Chemical Lures For Cockroaches

Stale beer and peanut butter are all but irresistible to that most pervasive of pests—the cockroach. Biologists at Simon Fraser University, in Burnaby, British Columbia, have now sussed out the semiochemicals, or message-bearing chemicals, in these foodstuffs that make roaches come running (J. Agric. Food Chem., DOI: 10.1021/jf103621x). To identify candidate semiochemicals, a team led by Gerhard J. Gries used gas chromatographic/mass spectrometric analyses in combination with coupled gas chromatographic/electroantennographic detection, wherein a cockroach’s antennae are hooked up to the instrument and used as a detector. The candidate chemicals were then screened in elaborate olfactometer experiments. A combination of ethanol and the pyranone DDMP make the bugs thirst for beer, whereas 1-hexanol piques their interest in peanut butter. The researchers believe the attraction to DDMP, which is formed from the reaction of an amino acid and a reducing sugar, generally indicates to roaches the presence of sugar, whereas 1-hexanol signals the presence of lipids. These compounds, they say, could be used as bait in roach abatement programs.