Myrmica pleiorhytida

Workers were found on mountain meadows at altitudes between 2400 and 3500 m.

Identification
A member of the pachei group. It is characterized by the following combination of the features: the pronotal dorsum with reticulation and sides with longitudinal rugulae; the mesonotal and propodeal dorsum with fine transversal rugae numbering > 35; lateral and occipital margins of the head with the long numerous suberect to erect hairs; the head only slightly longer than broad (CI < l.15), subsquare, with the distinctly marked occipital corners; whole head dorsum with the very dense, fine, almost straight, slightly divergent posteriorly longitudinal rugae, their number between frontal carinae level with the eyes> 30. (Radchenko and Elmes 2010)

Distribution
Yunnan Province, China.

Distribution based on Regional Taxon Lists
Palaearctic Region: China.

Castes
Males are unknown.

Nomenclature

 *  pleiorhytida. Myrmica pleiorhytida Radchenko & Elmes, 2009a: 78, figs. 41-45 (w.) CHINA. See also: Radchenko & Elmes, 2010: 218.

Worker
Head subrectangular, longer than broad, with weakly convex sides and occipital margin, and narrowly rounded occipital corners; anterior clypeus margin relatively narrowly rounded, but not prominent and not-notched medially. Upper latero-ventral corners of head rounded, not pointed (seen in profile). Mandibles with 7 teeth. Frontal carinae curved outwards to merge with rugae that surround antennal sockets: frons wide, frontral lobes not extended. Scape relatively long, subequal to head width, gradually though distinctly curved at the base, without any trace of lobe or carina.

Alitrunk relatively robust, promesonotum convex (seen in profile), promesonotal suture well developed (seen from above). Metanotal groove distinct though not very deep. Propodeal lobes rounded apically. Propodeal spines moderately long, straight, sharp, directed backward at an angle of about 30°. Petiole with quite short but distinct peduncle, Its anterior surface feebly concave, almost straight, dorsum of node broadly rounded. Postpetiole subglobular, its anterior and dorsal surfaces forming a regular arch. Spurs on middle and hind tibiae well developed and pectinate.

Whole head dorsum with very dense, fine, almost straight, slightly posteriorly diverging longitudinal rugae, their number between frontal carinae level with the eyes > 30. Clypeus with coarser longitudinal rugae, frontal triangle smooth. Surface between rugae finely but densely punctated, appearing dull (except for clypeus and frontal triangle, which are shiny). Mandibles longitudinally rugose.

Pronotal dorsum reticulate, its sides longitudinally rugulose; mesonotal and propodeal dorsum with > 35 fine transverse rugae; lower parts of mesopleura and sides of propodeum with longitudinal rugosity. Surface between rugae on alitrunk smooth and shiny. Petiole and post petiole with short irregular rugulae, and densely, though not coarsely, punctated, appearing dull. Gaster with very fine superficial microsculpture, appearing shiny.

Head margins with abundant, quite long, slightly curved suberect hairs; alitrunk dorsum with longer hairs; petiole with 6-8 long and about to shorter hairs. Scape with hairs at an angle 30-45° to the surface, tibiae with subdecumbent hairs. Body colour dark reddish- brown, appendages somewhat lighter.

Queen
Radchenko and Elmes (2010) - The shape and sculpture of head is similar to that of workers (see also Radchenko and Elmes 2009a). Scutum and scutellum longitudinally rugose, propodeal dorsum with transversal rugosity. Petiolar node and postpetiolar dorsums, especially in their posterior half, ransversally rugulose. Propodeal spines somewhat shorter and stouter than in workers. Colour and character of pilosity - as in workers.

Type Material
Holotype worker, China, N Yunnan. env. Xinguan, 2400 m, 29.vii.2002, leg. S. Murzin and I. Shokhin (ZISP); paratypes: worker, China, N Yunnun, Zhongdiun, 3300 mm, 6-8.vii,2002, leg. S. Murzin and I. Shokhin; 8 workers, China, Yunnan, Habashan Mts., 3150-3500 mm, 27°19'W, 100°08'E, 11, 16-18.vi.2004, leg. R. + H. Fouquti (WGS 84) (ZISP,, , MSNV).

Etymology
Radchenko and Elmes (2010) - from the combination of the Greek words pleion = more, abundant or numerous, and rhytida = crease or wrinkle (ruga), to described the sculpture of the head and alitrunk dorsums.