Trachymyrmex isthmicus Santschi 1931:280-281, figs 13-15.
Weber (1941) observed a nest of the species on Barro Colorado, Panama. He described the nest entrance as a small turret, and he reported on a nest relocation.
I know this species only from the La Selva Biological Station and vicinity in the Atlantic lowlands. I found one nest in the soil at the edge of the CEN trail. The nest was a single chamber, about 10cm deep and about 5cm in diameter. A fungus garden filled the chamber and there was a single colony queen. The species has also been collected at honey/manteca baits and as isolated workers in Winkler samples.