Phylogenetic position of the ant genus Acropyga Roger (Hymenoptera: Formicidae) and the evolution of trophophoresy.

Trophophoresy is exhibited in two ant genera: Acropyga (Formicinae), in which all 37 species are thought to be trophophoretic, and Tetraponera (Pseudomyrmecinae), in which it has been observed in only one species, T. binghami. This study analyses a dataset comprised of both morphological and molecular (D2 region of 28S rRNA and EF1-alpha) data. Evidence is presented in favor of Acropyga being monophyletic, hence trophophoresy has evolved only once within the Formicinae and twice within the ants overall. The data further suggests that Acropyga belongs within a clade containing Anoplolepis, Aphomomyrmex, and Petalomyrmex. Aphomomyrmex and Petalomyrmex were found to be the sister group to Acropyga. The results indicate that the Lasiini and Plagiolepidini are not monophyletic and are in need of reexamination. Given the extant pantropical distribution of Acropyga it is speculated that Acropyga maybe of Gondwanan origin and that trophobiosis was the first form of agriculture to evolve in the ants.