Myrmica phalacra

Two workers and two gynes were found on mountain meadows at the altitudes ca. 2000 m.

Identification
A member of the pachei group. It is characterized by the quite coarse transversal sinuous rugosity (numbering < 20) on the mesonotal and propodeal dorsum and by the absence of the decumbent hairs on the lateral margins of head posterior to the eyes. In some respects, it resembles Myrmica hlavaci, but differs from it by partly reduced rugosity on the head dorsum, where the frons (level with the eyes) has < 15 fine, slightly sinuous longitudinal rugae, with only some of them extending unbroken to the occipital margin. (Radchenko and Elmes 2010)

Distribution
Known only from the type locality from Shaanxi Province of China.

Distribution based on Regional Taxon Lists
Palaearctic Region: China.

Castes
Males have yet to be collected.

Nomenclature

 *  phalacra. Myrmica phalacra Radchenko & Elmes, 2009a: 74, figs. 21-30 (w.q.) CHINA. See also: Radchenko & Elmes, 2010: 216.

Worker
Head longer than broad, with weakly convex sides and occipital margin, and broadly rounded occipital corners; anterior clypeal margin rounded, slightly prominent and not-notched medially. Upper latero-ventral corners of head rounded, not pointed (seen in profile). Mandibles with 7-8 teeth. Frontal carinae very feebly curved, merging with rugae that extend to the posterior third of head dorsum, they do not curve outwards and do not merge with fine striae that surround antennal sockets. Frons wide, frontal lobes not extended. Scape relatively long, slightly longer than head width, gradually, but distinctly, curved at the base, without any trace of lobe or carina. Alitrunk long and low, promesonotum slightly convex (seen in profile), promesonotal suture indistinct (seen from above). Metanotal groove very shallow. Propodeal lobes rounded apically. Propodeal spines relatively short, straight, sharp, directed backward and somewhat upward at an angle of about 45°. Petiole low, with distinct peduncle, its anterior surface concave, dorsum of node widely rounded. Postpetiole subglobular, its anterior and dorsal surfaces forming a regular arch. Spurs on middle and hind tibiae well developed and pectinate.

Head with partly reduced rugosity: frons with fine longitudinal rugae, < 15 rugae between frontal carinae level with the eyes, but only some of them run unbroken posteriorly to reach the occipital margin; temples with fine reticulation, surface between rugae quite coarsely punctatcd, appearing dull. Clypeus with a few fine rugulae, its surface shiny; frontal triangle smooth and shiny; mandibles longitudinally rugose.

Pronotal dorsum with irregular sinuous rugulosity and reticulation, combined with transverse rugae; pronotal sides anteriorly reticulated, posteriorly punctato- striated. Mesonotal and propodeal dorsum with < 20 quite coarse transverse sinuous rugae. Lower parts of mesopleura and sides of propodeum punctated and with longitudinal rugosity. Surface between rugae on alitrunk finely punctated, though appearing more or less shiny. Petiole and post petiole with some short irregular striae, surface finely punctated but appearing more or less shiny. Gaster smooth and shiny.

Head margins without decumbent or subdecumbent short hairs, only genae and occiput have a few long suberect hairs; alitrunk dorsum with sparse long hairs; petiole with 6-8 long hairs. Scape and tibiae with subdecumbent hairs. Body colour dark reddish-brown, appendages somewhat lighter.

Queen
Generally similar to workers by the shape of head, frontal lobes, propodeal spines and waist. Rugosity on the head dorsum more developed than in workers. Alitrunk long and low, coarsely sculptured; pronotum with reticulation, scutum with sinuous rugae, diverging backwards to form a subtriangular pattern on the posterior half of scutum; scutellum with semiconcentric rugae; only propodeal dorsum with coarse transverse rugae; mesopleura and lower part of propodeal sides longitudinally rugose.

Type Material
Holotype, w, China, Shaanxi Prov., Qin Ling Shan, 118 km E Xian, 110°06'E, 34°25'N, Stop 1950-2000 m, No. 969, 19.viii.1995, leg. Wrase ; paratypes: 1 w and 2 q with the same label as holotype (IZK,, Schulz).

Etymology
From the Greek word phalachros = bald, to describe the complete absence of hairs, even subdecumbent ones, on the sides on the head.

References based on Global Ant Biodiversity Informatics

 * Chen Z. L., S. Y. Zhou, and J. H. Huang. 2016. Seven species new to science and one newly recorded species of the ant genus Myrmica Latreille, 1804 from China, with proposal of a new synonym (Hymenoptera: Formicidae). ZooKeys 551: 85–128.
 * Radchenko A. G.; and G. W. Elmes. 2009. Taxonomic revision of the pachei species-group of the genus Myrmica Latreille (Hymenoptera: Formicidae). Annales Zoologici (Warsaw) 59: 67-92.