Reproductive strategy of the ponerine ant Gnamptogenys striatula Mayr (Hymenoptera : Formicidae)

The knowledge of the social structures of Ponerinae species helps to unders tand the evolution of sociality in ants in general because this subfamily i s often considered as ancestral. Gnamptogenys is among the most derived pon erine genera. We studied the reproductive strategy of Gnamptogenys striatul a by laboratory and field observations. The dimorphism between workers and queens was pronounced and the worker caste presented a monophasic allometry between head width and thorax width. Queenright and queenless colonies wer e both present in the field. The latter contained several gamergates wherea s queenright colonies had several functional queens and no mated worker. Th us, both types of colonies were polygynous, and queens seemed to impede the presence of gamergate. Reproductive workers from queenless colonies seemed to be selected among the individuals with the largest size and number of o varioles. Although we did not observe any behavioral dominance between quee ns, they did not lay eggs equally. This suggests a more subtle kind of hier archy. At the laboratory, isolated gamergates were able to found a colony i ndividually, like in many queenright ant species.