Sitting around? (Chomp!) Back to work!

When a wasp bites nestmates, is it sending a message that translates roughly as “Stop goofing around and do some work”?

That possibility occurred to Sean O’Donnell at the University of Washington in Seattle when he studied one of the so-called eusocial wasps, Polybia occidentalis. This tropical species builds colonies of several hundred wasps that share life’s tasks much as bees do. As they age, the female worker wasps switch jobs, starting as indoor nursemaids and ending up as food gatherers.

While watching P. occidentalis colonies, O’Donnell often saw one worker bite a nestmate. The encounters ranged from a mild nip to forceful attacks in which the biter grabbed and shook a nestmate.

Could these attacks indicate some conflict over egg-laying rights? O’Donnell mused at first. That’s a classic conflict for truly social insects, which form colonies of female workers tending queens that lay the eggs. However, O’Donnell didn’t find a connection between reproduction and the biting. Neither the wasps that do the biting nor those that get bitten have working ovaries, he reports in the May Behavioral Ecology.

O’Donnell did note a tendency for wasps on the receiving end of a chomp to start some task soon afterward. In particular, he found that such wasps often would leave the nest on foraging missions. O’Donnell hypothesizes that biting may turn out to be a way that social insects manage their colonies.

Susan Milius is the life sciences writer, covering organismal biology and evolution, and has a special passion for plants, fungi and invertebrates. She studied biology and English literature.