0
Facebook
Volume 91 Issue 6 | p. 32 | Concentrates
Issue Date: February 11, 2013

Grooming Keeps Insect Senses Sharp

Cockroaches and other bugs clean their antennae to remove chemical buildup that could block detection of food, mates, and danger
Department: Science & Technology | Collection: Life Sciences, Critter Chemistry
News Channels: Biological SCENE
Keywords: insect grooming, cockroaches, antennae, olfactory sensing, pheromones, insecticides
To study insect grooming, researchers at NC State and the Russian Academy of Sciences prevented cockroaches from cleaning one of their antennae by affixing a rigid plastic ring around it. In this video clip, the insect continues to groom the free antenna and struggles to catch hold of the restrained one.
Credit: Courtesy of Ayako Wada-Katsumata
[+]Enlarge
When left ungroomed, cockroach antennae become fouled with hydrocarbon gunk (left); normally the bugs keep their sensory organs nice and clean (right).
Credit: Proc. Natl. Acad. Sci. USA
Two SEM images of cockroach antennae. On the left, the spines barely stick out of a an amorphous mat of waxy-looking goo. On the right, the spines are clean and the follicles from which they emerge are visible.
 
When left ungroomed, cockroach antennae become fouled with hydrocarbon gunk (left); normally the bugs keep their sensory organs nice and clean (right).
Credit: Proc. Natl. Acad. Sci. USA
[+]Enlarge
Credit: Courtesy of Ayako Wada-Katsumata
A cockroach grooming its antenna.
 
Credit: Courtesy of Ayako Wada-Katsumata

Unlike humans who groom themselves primarily to keep up appearances, insects groom for survival, according to a new study. A team of researchers at North Carolina State University and the Russian Academy of Sciences has determined that a number of bugs, including the American cockroach, habitually clean their antennae to remove chemical residues that build up there (Proc. Natl. Acad. Sci. USA, DOI: 10.1073/pnas.1212466110). Insects use sensors on their antennae to find food and mates, as well as to avoid danger, and these findings “explain why they fastidiously groom, even in clean places,” says team leader Coby Schal, an entomologist at NC State. Using nerve cell recordings, the researchers showed that when cockroaches aren’t allowed to groom their antennae the insects can’t detect food odors such as geranyl acetate and sex pheromones such as periplanone-B with their usual sensitivity. Gas chromatography analysis unveiled that waxy long-chain alkyl compounds known as cuticular hydrocarbons are the main substance that accumulates on the ungroomed antennae. Insects secrete these chemicals as a protective coating to prevent dehydration and pathogen invasion. “Given the findings,” says biologist Susan M. Bertram of Canada’s Carleton University, “future research could explore insecticides that prevent grooming and thus constrain fitness in pest insects.”

 
Chemical & Engineering News
ISSN 0009-2347
Copyright © American Chemical Society