi State University.
“We plant a large portion of our soybeans late so we can manage the harvest of all of our different grain crops,” he says. “As long as we continue to do that, we’ll have problems with corn earworms and loopers, which will be our No. 1 and No. 2 pests, respectively, going into 2012.
“The impact of these pests can be minimized by planting early and avoiding mid-May planted beans. But we can’t plant our entire crop early, so we have to manage it by scouting and spraying when economic thresholds are reached.