
Bats Enlisted to Gobble Up Earworm Pests By Linda
McGraw May 5, 1999In early June, billions of corn earworm
moths emerge from the Lower Rio Grande Valley along the border of Texas and
Mexico. Some moths feed on cotton after leaving southern corn, while others
travel north to ravage midwestern corn crops. Each year, these pests cost
farmers about $2 billion in losses and control costs. To control the moths, Agricultural
Research Service scientists in College Station, Texas, are capitalizing on
the voracious appetite of Mexican free-tailed bats. Corn earworm moths are one
of the bats favorite foods. A million bats can gobble up nearly 10 tons
of insects in just one night. So the 20 million bats living in Bracken Cave
near San Antonio, Texas, could put a real dent in moth populations. ARS meteorologist John K. Westbrook, who has studied moth migration for 17
years, knows that bats and moths typically fly at about the same altitude. His
collaborative work with bat specialist
Gary
F. McCracken of the University of
Tennessee and Merlin Tuttle of Bat
Conservation International is secondary to his main interest: moth
migration. To confirm the bats appetite for moths, Westbrook attached
radiomicrophones to helium-filled balloons called tetroons. While the tetroons
drifted at an altitude of about 2,500 feet, the researchers could hear and
record the high-frequency sounds of bats searching for and feeding on moths. The National Weather Services
Doppler radar system (NEXRAD) helps the researchers detect masses of moths more
than 60 miles away from a radar site, one of which is located in Brownsville,
Texas. Like firefighters putting out the hot spots first, the
NEXRAD radar research may be used to develop time-critical maps to help control
moth infestations over a large area. ARS Areawide Pest Management Research in College Station has one of the most active radar-entomology research programs in the world. An article about the research appears on the May issue of Agricultural Research magazine and can be found on the world wide web at: http://www.ars.usda.gov/is/AR/archive/may99/pest0599.htm
ARS is the USDAs chief research
agency. Scientific contact: John K. Westbrook, ARS Areawide Pest Management
Research Unit, College Station, Texas, phone (409) 260-9351, fax (409)
260-9386, [email protected]. U.S. Department of Agriculture | |