Multivariate discrimination of a new species of Tapinoma from the western United States

The ant Tapinoma sessile (Say) 1836 one of the most widely distributed ants in North America and yet has received very little attention from biologists apart from its ability to infest houses. The original species description does not adequately account for the phenotypic variation present in this species of typically concolorous and darkly colored ant. In California a bicolored morph was discovered that superficially resembles T. sessile, hence its species status was questioned. Comparative morphometric analysis indicates that these bicolored ants are consistently distinguishable across a range of characters and allometric techniques conclusively demonstrate that these two morphs are not the same species. Based on the analysis of morphological data it was concluded that the bicolored ant is not T. sessile and is described as a new species, Tapinoma schreiberi.