September 20, 2006

 

Insects threatening soybean crop in US state Arkansas

 

 

Stink bugs and caterpillars are threatening soybean crops in Arkansas, and experts are advising farmers to take action before their fields get eaten up.

 

Stink bugs are appearing in great numbers, especially in south-eastern Arkansas. Gus Lorenz, an entomologist with the University of Arkansas Cooperative Extension Service, said their numbers are 12 times the amount when it's advisable to treat with pesticides.

 

"They've been building all year, moving from early season soybeans to mid-season soybeans and now to late-season beans," he said. "Their numbers have magnified each time they move as they became more concentrated in fewer fields."

 

A stink bug damages a soybean in the pod by injecting it with a toxin that makes it easier for the insects to suck out the juices. It also reduces bean quality and yield.

 

Meanwhile, a type of caterpillar called a looper has become a serious problem across the state. Lorenz says if fields are still green, farmers should get an estimate on the numbers of stink bugs and loopers and treat accordingly.

 

Don Plunkett of the Jefferson County Cooperative Extension Service stressed that farmers need to be in the late-planted soybean fields scouting for insects.

 

"Their attention is focused on harvesting rice, corn and soybeans," he said. "They don't want to look because they're tired of spending money on the crop, but a lot of late-planted beans may have high-yield potential if they're on irrigated ground."

 

Loopers are voracious eaters and can quickly defoliate a crop.

 

Lorenz said that farmers have to be on the look out constantly for loopers. If they damage the top of the plant, it will be too late as these insects feed on leaves at the bottom and moves up.

 

"With the numbers as high as they are, producers are going to see some serious losses if they don't treat" he said. "It's not wise to save a US$8 to US$10 application to lose as much as 20 percent of your yield. You can't afford not to spray."

 

Plunkett said if farmers find loopers and 25 percent defoliation in their soybeans, they should treat. He said stink bugs and looper numbers can be determined by using either a shake sheet or sweep net to capture them.