Worker: mandible smooth and shining; eye with about 9 ommatidia across greatest diameter; face with dense foveate sculpture grading to reticulate rugose sculpture toward vertex; mesosoma covered with coarse, widely-separated rugae, shiny interspaces, rugae transverse on promesonotal dorsum and dorsal face of propodeum, curving to longitudinal on side of pronotum, mesopleuron, and side of propodeum, posterior face of propodeum with fine transverse rugulae; propodeal spines long, stout; inferior propodeal lobes broadly triangular; petiole gradually sloping to rounded posterior node, without differentiated peduncle; petiole with large, sharp anteroventral tooth; petiolar dorsum with faint longitudinal rugulae anteriorly, grading to smooth and shining posteriorly; dorsum of postpetiole and entire gaster smooth and shining, highly polished; scape with about 10 fine erect setae that are about half maximum width of scape; face, promesonotal dorsum, posterior petiolar dorsum, postpetiolar dorsum, and gastral dorsum with similar sparse, short, erect setae; scapes, face, and side of head with sparse, long, appressed pubescence; tibia with very sparse short appressed pubescence, a few erect setae at apex near basitarsus; surface of gaster with no pubescence; mandible and tip of funiculus yellow brown, scapes and legs including coxae light red brown, rest of body dark red brown.
Measurements (holotype): ML 0.272, HL 0.740, HW 0.679, HC 0.601, SL 0.529, EL 0.199, MeL 1.050.
Etymology:
Named for Robert K. Colwell, eminent tropical biologist, fellow Director of the ALAS Project, and long-term colleague and friend.
Natural History:
This species is a montane endemic, known only from one cloud forest site on the Barva Transect in Braulio Carrillo National Park. It is known only from the type specimens, which occurred in two miniWinkler samples (leaf litter sifted from a 1 m2 forest floor patch) from two of the Project ALAS Winkler transects and one Berlese sample of rotten wood (http://purl.oclc.org/alas).
Costa Rica (Cordillera Volcanica Central).
