One of the more common ants in eastern North America is, ostensibly, Dolichoderus. I’ve read that, while restricted to particular habitat types, within those bogs and pine forests they are supposed to be abundant. In theory.
Yet in my entire decades-long career as an ant guy, I have never once seen them alive in North America. Anywhere. It got to the point where I was embarassed to admit such a glaring failure.
Anyway. I broke down and finally begged Ant Guru James Trager to send me a few live workers, and James kindly took pity on me. Herewith, at last, photographs of our North American Dolichoderus:
Dolichoderus mariae – Peninsula State Park, Wisconsin, USA.
A grooming Dolichoderus plagiatus worker shows the protruding propodeum that is diagnostic for the North American species of this genus. Baileys Harbor Beach, Wisconsin, USA.
Dolichoderus plagiatus – Baileys Harbor Beach, Wisconsin, USA.
No longer fighting over a name.
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.