Clemson University researchers, together with a counterpart at the University of Georgia, have teamed to study a bug species they believe poses a serious threat to agriculture in the Southeast.
In the three-year study they hope to get a greater understanding of the stink bug to reduce pesticide use, saving farmers time and money and protecting Mother Nature’s natural order.
Stink bugs, so named because they secrete a foul-smelling liquid that is repulsive to most predators, gnaw on some of the region’s most important crops, including wheat, cotton, corn, peanuts, soybeans and tobacco.
The bugs generally feed on the fruiting structures of the plant. In cotton, for example, they pierce the small cotton boll — the seedpod of the cotton plant — and suck sap from the seeds.
This reduces the amount and quality of cotton fibers that develop within the boll. As a result, stink bugs can significantly reduce yield.
The Clemson researchers are entomologists Francis Reay-Jones at the Pee Dee Research and Education Center in Florence and Jeremy Greene at the Edisto Research and Education Center in Blackville, and economist Carlos Carpi on the main campus. They are joined by Michael Tows, an entomologist at the University of Georgia.
The team was awarded $154,000 from the U.S. Department of Agriculture Southern Region Integrated Pest Management program to study the farmscape ecology of stink bugs.
Their research could lead to substantial reductions in insecticide use to control stink bugs in cotton, a major susceptible crop in the Southeast. The team will evaluate the cost of implementing the research for practical and commercial applications.
In the Southeast, a typical farm has numerous small fields that often are close to each other in a configuration called a farmscape. Regions around the country have different farmscapes. For example, fields in the Midwest often are much larger.
Stink bugs move in patches within a farm, Reay-Jones said. Part of the study's first objective is to sample stink bugs and their natural enemies concurrently across different fields. If the researchers can determine when stink bugs move into a crop and at which location in the farmscape, planting methods may be altered to help keep the pests at bay.
“We want to have a better understanding of the ecology,” he said. “We want to quantify where they build up in a farmscape and at what point during the season they move from one crop to another.”
The researchers will employ Geographic Information System technology to map the study areas as a grid and precisely monitor the insects across the farmscape.
The study also will evaluate in-field border applications of insecticide, specifically in cotton, with the objective of reducing insecticide use. Researchers know that stink bugs infest cotton fields from the edge first and move toward the interior of the field, said Greene.
Rather than applying insecticides over the entire field, test applications will be made only across the first 40 feet of a field’s perimeter. Such application may eliminate the need to treat the entire field. That can reduce the use of chemicals on a field, save time applying the pesticides and conserve natural enemies.
“Typically, when a crop starts blooming that’s when we see insects move in,” Greene said. “If you can get there early enough and initiate these applications at the right time, you may be able to prevent their colonization of the field.”
Once considered secondary pests in the United States, cotton crop losses caused by stink bug damage were estimated at $60 million in 2002. The pests infested 6.5 million acres of cotton in 2006 and destroyed more than 151,000 cotton bales.
“Stink bugs are going to be the No. 1 insect pest of cotton in the Southeast,” Greene said.
The study will be conducted at the Pee Dee and Edisto research and education centers, on two fields on a private farm in Cameron, S.C., and in fields in Tifton, Ga.