Trachymyrmex cornetzi (Forel 1912)

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

worker face view

worker lateral view


Panama, Costa Rica, Colombia (type locality), Trinidad, Guianas. Costa Rica: widespread below 500m.


Preorbital carina curved inward, arcing obliquely toward frontal carina; propodeal spines short, not or barely differentiated from other tubercles on dorsal face of propodeum; scapes slightly surpassing vertex margin; frontal lobes strongly angulate.

Similar species: bugnioni.

Natural History

Trachymyrmex cornetzi inhabits wet and dry forest habitats. It seems to prefer relatively open areas with a thin litter layer. Nests are in the soil.

This species is relatively common at La Selva Biological Station. Nests have been excavated by attine specialists in the laboratory clearing, it has been collected at honey/crisco baits in the forest, and the ALAS project has collected it in Winkler and Berlese samples.

One nest I excavated at La Selva was 10cm deep, with a 4cm diameter spherical chamber containing a fungus garden. The nest entrance was completely unadorned and led straight down to the chamber. The nest was collected on 1 July 1992 and contained abundant alate queens and a few adult males.

Another nest I excavated was in Manuel Antonio National Park. A nest was in clay soil in the middle of a trail. There was an asymmetrical pile of soil at the nest entrance, and a 3-4cm diameter fungus nest in a chamber about 5cm deep. A small Mycocepurus nest, with a small turret of clay soil, was within 5cm of the nest entrance of the Trachymyrmex.

I have also collected the species as ground foragers in Corcovado and Santa Rosa National Parks.


Atta (Trachymyrmex) cornetzi Forel 1912:183. Worker, queen: Colombia. Combination in Trachymyrmex: Gallardo, 1916:242. Senior synonym of annulatus, bivittatus, brevispinosus, gatun, naranjo and uncifer: Weber, 1958:49.


This species is similar to bugnioni. The two species are sympatric in the northwestern lowlands of Costa Rica.

Jeffry Sossa examined the types of T. cornetzi and T. intermedius, and kindly pointed out that my morphospecies JTL-001 was actually T. cornetzi, and what I had been calling T. cornetzi before was actually T. intermedius. I have fixed those errors with this version of the page.

Page author:

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

Date of this version: 1 March 2007.
Previous versions of this page: 5 January 2004.
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