Lachnomyrmex grandis Fernandez and Baena 1997

Myrmicinae, Formicidae, Hymenoptera, Insecta, Arthropoda, Animalia

worker face view

worker lateral view

Additional images: worker dorsal view small, large; queen face view (small, large), lateral view (small, large).


Colombia (type locality), Costa Rica. Costa Rica: Atlantic slope to 500m elevation.


Worker: first gastral tergum with very long erect setae; metanotal groove broadly impressed; Weber's length about 1.0mm. Queen: Weber's length about 1.3mm.

Similar species: scrobiculatus, laticeps.

Natural History

I know this species from three collections:

Limon Province, Rio Toro Amarillo near Guapiles (W. L. Brown, Jr.). A worker and two queens.

Heredia Province, La Selva Biological Station (Project ALAS). A single worker from a Winkler sample from second growth forest.

Heredia Province, Barva transect in Braulio Carrillo National Park, 500m site (Project ALAS). A worker and queen from a miniWinkler sample.


This rare species looks like a very large version of scrobiculatus. On two of the collections the long setae occur on only the anterior third of the first gastral tergum, but on one collection they nearly cover the tergum.

ALAS staff member Nelci Oconitrillo was preparing and sorting Lachnomyrmex specimens from Winkler samples from La Selva, and she noticed one specimen that did not match any of the known species from La Selva. It was exciting to find that it matched exactly my notes on a collection from Rio Toro Amarillo (I have not directly compared these two collections).

It remains to be seen what makes this species so rare in collections. Is there some feature of its biology that makes it difficult to sample? Is it common in the environment but difficult to capture? Or is it truly low density?

Note of 12 April 2008: This was previously morphospecies JTL-004. Rodrigo Feitosa compared specimens with the types of L. grandis and said they were nearly identical.

See also revision by Feitosa and Brandčo (2008).

Literature Cited

Feitosa, R. M., and C. R. F. Brandčo. 2008. A taxonomic revision of the Neotropical myrmicine ant genus Lachnomyrmex Wheeler (Hymenoptera: Formicidae). Zootaxa 1890:1-49.

Page author:

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

Date of this version: 12 April 2008.
Previous versions of this page: 19 August 1998, 22 July 2005
Go back to top

Go to Ants of Costa Rica Homepage