The ant genus Tetraponera in the Afrotropical region: synopsis of species groups and revision of the T. ambigua-group (Hymenoptera: Formicidae)

The Afrotropical (including Malagasy) species of the ant genus Tetraponera F. SMITH, 1862 are evaluated, and five monophyletic species groups are established. A key is provided to these groups and their composition and distribution are summarized. One of these clades, the T. ambigua-group, is revised at the species level. Within this group the following new synonymies are proposed (senior synonyms listed first): T. ambigua (EMERY, 1895) = T. erythraea (EMERY, 1895) = T. bifoveolata (MAYR, 1895) = T. bifoveolata maculifrons (SANTSCHI, 1912) = T. ambigua rhodesiana (FOREL, 1913) = T. bifoveolata syriaca (WHEELER & MANN, 1916) = T. encephala (SANTSCHI, 1919) = T. ophthalmica angolensis SANTSCHI, 1930 = T. ambigua occidentalis MENOZZI, 1934; and T. ophthalmica (EMERY, 1912) = T. ophthalmica tenebrosa SANTSCHI, 1928 = T. ophthalmica unidens SANTSCHI, 1928 = T. nasuta BERNARD, 1953. This reduces the number of valid species to two, T. ambigua and T. ophthalmica, both widely distributed on the African continent. Two additional species are described: T. parops sp.n., from east Africa and T. phragmotica sp.n., from northwestern Madagascar. All four species in the T. ambigua-group have a dimorphic worker caste, a trait otherwise unknown in the subfamily Pseudomyrmecinae. The major workers and queens of T. phragmotica sp.n. have plugshaped heads, which are remarkably convergent with those of distantly related ant species in the formicine tribe Camponotini. The phylogeny and biogeographic history of the T. ambigua-group are briefly discussed.