Cockroach bait kills multiple roach groups: study

CHICAGO (Reuters) - A single dose of a new insecticide killed cockroaches that ate it and other roaches that fed off their bodies, U.S. researchers said on Monday in findings sure to cheer urban dwellers everywhere.

"Our findings are exciting because cockroaches are difficult to control since they multiply so rapidly," said Grzegorz Buczkowski, an entomology professor at Purdue University in Indiana, whose study appears in the Journal of Economic Entomology.

"They are especially bad in urban housing, and they can cause health problems," Buczkowski said in a statement.

Cockroaches are hard to kill because they lurk in dark places, coming out at night to feed. When they find a cozy spot to live, they leave behind a chemical trail of pheromones in their feces to attract other cockroaches.

Buczkowski's team studied German cockroaches, a shiny, orange-tinged roach that is among the most common household species in the United States. The team was testing the effectiveness of Du Pont Co's Advion Cockroach Gel, which uses the chemical indoxacarb as its active ingredient.

The gel, besides killing the adults that ate it, had a kill rate of 76 percent when the youngest roach nymphs, known as instars, were infected with the poison.

The poison also killed 81 percent of adult male cockroaches that fed on the bodies of the roach nymphs. All the roaches were dead within 72 hours of their first exposure to a cockroach poisoned with indoxacarb.

The Purdue Industrial Affiliates Program and DuPont funded the study. Buczkowski has no financial ties to DuPont or its insecticide.

(Editing by Peter Cooney)