This is a cosmopolitan genus of small predacious ants, nesting in soil and rotten wood. Four species are known from California, of which one ( Hypoponera sp. CA-01) is apparently undescribed and not included in the keys cited below. It is similar to Hypoponera opacior (Forel) from which it can be distinguished by the orange-brown body color (usually dark brown in California H. opacior ), narrower head (CI 0.77-0.83, as opposed to 0.83-0.87 in H. opacior ), and conspicuous standing pilosity on the venter of the head (such pilosity sparse in California populations of H. opacior ).
Species identification: keys in Creighton (1950a), Wheeler and Wheeler (1986g) and Mackay and Mackay (2002). Additional references: Delabie and Blard (2002), Duffield et al. (1976), Foitzik et al. (2002), Taylor (1967a).