Reproduction and division of labour in Leptogenys schwabi Forel (Hymenoptera Formicidae), a polygynous, queenless ponerine ant

The combination of polygyny and natural queenlessness is uncommon in ants. The ponerine ant Leptogenys schwabi Forel 1913 has no morphologically or anatomically distinct reproductive castes and several mated workers in each colony, providing a model for the study of the effect(s) of polygyny on the social organization of a naturally queenless species of ponerine ant. L. schwabi also presents a case of queenlessness that is useful in comparative evolutionary studies of natural queenlessness because it is phylogenetically independent of previously- studied examples.Virgin laying workers were few unless mated workers were experimentally removed from the colony, indicating that their reproductive physiology is regulated by the mated workers. No physical interactions or oophagy were seen, implicating a pheromonal mechanism of regulation. The combination of queenlessness and polygyny did not affect the general pattern of division of labour. This may be attributed to the inhibitory influence exerted by mated workers over virgin workers that forestalls the disruptive effects of reproductive competition among virgin workers.