Social closure, aggressive behavior, and cuticular hydrocarbon profiles in the polydomous ant Cataglyphis iberica (Hymenoptera, Formicidae)

Nestmate recognition was studied in the polydomous ant Cataglyphis iberica (Formicinae) in the laboratory. The study examined six colonies collected from two different populations 600 km apart in the Iberian peninsula (Barcelona and Murcia). Introduction of an alien worker into an allocolonial arena always ended in death to the intruder, demonstrating that in this species societies are extremely closed. Dyadic encounters composed of individuals from different colonies in a neutral arena confirmed the existence of high aggression between allocolonial individuals. We also investigated variability in the composition of the major cuticular hydrocarbons between the colonies used in the behaviorial tests. There were marked quantitative differences between the profiles of ants from the two populations, suggesting that the populations are completely segregated. Cuticular profiles within a population tended to be more similar, but were nevertheless colony specific. The degree of colony closure in C. iberica seemed to be independent of geographic distance since aggression between the colonies was always at its maximum, irrespective of their population origin.