Lenomyrmex colwelli

This species is a montane endemic, known 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. (Longino 2006)

Identification
Longino (2006) - This is the first report of this recently described genus in Costa Rica (Fernández and Palacio 1999, Fernández 2001). It is most similar to Lenomyrmex wardi, a species known from Ecuador. It differs in the much larger propodeal spines, the lack of a differentiated petiolar peduncle, and the smooth and polished postpetiolar dorsum.

Distribution based on Regional Taxon Lists
Neotropical Region: Costa Rica.

Nomenclature

 *  colwelli. Lenomyrmex colwelli Longino, 2006b: 135, figs. 8-10 (w.) COSTA RICA.

Worker
Holotype: ML 0.272, HL 0.740, HW 0.679, HC 0.601, SL 0.529, EL 0.199, MeL 1.050.

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.

Type Material
Holotype worker: Costa Rica: Heredia Prov., 16 km SSE La Virgen (10° 16' N, 84° 05' W), 1100 m elevation, 19. III.2001, leg. Project ALAS, specimen code INB0003211 842. Paratypes: 2 workers, same data as holotype, except 9.IV.2001, INB0003214454 ; and 20.II.2001, INB0003213510.

Etymology
Named for Robert K. Colwell, eminent tropical biologist, fellow Director of the ALAS Project, and long-term colleague and friend.

References based on Global Ant Biodiversity Informatics

 * Longino J. T. L., and M. G. Branstetter. 2018. The truncated bell: an enigmatic but pervasive elevational diversity pattern in Middle American ants. Ecography 41: 1-12.
 * Longino J. T., and R. K. Colwell. 2011. Density compensation, species composition, and richness of ants on a neotropical elevational gradient. Ecosphere 2(3): 16pp.