QUEEN AND COLONY ODOR IN THE MULTIPLE NEST ANT SPECIES, CATAGLYPHIS-IBERICA (HYMENOPTERA, FORMICIDAE)

We investigated the queen's effect on the cuticular hydrocarbon profil e of workers in the monogynous and polydomous species Cataglyphis iber ica. Within each of the three colonies tested, workers were separated for three months in queenright and queenless groups. After regrouping, nestmate recognition remained unchanged but the duration of antennal interactions between workers previously separated increased relative t o controls. Separated groups presented slightly divergent cuticular hy drocarbon profiles which may induce the longer antennations. A quantit ative analysis of major cuticular hydrocarbons showed that the total a mount per unit of cuticular surface area remains similar between the t wo castes; but queens had higher quantities of n-alkanes than workers. The lack of a queen did not affect the workers' cuticular hydrocarbon profile in queenless groups. Indeed, the profile of queenless workers remained significantly different from the queen profile as did that o f queenright workers. These results show that queens are not at the or igin of the hydrocarbons' colonial profile. Two recognition processes seem to coexist within C. iberica colonies: nestmate discrimination ba sed on the colonial odour which includes all nestmate workers, and a q ueen caste-specific odour. In a polydomous species such as C. iberica, the queen does not seem to contribute more than any other nestmate to the colonial odour, which probably derives from worker cues, confirmi ng the existence of a ''Gestalt'' colonial odour.