Four species within the supercolonial ants of the Tapinoma nigerrimum complex revealed by integrative taxonomy. Cryptic species in the ant Tapinoma nigerrimum

The West and Central Mediterranean ants known for 50 years under the name Tapinoma nigerrimum (Nylander, 1856) have attracted attention because of their efficient chemical weapons, impressive supercolonies and potential to limit the spread of the Argentine Ant Linepithema humile (Mayr, 1866). The study shows that the T. nigerrimum complex consists of four clearly separable species which differ in morphology of all castes, colony demography, geographic distribution, invasive potential and mtDNA data. Species delimitation by means of Nest Centroid Clustering, considering 20 quantitative characters in 159 nest samples, resolved four coincident clusters in both females and males which are classified as T. nigerrimum, T. magnum Mayr, 1861, T. ibericum Santschi, 1925 and T. darioi sp. nov.