Gnamptogenys tornata (Roger 1861)

Proposed revised status; currently a junior synonym of sulcata (Smith).

Formicidae, Hymenoptera, Insecta, Arthropoda, Animalia

worker face view

worker lateral view

Range

Southern Mexico to Colombia (Brown 1958). Costa Rica: widespread in wet forest to 1200m.

Identification

Promesonotal suture absent; scapes surpass margin of vertex when laid back; mandibles smoothly curving such that basal and apical margins form a continuous convexity; head yellowish to brown in color; mandibles dull yellow to brownish, usually lighter than cranial color, but not markedly contrasting with it; head and rest of body nearly concolorous; costulae often transverse across posterior face of propodeum; eyes relatively small (eye length = 0.25, width = 0.18, n=1 worker).

Natural History

This species inhabits lowland rainforest. It occurs in samples of sifted leaf litter from the forest floor, and has been observed nesting in a hollow stick in the leaf litter. The nest contained aradid bugs as prey. Colonies can be polygynous.

Selected Costa Rican records:

Cartago: 7km ESE Moravia, 948'N, 8323'W, 1150m (J. Longino). Trailside second growth veg., surrounded by primary wet forest; worker and dealate queen in general collection.

Guanacaste: Estacion Pitilla, Guanacaste Conservation Area, 1059'N, 8526'W, 700m (J. Longino). Wet forest. (1) Ex sifted leaf litter from forest floor (Winkler sample). (2) Under loose bark in treefall.

Heredia: 22km N Volcan Barba, 1020'N, 8404'W, 500m (J. Longino). Mature wet forest. Colony in hollow stick in leaf litter. Remains of two dead aradids, other aradid fragments were inside. Nest contained at least 4 dealate queens.

Puntarenas: 19km S Ciudad Neily, 829'N, 8258'W, 20m (J. Longino). Mature wet forest. Ex sifted leaf litter from forest floor (Winkler sample).

Puntarenas: Sirena, Corcovado National Park, 829'N, 8336'W, 5m (J. Longino). Lowland wet forest; running on ground.

Puntarenas: Wilson Botanical Garden, 4km S San Vito, 847'N, 8258'W, 1200m (J. Longino). Wet forest; ex sifted leaf litter from forest floor (Winkler sample).

San Jose: Carrillo, Braulio Carrillo National Park, 1009'N, 8355'W, 500m (J. Longino).

Taxonomic Notes

Brown (1958) treated sulcata and tornata as distinct, based on the same characters used here, but speculated that they could turn out to be variants of one plastic species. Lattke (1995) supported the latter position, treating sulcata and tornata as synonyms because over the full range of the complex there are intermediate forms. For example, he stated "Color is of no help in separating the ... forms, except at an occasional local level" (italics mine). Color and other characters separate the two forms at the local level in Costa Rica, where they appear to be distinct and broadly sympatric. I feel that species have their greatest objectivity at the local level, and follow Gentry (1990) in giving locally defined species primacy.

Type data

Ponera tornata Roger 1861:15. Syntype worker, queen, male: Mexico, Veracruz.

Literature Cited

Brown, W. L., Jr. 1958. Contributions toward a reclassification of the Formicidae. II. Tribe Ectatommini (Hymenoptera). Bulletin of the Museum of Comparative Zoology 118:175-362.

Gentry, A. H. 1990. Herbarium taxonomy versus field knowledge; is there an attainable solution? Flora Malesiana Bulletin Special Volume 1:31-35.

Lattke, J. E. 1995. Revision of the ant genus Gnamptogenys in the New World (Hymenoptera: Formicidae). Journal of Hymenoptera Research 4:137-193.

Roger, J. 1861. Die Ponera-artigen Ameisen. Berliner entomologische Zeitschrift 5:1-54.


Page author:

John T. Longino, The Evergreen State College, Olympia WA 98505 USA.longinoj@evergreen.edu


Date of this version: 6 December 1998
Previous versions of this page:
Go back to top

Go to Ants of Costa Rica Homepage