A Revision of the Ant Genus Rhytidoponera (Hymenoptera: Formicidae) in New Caledonia

Abstract

In this revision of the genus Rhytidoponera on the island of New Caledonia, 18 species are recognized: seven previously described taxa (acanthoponeroides Viehmeyer, atropurpurea Emery, fulgens Emery, numeensis Andre, pulchella Emery, versicolor Brown, and wilsoni Brown) and 11 new species (aquila sp.nov., arborea sp.nov., depilis sp.nov., insularis sp.nov., koumensis sp.nov., litoralis sp.nov., luteipes sp.nov., mimica sp.nov., nitidiventris sp.nov., opaciventris sp.nov., and terrestris sp.nov.). All of these species are endemic (except perhaps terrestris, for which there is a questionable record from Vanuatu), and they segregate into four species-groups: acanthoponeroides group (one species), fulgens group (four species), numeensis group (three species) and pulchella group (ten species). Alate queens have not been found in any species, suggesting that colonies are entirely worker-reproductive. The behaviour and nest architecture of species in the pulchella group indicates specialization as foliage-foragers on understorey and forest edge vegetation, in contrast to the ground-foraging tendencies of the remaining species. Some pulchella-group species are involved in mimicry complexes with other ants and other foliage- frequenting arthropods. Closely related species of New Caledonian Rhytidoponera are usually distributed allopatrically, and conspecific populations exhibit a wide range of morphological differentiation.