Social Structure and Reproductive Systems of Tramp Versus Endemic Ants (Hymenoptera: Formicidae) of the Ryukyu Islands

Abstract

Currently, 126 ant species have been recorded from the Ryukyu Islands, Japan. Of these, 54 species, many of which are probably new to science, have not yet been identified. A survey on species-habitat relationships made on the island of Okinawa indicated that open lands were occupied predominantly by tramp species, but primary forests contained many endemic species. Colony structure and the reproductive system of the eurychoric species are briefly reviewed and discussed. A secondary polygynous and polydomous system is predominant in these species. This system is characterized by intranidal mating, which may reduce the risk in nuptial flights and ensure the adoption of new queens. A diversity in morphology and behavior, especially in males, seems to develop, provided the workers care for them. Stenochoric forest species are mostly monogynous.