Trachymyrmex isthmicus Santschi 1931

Attini, Myrmicinae, Formicidae, Hymenoptera, Insecta, Arthropoda, Animalia

worker face view

worker lateral view


Ecuador, Colombia, Panama (type locality), Costa Rica. Costa Rica: Atlantic lowlands.


Preorbital carina sinuous or straight, extending past eye and directed toward posterolateral vertex margin; in face view with distinct lateral and posterolateral tubercles, such that margins of head behind eye are not rounded; anterior pair of mesonotal spines conical, stout; frontal lobes with anterolaterally projecting tooth.

Natural History

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.


Trachymyrmex isthmicus Santschi 1931:280-281, figs 13-15.


The species is fully described in MayhŽ-Nunez and Brand‹o (2007).

Literature Cited

MayhŽ-Nunes, A. J., and C. R. F. Brand‹o. 2007. Revisionary studies on the attine ant genus Trachymyrmex Forel. Part 3: The jamaicensis group (Hymenoptera: Formicidae). Zootaxa 1444:1-21.

Santschi, F. 1931. Fourmis de Cuba et de Panama. Revista de Entomologia (Rio de Janeiro) 1:265-282.

Weber, N. A. 1941. The biology of the fungus-growing ants. Part VII. The Barro Colorado Island, Canal Zone, species. Revista de Entomologia (Rio de Janeiro) 12:93-130.

Page author:

John T. Longino, The Evergreen State College, Olympia WA 98505

Date of this version: 7 May 2007.
Previous versions of this page: 5 January 2004
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