College of LAS « Illinois

Entomology

Exploring the World, One Taste at a Time

How moths and honeybees explore their surroundings.

moth

Alone in an unfamiliar place, we might look around or listen. But many insects explore by smelling or tasting their surroundings. Now new results from LAS entomologists reveal how moths use tiny odor sensors to find mates and how honeybees survey their surroundings.

Male hawk moths have antennae exquisitely tuned to detect potential mates; the antennae are packed with receptors that detect the scent of female pheromones. Entomology professor Hugh Robertson and graduate student Harland Patch ground up several thousand male moth antennae and cloned all the active genes. Two of them, it turned out, resembled known insect odorant receptors. To find out for sure if the genes encode pheromone receptors, the two will soon engineer the two genes into fruit flies and test whether a whiff of moth pheromone sends signals to the flies' brains.

Other insects explore their world by tasting objects around them. Fruit flies, for example, taste with their legs as well as their mouth, and the fruit-fly genome contains 68 different taste-receptor genes. But by probing a recently completed draft of the honeybee genome—a project led by entomologist Gene Robinson—Robertson and his colleagues found that honeybees had just six. The results suggest that the honeybees need fewer taste receptors because their larvae don't have to forage for food inside the hive, and because adults explore in large part by touching things with their antennae, Robertson says. The results make sense, he adds, because bees and fruit flies have "incredibly different ecologies."

Summer 2004