Notes on female and worker survivorship in the archaic ant genus myrmecia

Abstract

Female and worker survivorship records are presented for several species of the archaic ant genusMyrmecia and are compared with some unpublished data of the authors for three genera of Ponerines and with values in the literature for certain higher ants. The evidence seems good that, even at the primitive grade of social development ofMyrmecia, survivorship capacities of fertilized brood females are comparable with those of many higher ants. The Ponerine, Formicine, and Myrmicine species with which comparisons are made are all, with the exceptions ofMonomorium pharaonis andMyrmica sabuleti, primarily monogynous and with possible minor exceptions found their colonies haplometrically. This is also true of the species ofMyrmecia considered, but colony-founding females ofMyrmecia and of the Ponerine species addressed typically establish their colonies partially rather than entirely claustrally. These survivorship patterns are in strong contrast to those recorded in the literature for both queens and workers of the highly opportunistic advanced Myrmicine speciesMonomorium pharaonis. The very short life-spans for queens and workers of this species, apparently adaptive to its peculiar and highly evolved life style, indicated, interestingly, a queen/worker survivorship ratio generally similar to that ofMyrmecia. Evidently the relatively long survivorship ofMyrmecia is consonant with that in many more advanced ants, but contrasts sharply with the very limited life-length characteristic ofMonomorium females and workers. It would be interesting to investigate this situation in other ants of life-style generally similar to that ofM. pharaonis.