Monday, July 1, 2013 — Now that research has determined why some German cockroaches are averse to glucose, scientists want to know if some of those roaches are also resistant to the insecticide used in roach baits, and if they are, how they can be controlled.
After discovering the basis behind an adaptation that renders some German cockroaches averse to glucose, NC State researchers Dr. Jules Silverman and Dr. Coby Schal want to find out if glucose-averse roaches could also be resistant to the bait toxin. Glucose, or sugar, is used in roach baits, which contain insecticide, to attract roaches.
However, some roaches have evolved to become glucose-averse. These roaches aren’t attracted by glucose, so they tend not to consume insecticide baits.
Silverman and Schal already have some evidence that some cockroaches not only avoid bait, but if they do consume it, they survive effects of the toxin. With a $30,000 IPM Enhancement grant from the Southern IPM Center at North Carolina State University, they intend to find out if the two traits are linked, and if they are, what can be done to control this new breed of cockroaches.
Cockroach baits have been in use since 1982, when they replaced baseboard sprays typically used by pest management professionals to kill cockroaches. In 1988, a pest management professional in Gainesville, Fla., began reporting an increase in the number of cockroaches in a building after baits had been used continuously. Reports of bait failures began in other states as well.
In a study published May 24, 2013 in the journal Science, Silverman and Schal revealed that some cockroaches have inherited a neural adaptation that causes them to avoid glucose. The study was described in a May 23 story released by NC State University. Now the scientists are studying whether these and other German cockroaches might also be resistant to the bait’s active ingredient.