Polistes dominulus (Hymenoptera: Vespidae) larvae have their own chemical signatures

Social insects use cuticular hydrocarbons (CHCs) as recognition cues in a variety of social contexts, such as species and nestmate recognition. Discrimination of nestmates is an important requisite to avoid exploitation by unrelated individuals. In social wasps, use of CHCs in nestmate recognition has been demonstrated only among adults, whereas very little is known regarding brood recognition. We performed gas chromatography-mass spectrometry analyses of the CHCs of adults and larvae of the social wasp Polistes dominulus and found that larvae possess a characteristic chemical colony-specific pattern distinct from that of adults. Behavioural assays confirmed that these are recognized and discriminated by adults. Larval epicuticular substances are therefore sufficient for recognition of nestmate larvae by adults and demonstrate that wasps are able to discriminate between alien and nestmate larval odours.