ALATE GYNES OF DOLICHODERUS QUADRIPUNCTATUS (L.) (HYMENOPTERA: FORMICIDAE) ON FORAGING TRAILS - A PECULIAR WAY OF DISPERSAL

We describe the behaviour of Dolichoderus quadripunctatus (L.), an oligogyne ant species, during baiting experiments. Numerous alate gynes (mostly unmated) walked along foraging trails of conspeeific workers, but only occasionally a gyne licked the carbohydrate food regularly consumed by the workers. Based on the behaviour of these gynes and previous knowledge of the structure of the foraging trails of D. quadripunctatus within polydomous colonies, the structure and social organisation of these colonies, and the biology of the species, we suggest that gynes may use a previously undescribed means of dispersal. By not returning to her birth nest but walking along intersecting trails, an alate gyne may fortuitously find an auxiliary queenless nest and become adopted there. This behaviour adds to the dispersal tactics known or suggested earlier. We discuss these by evaluating the published data, and conclude that the spatial pattern of colonies have been described in detail, but the means of dispersal of D. quadripunctatus gynes and colony are still poorly documented. Plausible means have been proposed, some potentially leading to supercolonies covering large areas.