FUNCTIONAL SUBCASTE DISCRIMINATION (FORAGERS AND BROOD-TENDERS) IN THE ANT CAMPONOTUS-VAGUS SCOP - POLYMORPHISM OF CUTICULAR HYDROCARBON PATTERNS

In the ant Camponotus vagus, when selected foragers that had been earl ier removed from the foraging arena and brood-tenders that had been ea rlier removed from the nest were placed together in a foraging arena, most of the brood-tenders and only a few of the selected foragers were carried back to the nest by nonselected foragers. We hypothesize that cuticular hydrocarbons serve as a cue that allows foragers to discrim inate between members of their own subcaste and brood-tenders. It has been established that the proportions of certain hydrocarbons, which a re the same regardless of the colony studied, vary from one worker sub caste to another and thus constitute a specific chemical signature. Th ese hydrocarbons belong to a wide range of chemical families (alkanes, monomethylalkanes, and dimethylalkanes). The greatest differences bet ween the two subcastes were observed on the thorax of workers. Princip al component analyses performed on the hydrocarbons (or hydrocarbon co mbinations) corresponding to the 45 main peaks in the cuticular profil es of the head and thorax of brood-tenders and foragers of several col onies show that there exist quantitative differences between the vario us signatures that characterize the colony, the worker subcastes, and the various body parts within the same species, which can be classifie d in a hierarchy where the differences between worker subcastes are le ss pronounced than those between body pans or between colonies.