Perissomyrmex snyderi

Perissomyrmex is a small genus with five of its six species occurring in Asia. The disjunct Central American range of P. snyderi is the outlier. Longino and Hartley (1995) hypothesized this species has a relictual distribution, i.e., a remainder of what putatively once was a much more widely distributed lineage.

Identification
Ogata and Okito (2007) - Diagnosed by the presence of a subpetiolar process in the workers, the dentition of the anterior margin of the clypeus and the coarse and irregular sculpturation on the head. Shows great variation in worker caste body size, shape of spines, and teeth on the anterior clypeal margin. The degree of the protuberance of the anterior clypeal margin varies but is generally less distinct than Asian Perissomyrmex.

Distribution based on Regional Taxon Lists
Neotropical Region: Guatemala, Honduras, Mexico. Oriental Region: Nepal.

Biology
Longino and Hartley (1995) - Berlese samples of this species were collected by R. S. Anderson from cloud forest leaf-litter in southern Mexico and Guatemala. These consisted of three adjacent samples from the lower slopes of Volcin Tacana, North Union Juarez, 1507’N, 9206’W, Chiapas, Mexico, between 1950 and 2000m elevation. P. S. Ward collected P. snyderi from another Chiapas cloud forest site, also from leaf-litter sampling, at 1713’N, 9258’W, 1700m elevation. That location was described as having a cloud forest with more tropical than temperate elements, with Pinus and Liquidambar in the vicinity but not at the particular collection site of the ants.

Worker
Longino and Hartley (1995) - Measurements of individuals (n=206) from the Anderson samples (see biology section above) showed that the workers exhibited a diphasic allometry polymorphism with distinctive minor and major worker castes.

Nomenclature

 * . Perissomyrmex snyderi Smith, M.R. 1947i: 282, figs. 1, 2 (w.) GUATEMALA.
 * Type-material: holotype worker, 1 paratype worker.
 * Type-locality: Guatemala (no further data); in begonia root from Guatemala, intercepted in quarantine at Hoboken, New Jersey, U.S.A.
 * Type-depository: USNM.
 * Status as species: Kempf, 1972a: 182; Bolton, 1981b: 283; Bolton, 1995b: 316; Longino & Hartley, 1995: 195 Radchenko, 2003: 18 (in key); Xu & Wang, 2004: 218 (in key); Zhou & Huang, 2006: 193 (in key); Ogata & Okido, 2007: 362 (redescription); Branstetter & Sáenz, 2012: 259.
 * Distribution: Guatemala, Mexico.

Worker
Ogata and Okido (2007) - TL 3.74-4.94, HL 0.88-1.24, HW 0.88-1.34, CI 100-108, SL 0.82-0.94, SI 73-93, PW 0.56-0.72, ML 0.98-1.20, GL 1.00-1.40, GW 0.80-1.06.

Polymorphic. Labrum with lamellate flange developed at basal part of curvature. Anterior clypeal margin with 3 pairs of projection, the shape and size varying to reduce or fused; basically, the median pair broad and robust, inner lateral pair smaller; outer lateral pair smallest, sometimes reduced or lost; the median notch roundly concave; in some case the median paired teeth fused without median notch in major worker. Propodeal spine straight or slightly curved upward. Subpetiolar process present anteriorly; ventral margin of petiole almost straight in profile; anterior portion of petiole diverging toward midlength of petiole in dorsal view. Sculpture on head and mesosoma irregularly costate. Body color blackish.

References based on Global Ant Biodiversity Informatics

 * Dattilo W. et al. 2019. MEXICO ANTS: incidence and abundance along the Nearctic-Neotropical interface. Ecology https://doi.org/10.1002/ecy.2944
 * 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 D.A. Hartley. 1994. Perissomyrmex snyderi (Hymenoptera: Formicidae) is native to Central America and exhimits worker polymorphism. Psyche 101:195-202
 * Vásquez-Bolaños M. 2011. Lista de especies de hormigas (Hymenoptera: Formicidae) para México. Dugesiana 18: 95-133