Hylomyrma plumosa

Identification
Pierce et al. (2017) - At least some of dorsal setae branched, usually trifid. Though the plumose setae and short gastral striation of Hylomyrma plumosa are distinctive, the species is otherwise extremely similar to Hylomyrma dentiloba and Hylomyrma versuta.

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

Nomenclature

 *  plumosa. Hylomyrma plumosa Peirce, Branstetter & Longino, 2017: 140, figs. 3, 5, 7 (w.) COSTA RICA.

Worker
(holotype worker): EL 0.211, EW 0.13, GSL 0.089, HFL 0.735, HL 0.799, HW 0.784, ML 1.042, OMD 0.109, PpL 0.253, PpW 0.3, PronW 0.573, SL 0.591, SPL 0.228, CI 98, GSI 9, OI 27, PpWI 119, SI 75, SPI 29. Measurements (range, n = 15): EL 0.202 - 0.235, EW 0.109 - 0.138, GSL 0.089 - 0.12, HFL 0.709 - 0.801, HL 0.793 - 0.871, HW 0.759 - 0.842, ML 0.991 - 1.137, OMD 0.095 - 0.12, PpL 0.227 - 0.285, PpW 0.293 - 0.331, PronW 0.55 - 0.618, SL 0.544 - 0.622, SPL 0.212 - 0.253, CI 93 - 99, GSI 8 - 11, OI 26 - 28, PpWI 114 - 133, SI 70 - 77, SPI 27 - 31.

Head subquadrate, occipital margin very slightly convex, occipital corners rounded. Clypeus bidentate, area between denticles mostly straight. Frontal lobes convex, ending anteriorly in a rounded angle, projecting over antennal insertions. Rugae on head running longitudinally and parallel, not intersecting; rugae interrupted occasionally by short gaps. Interrugal spaces microstriate, subopaque. Eye large, ending anteriorly in elongate tapering lobe. Scape tapered toward insertions and covered by abundant suberect non-branched hairs.

In profile view mesosoma convex, profile uninterrupted. Sides and dorsum of mesosoma reticulate rugose, interrugal spaces microstriate, subopaque. Propodeal spines relatively short, projecting posteriorly.

Peduncle of petiole present but not well developed. Sides and dorsum of petiole rugulose. Postpetiole subquadrate, covered on dorsum by longitudinal striae. Gaster mostly smooth and shining, striations on dorsum of tergum 1 short, but longer than Hylomyrma montana.

Body color reddish to reddish-brown, legs somewhat lighter, gaster darker brown. Dorsum of head, mesosoma, and gaster abundantly setose, at least some setae branched, bifid or more often trifid.

Type Material
Holotype worker: Costa Rica, Limón, Hitoy-Cerere, 9.66480 - 83.02346 ± 10 m, 250 m a.s.l., 10 June 2015 (collection code: ADMAC#Wa-E-02-2-38), unique specimen identifier CASENT0638700]. Paratype workers (n = 13): Same data as holotype, CASENT0638687; , CASENT0638688; , CASENT0638693; , CASENT0638697; , CASENT0638720, CASENT0638701, CASENT0638703, CASENT0638725, CASENT0638698, CASENT0638700, CASENT0638722, CASENT0638724, CASENT0638735.

Etymology
This species is named for the distinctive branched hairs that distinguish it from all other Hylomyrma.