Ants of Tapantí

Ants of Tapantí National Park, Costa Rica

Report by John T. Longino and Michael G. Branstetter, The University of Utah. Student participants: Irene Calderon, Josue Corrales, Krissy Dominguez, Scott Heacox, Josh Kouri, Irene Mata, Mac Pierce, Marianela Solís.

This is a list of the ants of Tapantí National Park, Costa Rica, based on Project ADMAC sampling.

Project ADMAC carried out ant sampling in Tapantí from 4-8 June 2015. We sampled along the main road through the park, within a few kilometers of the park entrance near Orosi. The habitat was dense, very wet, epiphyte-covered second growth cloud forest. Elevation of collecting sites varied from 1300m near the river to just under 1600m on the slopes. According to locals, the road through the park was a pre-Columbian trading route and was the main road to the south prior to the construction of the Panamerican highway. The slopes were deforested and owned by various farmers until declared a forest reserve in about 1975. It was declared a national park in 1992. Thus the forest is about 40 years old.

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.

There are at least 80 species. Notable discoveries include:

Eurhopalothrix JTL-025. This is a single specimen, from one of the miniWinkler transects, that does not match any known species. It is similar to the lowland species E. gravis but has a shinier gaster. It may be a new montane species related to E. gravis.

The large genus Pheidole had 23 species. The dominant species were cloud forest specialists that do not occur in the lowlands, but there was also a set of lowland species that were present at low density, apparently near the upper limit of their elevational range. An exciting discovery was a collection of P. laelaps, from a single bait card. This species was previously known from only two collections, from cloud forest sites in Colombia and Ecuador. The Costa Rican specimens differ in some details of pilosity and undoubtedly are a clade with some degree of divergence from their South American relatives. It was also rewarding to find P. picobarva, previously known only from the peak of Volcán Barva, north of San José.

The records of Myrmelachista joycei and Simopelta oculata are from 1988 collections by Longino; the species were not encountered during ADMAC sampling.