Published on 10/28/04

Insect-light cotton crop, some bugs still stink

By Brad Haire
University of Georgia

Fall tropical storms and hurricanes blew a lot of Georgia's cotton away before it could be harvested. But at least the bugs weren't bad to the crop during the growing season, says a University of Georgia expert.

"There were some localized problems with insects," says Phillip Roberts, an entomologist with the UGA Extension Service. "But there were no problems widespread. It was overall an excellent year as far as insect pressure."

Stinkbugs, though, are still causing some problems for Georgia cotton farmers. A stinkbug pierces the cotton bolls, where the lint develops, and feeds on the young seeds inside. Too many stinkbugs can hurt yields.

But stinkbug damage has also been linked to Georgia cotton quality problems, something that has started to give Georgia's cotton a bad name.

Only in recent years have stinkbugs become problems for Georgia farmers. They were particularly bad in 2003, Roberts said.

In the past, insecticidal sprays that targeted other pests killed the stinkbugs, too. But more than 80 percent of Georgia's cotton acreage is now planted to what is called Bt cotton.

Bt cotton is a transgenic variety. It has a gene that allows the plant to produce a toxin from the bacterium, Bacillus thuringiensis. This toxin kills many cotton caterpillar pests.

Before Bt cotton came in the mid-1990s, Georgia farmers sprayed insecticides about five times per year. They spray only about twice per year now.

But Bt doesn't kill stinkbugs. Many growers have started to spray just for them, Roberts said. This year, stinkbug damage wasn't as bad as last year.

"If the growers continue to scout for stinkbugs and spray when they should, it will help them with their cotton quality," he said.

The Georgia Boll Weevil Eradication Program this year reported trapping two boll weevils, one in Appling County and one in Wilcox County. Last year, trappers with the Georgia program captured zero boll weevils, the first time that had happened since the program began in 1987.

The boll weevil began to devastate Georgia cotton in the 1920s. It was officially considered eradicated in the state in 1994.

Georgia farmers planted 1.26 million acres of cotton this year. UGA Extension Service county agents and specialists estimate that as much as 30 percent of the crop was lost to tropical storms.

Brad Haire is the former news editor with the University of Georgia College of Agricultural and Environmental Sciences.