Journal Article (Refereed)
Chemical basis of nestmate recognition in the ant Formica exsecta
Martin, S 2008, 'Chemical basis of nestmate recognition in the ant Formica exsecta', Proceedings of the Royal Society B.
Distinguishing nestmates from non-nestmates underlies key animal behaviours, such as territoriality, altruism and the evolution of sociality. Despite its importance there is very little empirical support for such a mechanism in nature. Here we provide data that the nestmate-recognition mechanism in an ant is based on a colony-specific Z9-alkene signature, proving that surface chemicals are indeed used in ant nest-mate recognition as was suggested 100 years ago. We investigated the cuticular hydrocarbon profiles of ten Formica exsecta colonies that are composed almost entirely of a Z9-alkene and alkane component. Then we showed that worker aggression is only elicited by the Z9-alkene part. This was confirmed using synthetic Z9-alkene and alkane blends matched to the individual colony profiles of the two most chemical different colonies. In both colonies only glass beads with ‘nestmate’ alkene profiles received reduced aggression. Finally, changing the abundance of a single Z9-alkene on live ants was shown to significantly increase the aggression they received from nestmates in all five colonies tested. Our data suggest that nestmate discrimination in the social insects has evolved to rely upon highly-sensitive responses to relatively few compounds.
Proceedings of the Royal Society B