Pseudomyrmex osurus

Identification
Ward (1989) - Examination of the syntype worker of P. osurus shows this to be a distinct species, differing from Pseudomyrmex faber (F. Smith) by the shape of the petiole (possessing a distinct anterior peduncle and differentiated node, in lateral view), and the smooth, shiny puncticulate head. Enzmann 's description of P. insularis fits P. osurus tolerably well, and agrees more closely with P. osurus than with any other species in the P. laevigatus complex known to me from Central America.

P. osurus is typically concolorous orange (head black in some Costa Rican and Colombian workers, which I take to be this species), while P. faber is more variable, with some workers (including the type) having a dark brown to black head and mesosoma.

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

Nomenclature

 *  osurus. Pseudomyrma levigata subsp. osura Forel, 1911e: 279 (w.) COSTA RICA. Junior synonym of faber: Kempf, 1958f: 449. Combination in Pseudomyrmex: Ward, 1989: 441. Revived from synonymy, raised to species and senior synonym of insularis: Ward, 1989: 441.
 * insularis. Pseudomyrma laevigata subsp. insularis Enzmann, E.V. 1944: 88 (w.) PANAMA. Junior synonym of faber: Kempf, 1958f: 449; of osurus: Ward, 1989: 441.

Type Material
Syntype worker. Costa Rica (pittier) [Examined].

Pseudomyrma laevigata subsp. insularis Holotype worker, Barro Colorado Island, Panama (location unknown) [not examined].

References based on Global Ant Biodiversity Informatics

 * Brandao, C.R.F. 1991. Adendos ao catalogo abreviado das formigas da regiao neotropical (Hymenoptera: Formicidae). Rev. Bras. Entomol. 35: 319-412.
 * Enzmann E. V. 1944. Systematic notes on the genus Pseudomyrma. Psyche (Camb.) 51: 59-103.
 * Fernández F., E. E. Palacio, W. P. MacKay, and E. S. MacKay. 1996. Introducción al estudio de las hormigas (Hymenoptera: Formicidae) de Colombia. Pp. 349-412 in: Andrade M. G., G. Amat García, and F. Fernández. (eds.) 1996. Insectos de Colombia. Estudios escogidos. Bogotá: Academia Colombiana de Ciencias Exactas, Físicas y Naturales, 541 pp
 * Fernández F., and E. E. Palacio. 1995. Hormigas de Colombia IV: nuevos registros de géneros y especies. Caldasia 17: 587-596.
 * Fernández, F. and S. Sendoya. 2004. Lista de las hormigas neotropicales. Biota Colombiana Volume 5, Number 1.
 * INBio Collection (via Gbif)
 * Longino J. et al. ADMAC project. Accessed on March 24th 2017 at https://sites.google.com/site/admacsite/
 * Rodriguez-Garza J. A., and J. J. Reynoso-Campos. 2013. Hormigas (Hymenoptera: Formicidae) del género Pseudomyrmex encontradas en el estado de Quintana Roo, México. In Formicidae de Mexico (eds. M. Vasquez-Bolanos, G. Castano-Meneses, A. Cisneros-Caballero, G. A. Quiroz-Rocha, and J. L. Navarrete-Heredia) p21-32.
 * Valdes-Rodriguez S., P. Chacon de Ulloa, and I. Armbrecht. 2014. Soil ant species in Gorgona Island, Colombian Pacific. Rev. Biol. Trop. 62 (1): 265-276.
 * Ward P. S. 1990. The Ant Subfamily Pseudomyrmecinae (Hymenoptera: Formicidae): Generic Revision and Relationship to Other Formicids. Systematic Entomology 15: 449-489
 * Ward, P. S. 1989. Systematic Studies on Pseudomyrmecine Ants: Revision of the Pseudomyrmex Oculatus and P. Subtilissimus Species Groups with Taxonomic Comments on Other Species. Questiones Entomologicae 25: 393-468