Yet another rediscovery. It gets too familiar after a while, but it does demonstrate how little is known about the ants of Africa.
Monomorium vonatu was known only from a single holotype specimen in the Natural History Museum, London. It was collected in 1970 in Ghana and described by Bolton (1987). It is easily distinguished from other species of Monomorium by the shape of the petiole and postpetiole, which both have distinct ridges running across them. The only other species that has this structure is Monomorium mirandum, which is very distinctly bicoloured.
As if to demonstrate that you don't need to go to great lengths to find interesting species, I collected my M. vonatu specimens in the grounds of the hotel we were staying in. They were found on the ground, either in bare sand or grassy areas.
Quite why this species hasn't been discovered anywhere else seems a bit of a mystery, as it was probably pretty common in suburban Kololi. Perhaps it is overlooked as another small black species of Monomorium.
These have been compared the holotype at the Natural History Museum, London, and are confirmed as M. vonatu.