Wily wasps ferment ant civil war

Insects that parasitize social insects are extreme specialists and have developed highly specific mimicry or stealth mechanisms to exploit this niche. In 30 May Nature, Jeremy Thomas and colleagues from Centre for Ecology and Hydrology, Dorchester, UK, show how secretions from the parasitoid wasp Ichneumon eumerus induces in colony fighting in Myrmica schencki ants, enabling it to sneak in and parasitize caterpillars of the social parasite Maculinea rebeli (Nature 2002, 417:505)

Thomas et al. tested the effect of M. rebeli pupal cases from which the wasps had already emerged on ant colonies. Both the empty cases and dummies to which a solvent wash from the cases had been applied induced fierce fighting in the M. schencki ants, whereas cases that had been washed in the solvent produced no reaction.

Analysis of the solvent by gas chromatography with mass spectrophotometry identified thee alcohols and three aldehydes; four of which are new ...