Sugar isn’t always sweet to German cockroaches, especially to the ones that avoid roach baits.
In a study published May 24 in the journal Science, North Carolina State University entomologists show the neural mechanism behind the aversion to glucose, the simple sugar that is a popular ingredient in roach-bait poison. Glucose sets off bitter receptors in roach taste buds, causing roaches to avoid foods that bring on this taste-bud reaction. This aversion has a genetic basis and it eventually spreads to offspring, resulting in increasingly large groups of cockroaches that reject glucose and any baits made with it.
In normal German cockroaches, glucose elicits activity in sugar gustatory receptor neurons, which react when exposed to sugars like glucose and fructose – components of corn syrup, a common roach-bait ingredient. Generally, roaches have a sweet tooth for these sugars. (more…)