Intricacies of the Biology of Dolichoderus quadripunctatus (L.) (Hymenoptera: Formicidae)

Abstract. The arboreal monogynous ant Dolichoderus quadripunctatus (L.) usually nests in very confined loci, and the colony consists of several to many nests, of which one or a few are queenright. Sexual offspring develop in queenless nests, though males and gynes in separate nests. The prevailing view of the colony dynamics maintains that males invade nests with gynes to mate there. New queenright nests are thought to develop such that a gyne remains in her natal nest or gynes are carried by workers to an offshoot nest without a queen. In our previous, two-season studies we could not find support for these claims, and the present, third-season observations corroborate our previous results: gynes leaving their nest either by flight or on foot are mainly unmated. It is not known how and where a gyne settles down and how a new queenright nest or a new colony originates. The peculiar habit of alate gynes to walk along worker trails, although not reported in other studies, is a regular feature of the colonies studied by us in Poland. We suggest that its function is close-range dispersal, which in a network of intersecting trails belonging to different colonies might allow the gyne to cross colony boundaries. Mating and reproducing outside own natal colony would enhance outbreeding in a species inherently exposed to inbreeding. Long-range dispersal by flight would effectively lead to outbreeding, given that the gyne succeeds to mate and found a colony. This topic is still unstudied, and it seems that a deeper understanding of the colony dynamics and dispersal of D. quadripunctatus requires population-genetic studies of carefully mapped colonies.