Gamergates (Mated Egg-Laying Workers) and Queens both Reproduce inEuponera sikoraeAnts from Madagascar

Abstract

Most ponerine ants have flying queens that monopolise sexual reproduction, but in a minority of species, workers can also mate and lay fertilised eggs. Such ‘gamergates' reproduce in addition to queens in some species but have replaced queens entirely in other species. The occurrence of a functional spermatheca in workers often appears associated with a slight difference in body size relative to winged queens, as is the case in Euponera sikorae (Forel) studied here. Eight colonies (19.9±8.7 workers and 0–2 dealate queens) were collected in humid forests of Madagascar. A mated queen reproduced in most colonies, but ovarian dissections indicated that 1–3 workers were also inseminated, and one of these laid eggs if the original founding queen was missing or no longer fecund. Exoskeleton remains (including 29 heads) of a staphylinid beetle were found in one nest of E. sikorae, pointing to specialised predation. We review the occurrence of non-flying reproductives (gamergates and ergatoid queens) in Odontomach...