Apparently of lowland forests, one series taken from a varzea habitat. Its morphology puts it within the rastrata group, and it is quite probably a millipede hunter.
A member of the banksi complex (in the banksi subgroup of the rastrata species group). Mandibles elongate and triangular, their basal 2/3 rugulose and a pical 1/3 smooth and shining; clypeal lamella medianly concave; scapes with no erect hairs; petiolar costulation mostly transverse, node broader than long; metacoxal teeth very slender, propodeal teeth short. Rarely collected, it is a close relative of Gnamptogenys laticephala. (Lattke 1995)
Keys including this Species
Distribution based on Regional Taxon Lists
Distribution based on AntMaps
Distribution based on AntWeb specimens
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Not much is known about the the biology of Gnamptogenys mediatrix. We can speculate that the biology of this species is similar to other species of the genus. Gnamptogenys are predatory ponerine ants that inhabit tropical and subtropical mesic forests. Nesting is typically at ground level in rotten wood or leaf litter. Some exceptions include species that are arboreal, a dry forest species and species that nests in sandy savannahs. Colony size tends to be, at most, in the hundreds. Queens are the reproductives in most species. Worker reproduction is known from a few species in Southeastern Asia. Generalist predation is the primary foraging/dietary strategy. Specialization on specific groups (millipedes, beetles, other ants) has developed in a few species.
The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.
- mediatrix. Gnamptogenys mediatrix Brown, 1958g: 326, fig. 15 (w.q.) BRAZIL.
- Brown, W. L., Jr. 1958g. Contributions toward a reclassification of the Formicidae. II. Tribe Ectatommini (Hymenoptera). Bull. Mus. Comp. Zool. 118: 173-362 PDF (page 326, fig. 15 worker, queen described)
- Lattke, J. E. 1995. Revision of the ant genus Gnamptogenys in the New World (Hymenoptera: Formicidae). J. Hym. Res. 4: 137-193
- Lattke, J.E., Fernández, F. & Palacio, E.E. 2007. Identification of the species of Gnamptogenys Roger in the Americas (pp. 254-270). In Snelling, R.R., Fisher, B.L. & Ward, P.S. (eds). Advances in ant systematics: homage to E.O. Wilson – 50 years of contributions. Memoirs of the American Entomological Institute 80: 690 pp. PDF