Role of cuticular hydrocarbons in the chemical recognition between ant species in the Pachycondyla villosa species complex

Chemical recognition of ants was studied at three levels of interactions (intra-colonial, intra-specific and inter-specific). Three closely related species already chemically characterized were used: Pachycondyla villosa (Pv), P. inversa (Pi) and P. subversa (Ps). Each species had its own behavioural responses. Moreover, responses of Pi and Ps towards Pv were significantly longer, than they were between themselves whereas Pv ants were equally aggressive towards Pi and Ps. These differences are in agreement with the results of the cluster analysis of the cuticular HCs profiles that place Pi closer to Ps. In support of the idea that components of cuticular lipids profiles are important for recognition, we found that only the HC fraction and its branched subfraction elicited a behavioural response of Ps workers. It is suggested that internally branched methyl- and dimethylalkanes are involved in recognition behaviour.