Myrmica taibaiensis

Two collections were made from nest in a rotten tree trunk and rotten tree root, in mountain forest at an altitude between 2000 and 2200 m.

Identification
Radchenko and Elmes (2010) - A member of the pachei species group and redescribed workers and queen (Radchenko and Elmes 2009a). Wei C. et al. (2001, p. 563) noticed: “The new species is close to Myrmica inezae. It differs from the later by the shape and number of mandible teeth, the shape of propodeal spines, and the colour of body”. Although in some respects there are similarities between the inezae- and pachei-groups (see Radchenko and Elmes 2001b), the authors were certainly referring to its similarity to Myrmica weii, which they had misidentified as M. inezae (see also Radchenko et al. 2008). The mesonotal and propodeal dorsum of M. taibaensis is transversally rugose, while the pronotal dorsum is reticulate; the occipital and lateral margins of the head above the eyes have numerous short subdecumbent hairs; the propodeal spines are long, but massive, strongly widened at the base.

Distribution
Shaanxi Province, China.

Distribution based on Regional Taxon Lists
Palaearctic Region: China.

Nomenclature

 *  taibaiensis. Myrmica taibaiensis Wei, Zhou & Liu, in Wei, Zhou, He & Liu, 2001: 562, figs. 2-3 (w.q.) CHINA. See also: Radchenko & Elmes, 2009a: 69; Radchenko & Elmes, 2010: 301.

Worker
Radchenko and Elmes (2009) - Head longer than broad, with very weakly convex sides, almost flat occipital margin, and rounded occipital corners; anterior clypeal margin convex, slightly prominent, not-notched medially. Upper latero-ventral corners of head rounded, not pointed (seen in profile). Mandibles with 7-9 teeth. Frontal carinae curved outwards to merge with rugae, which surround antennal sockets: frons wide, frontal lobes very feebly extended. Antennal scape quite long, subequal to head width, gradually curved at the base, without any trace of lobe or carina.

Alitrunk with convex pronotal dorsum and somewhat flattened mesonotal dorsum (seen in profile), promesonotal suture indistinct (seen from above). Metanotal groove deep and abrupt. Propodeal lobes rounded apically. Propodeal spines long, massive, strongly widened at the base and often slightly downcurved on their distal third. Petiole with distinct peduncle longer than high, its anterior surface concave, not steep. Node dorsum slightly convex, gradually sloping backward; postpetiole subglobular. Spurs on middle and hind tibiae well developed and pectinate.

Frons with numerous fine, but not sinuous, subparallel longitudinal rugulae, their number between frontal carinae level with the eyes > 15; remaining parts of head dorsum with sinuous rugae and reticulation, clypeus with fine longitudinal rugae. Surface of head between rugae appearing shiny: frontal triangle smooth and shiny: mandibles longitudinally rugulose.

Pronotal dorsum with coarse reticulation; mesonotal and propodeal dorsum with sinuous transverse rugue; sides of pronotum, mesopleura and sides of propodeum with sinuous longitudinal rugae. Surface between rugae very finely punctated, appearing shiny. Petiolar node dorsum with short longitudinal rugae, dorsum of postpetiole with longitudinally-concentric rugosity, surface between rugae appearing shiny. Gaster smooth and shiny.

Occipital margin and lateral margins of head above the eyes with short subdecumbent hairs, a few long hairs present only on occipital margin and genae. Alitrunk and waist with long outstanding hairs. Scape and tibiae with subdecumbent pilosity.

Sides of alitrunk and waist yellowish-red, pronotal dorsum and dorsum of petiole and postpetiole darker head dorsum and gaster dark brown; appendages yellowish-red.

Queen
Radchenko and Elmes (2009) - Small, smaller than the largest workers. Otherwise, generally similar to workers by the shape of head, sculpture and pilosity of the body, but the petiole is relatively longer and wider, and propodeal spines shorter.

Type Material
Holotype worker, Mt. Taibai 2200 m, Taibai Co., Shaanxi Prov., nested in rotten trunk of tree, in the forest, 19 Aug. 1997, Wei Congo Paratypes: 35 workers, 5 females, Mt. Taibai 2000 m, in rotten root in the forest, 27 Aug. 1997, Wei Cong.

Etymology
Radchenko and Elmes (2010) - a combination of the name Taibai with the Latin suffix ensis = place of origin, to indicate that it was found on Mt. Taibai, the main peak of the Qinling Mountain, Shaanxi Province, China.