Scientists Seek Microbial Bait Against Termite Pest

By Jan Suszkiw
January 31, 2000

Baits laced with spores of naturally occurring fungi or bacteria may help dampen the Formosan termite's appetite for destruction.

Scientists with USDA's Agricultural Research Service are exploring the possibility in lab studies begun in October at the agency's Southern Regional Research Center in New Orleans, La. There, damage from Formosan termite infestations costs the city's residents and suburban neighbors $300 million annually.

The New Orleans studies are the first to examine potential pathogens of the termite collected in its native southern China, and returned to the U.S. under quarantine. At the ARS center's Formosan Subterranean Termite Research Unit, scientists are trying to identify the pathogenic microbes, and determine which produce spores that could be used in commercial bait products.

Those now used employ wood or paper-based materials to encourage foraging termites to contact slow-acting chemical toxins hidden inside, and spread them to nestmates. But scientists want to find out if replacing the toxins with a microbial ingredient will offer a natural alternative. Another possibility is to dust fungal spores onto termite nest areas.

The microbes behind such possibilities include known insect pathogens from the U.S. and potential pathogens obtained in China and Australia by ARS entomologist Janine Powell, based in Mississippi, another termite-plagued state. From her specimens, the New Orleans team is seeking microbes that will specifically attack the Formosan termite, spread throughout its colonies, and withstand the insects' physical and chemical defenses.

One candidate pathogen is an Australian strain of Metarhizium fungus. In lab trials, up to 100 percent of Formosan termites died two days after exposure to millions of the fungus' spores. Early next summer, scientists will test it in a new ARS termite bait "matrix" along with commercial products. The baits are central to an area-wide termite control project planned for Mississippi's Gulf Coast. Baits laced with imported microbes may require EPA approval.

ARS is the USDA's chief scientific wing.

Scientific contact: Janine Powell, Maureen Wright, ARS Formosan Subterranean Termite Research Unit, New Orleans, La. Wright: phone (504) 286-4294, fax (504) 286-4419, mwright@nola.srrc.usda.gov. Powell (Stoneville, Miss.): phone (662) 686-5282, fax (662) 686-5281, powellj@ars.usda.gov.