Chemical basis of nest-mate discrimination in the ant Formica exsecta.
Distinguishing nest-mates from non-nest-mates 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 nest-mate 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 10 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 different chemical colonies. In both colonies, only glass beads with 'nest-mate' 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 nest-mates in all five colonies tested. Our data suggest that nest-mate discrimination in the social insects has evolved to rely upon highly sensitive responses to relatively few compounds.
Martin
Stephen J
SJ
Laboratory of Apiculture and Social Insects, Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK. s.j.martin@sheffield.ac.uk
Vitikainen
Emma
E
Helanterä
Heikki
H
Drijfhout
Falko P
FP
D000374:Aggression / Q000187:drug effects / Q000502:physiology; D000473:Alkanes / Q000737:chemistry / Q000378:metabolism; D000475:Alkenes / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D000819:Animal Communication; D000818:Animals; D001000:Ants / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D001522:Behavior, Animal / Q000187:drug effects / Q000502:physiology*; D012919:Social Behavior
D000473:Alkanes; D000475:Alkenes