Meet Tetramorium immigrans.
I have never been more pleased to report a taxonomic name change than this one. Long called “Tetramorium caespitum”, then “Tetramorium species E” once it became clear the Eurasian T. caespitum was a complex of cryptic forms, the pavement ant has spread across the world and is now among most common urban ants in North America. After decades of confusion, Herbert Wagner has published a fine monograph on the taxonomy of the species complex. Among Wagner’s many discoveries was that Santschi’s 1927 “immigrans” was valid for this world-traveller. An apt change, and a fine resolution of a long-standing problem.
- Wagner, H.C. et al (2017). Light at the end of the tunnel: Integrative taxonomy delimits cryptic species in the Tetramorium caespitum complex (Hymenoptera: Formicidae)”. Myrmecological News 25: 95-129