Ants of Uluapan

Ants of Uluapan, Oaxaca, Mexico

Report by John T. Longino, Michael G. Branstetter, The University of Utah; Jorge Valenzuela, Instituto de Ecología, Xalapa, Mexico. Student participants: Mario Augillar Mendez (Guanajuato), Brianna Bartholomew (Univ. Utah), Rhea Cone (Univ. Utah), Erika Alejandra Conti González (Guanajuato), Miguel Angel García-Martínez (INECOL), Kyle Gray (UC Davis), Dennis Infante (INECOL), Anamin Saraí Lizama Ramírez (Guanajuato), Jaqueline Ochoa Vega (Guanajuato), Madai Rosas Mejía (Guanajuato), Gabriel Somarriba (Univ. Florida).

This is a list of the ants of Uluapan, Mexico, based on Project ADMAC sampling. Uluapan is a site in the state of Oaxaca, at the base of a massive limestone escarpment, Cerro Rabón, in the Sierra Mazateca. The escarpment extends from around 300m elevation at the base to over 2000m at the top. Uluapan is a patch of rainforest that surrounds a large spring that emerges from the base.

Project ADMAC carried out ant sampling at Uluapan from 9-16 June 2016. Sampling included two miniWinkler transects of 50 samples each (5 m spacing; red dots), maxiWinkler samples (yellow dots), baiting transects (20 baits each, blue dots), beating samples (2hrs, green dots), and Malaise traps (white dots). Most sampling was from about 350-550m, but a few maxiWinkler samples were taken along a steep trail above the spring, the highest sample being 845m. Those uppermost maxiWinkler samples were in an area that was beginning to have some cloud forest characteristics, and the ant fauna was somewhat different from the lower samples.

Specimen records have been uploaded to the AntWeb database and are periodically updated. Names in the species list are linked to individual specimen records on AntWeb, from which a link can be followed to the general species page. These specimens function as site-specific vouchers, whose identities may change. The species names in the list are static text on this page. Following the specimen link to AntWeb will allow one to see if the name has changed.

Pseudomyrmex identifications were provided by Phil Ward.

There are at least 172 species.

Several notable discoveries were made:

A new Crematogaster is close to C. nigropilosa, a widespread species in Central America.

A distinctive new Fulakora species was collected as a series of winged queens in a Malaise trap. A specimen of the rare F. degenerata was also found.

Myrmecina harrisoni represents a range extension of this poorly-known Mexican species of a Nearctic lineage. Previously this species was only known from Rancho Cielo in Tamaulipas, Mexico. This is the southernmost record of Myrmecina in the Americas.

This site revealed sympatry of two species that both key to the widespread Pachycondyla harpax, differing in size.

As usual, a substantial Pheidole community was present. An interesting find was multiple specimens of a diminutive Pheidole queen that is almost certainly a workerless social parasite. Unfortunately they were all found in Winkler samples, not in nests.

The most remarkable find of all was what appears to be a truly cavernicolous ant. We found a highly aberrant, new species of Stenamma, foraging 30m deep in a limestone cavern.