When wasps sporting the high-quality symbol of a blotchy face turned out to be wimps, they got harassed more than wasps whose abilities were honestly reflected by their faces, report researchers.
It's the first conclusive report that animals that don't signal their qualities honestly receive social sanctions. Moreover, it's the first report of such quality signals in insects.
"It's the most conclusive evidence that these dishonest visual signals have a social cost," said Elizabeth A. Tibbetts, a postdoctoral fellow with the Center for Insect Science at the University of Arizona in Tucson. "If you fake it, you'll get beaten up."
She and her co-author James Dale of Simon Fraser University in Burnaby, British Columbia, Canada report their findings in the Nov. 11 issue of the journal Nature.
Many animals sport visible indicators of the bearer's quality. Such signals include the redness of a cardinal or the size of the black spot on a house sparrow's chest.
However, biologists wonder what keeps other animals from cheating by displaying a mark that indicates "I'm great" while actually being just average. Scientists hypothesize that social interactions discourage cheating, but demonstrations of such interactions have been elusive.
Tibbetts noticed that for wasps in the species Polistes dominulus, the facial markings varied among individuals. Because these wasps are social insects that form multi-queen nests, she wondered whether the markings had significance to the wasps.
Researchers already knew that in such nests, the wasps establish a dominance hierarchy by fighting. The winner, the top or alpha wasp, gets to lay more eggs and do less work than the other wasps. To see whether they could detect what signaled an alpha wasp, Tibbetts and Dale decided to stage wasp fights.