Hylomyrma montana

Hylomyrma montana  is the first recorded species in the genus known to be exclusively restricted to cloud forest habitat.

Identification
Pierce et al. (2017) - Postpetiolar dorsum smooth and shining or weakly striate; eye relatively small (OI 21 - 24).

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

Nomenclature

 *  montana. Hylomyrma montana Peirce, Branstetter & Longino, 2017: 138, figs. 3, 4, 7 (w.) COSTA RICA.

Worker
(holotype): EL 0.195, EW 0.134, GSL 0.065, HFL 0.796, HL 0.833, HW 0.845, ML 1.116, OMD 0.133, PpL 0.278, PpW 0.295, PronW 0.563, SL 0.676, SPL 0.282, CI 101, GSI 6, OI 23, PpWI 106, SI 80, SPI 33. Measurements (range, n = 20): EL 0.175 - 0.218, EW 0.124 - 0.149, GSL 0.047 - 0.123, HFL 0.775 - 0.945, HL 0.813 - 0.948, HW 0.804 - 0.899, ML 1.03 - 1.236, OMD 0.108 - 0.151, PpL 0.246 - 0.314, PpW 0.289 - 0.371, PronW 0.544 - 0.645, SL 0.621 - 0.742, SPL 0.248 - 0.329, CI 94 - 102, GSI 4 - 10, OI 21 - 24, PpWI 106 - 124, SI 75 - 83, SPI 31 - 39.

Head subquadrate; in full-face view sides and dorsum relatively straight, occipital corners rounded. Clypeus bidentate, denticles moderately long and projecting; clypeal margin between denticles slightly concave. Clypeus and frontal area rugose. Frontal lobes rather large, with convex sides projecting over antennal insertions. Head in full-face view densely longitudinally striatorugose. Rugae beginning at mandibular insertions and frontal lobes, and continuing uninterrupted to occipital margin, occasionally intersecting and forming a sub-reticulate pattern. Area between rugae micro-punctatostriate. Head with moderate pilosity, hairs golden in color and pointed at ends. Eye consisting of more than 40 facets, relatively short and distant from anterolateral margin of head. Antennal scapes rugose, curved, thinner towards antennal insertions and thicker towards apices. Pilosity of scapes consisting of suberect to erect hairs. Funicular segments of antennae gradually increasing in size, and covered with sub-erect hairs.

Mesosoma in profile view convex from neck to propodeal spines, profile interrupted by rugae. Sides of mesosoma densely reticulate-rugose, interrugal spaces micropunctatostriate, subopaque. Pronotal and metanotal grooves absent. In profile view, dorsum of mesosoma with long and pointed erect hairs. Propodeal spines medium sized and projecting over inferior propodeal plates.

Petiole elongated, lacking differentiated peduncle and node. Sides and dorsum of petiole rugose. Postpetiole in profile subquadrate; ventral surface flat, dorsal surface slightly convex. In dorsal view, postpetiole sub-triangular, sides flaring from anterior margin to posterior margin. Dorsal surface of postpetiole largely smooth and shining, with at most a few faint longitudinal costulae. Gaster largely smooth and shining. Tergum 1 of gaster with short longitudinal costulae, less than 0.1 mm in length, in some specimens nearly absent.

Overall body color dark reddish-brown. Legs and antennae somewhat lighter brown.

Type Material
Holotype worker: Costa Rica, Limón, Cerro Platano, 9.86732 - 83.24131 ± 20 m, 1130 m above sea level (a.s.l.), 18 June 2015 (Project ADMAC, collection code Wm-E-03-1-01) [CAS, unique specimen identifier CASENT0637306]. Paratype workers (n = 12): same data as holotype, CASENT0638686; , CASENT0638689; , CASENT0638690; , CASENT0638691; , CASENT0638721, CASENT0638702, CASENT0638694, CASENT0638692, CASENT0638699, CASENT0638696, CASENT0638719, CASENT0638695].

Etymology
The name is in reference to the montane distribution of the species.

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.
 * Pierce M. P., M. G. Branstetter, and J. T. Longino. 2017 . Integrative taxonomy reveals multiple cryptic species within Central American Hylomyrma FOREL, 1912 (Hymenoptera: Formicidae). Myrmecological News 25: 131-143.