The Tetramorium tortuosum species group (Hymenoptera, Formicidae, Myrmicinae) revisited - taxonomic revision of the Afrotropical T. capillosum species complex.

In this study we revise the taxonomy of the Tetramorium tortuosum species group members encountered in the Afrotropical region, which we have placed in its own subgroup: the Tetramorium capillosum species complex. We re-describe the two previously known species Tetramorium capillosum Bolton and Tetramorium tabarum Bolton, and describe the new species Tetramorium hecate sp. n. The geographic distribution of the three species appears to be restricted to the equatorial rainforests of Central Africa. We provide a diagnosis of the Tetramorium capillosum species complex, an illustrated identification key to species level, and worker-based species descriptions, which include diagnoses, discussions, high-quality montage images, and distribution maps. Furthermore, we discuss biogeography and composition of the globally distributed Tetramorium tortuosum group.