Myrmica bactriana

This species was found at high altitudes, on grasslands and subalpine meadows between 3500 and 3800 m. Almost certainly it nests in the soil.

Identification
A member of the smythiesii group. M. bactriana is very similar to Myrmica ruzskyana, differing only by its distinctly longer scape (SI2 ~ 0.93 vs. :S 0.91) with more abundant and suberect hairs, and it is quite possible this represents different populations of the same species. (Radchenko and Elmes 2010)

Distribution based on Regional Taxon Lists
Oriental Region: Nepal, Tibet. Palaearctic Region: China.

Castes
Queens are unknown.

Nomenclature

 *  bactriana. Myrmica smythiesi var. bactriana Ruzsky, 1915a: 438, figs. 16-18 (w.m.) TIBET. Raised to species: Radchenko & Elmes, 2010: 96. Senior synonym of furva: Radchenko & Elmes, 2010: 96.
 * furva. Myrmica tibetana var. furva Ruzsky, 1915a: 441 (w.) TIBET. Junior synonym of tibetana: Radchenko, 1994a: 41; of bactriana: Radchenko & Elmes, 2010: 96.
 * exigua. Myrmica smythiesi subsp. exigua Ruzsky, 1915a: 440, figs. 19, 20 (w.m.) TIBET.
 * [Junior primary homonym of exigua Buckley, 1867: 342, above.]
 * Replacement name: ruzskyana Radchenko & Elmes, 2010: 249.
 * Junior synonym of bactriana: Seifert et al., 2018: 105.
 * ruzskyana. Myrmica ruzskyana Radchenko & Elmes, 2010: 249.
 * Replacement name for exigua Ruzsky, 1915a: 440. [Junior primary homonym of exigua Buckley, 1867: 342.]
 * Junior synonym of bactriana: Seifert et al., 2018: 103.

Type Material
Radchenko and Elmes (2010) - Myrmica ruzskyana: Lectotype (designated here), w, [river Ba-chju, 12,000', Kam, bassin of riv. Yangtze, 2/3.viii.1900] (Moscow); paralectotypes: 14 w, 1 m with the same label (Moscow, Petersburg).

Seifert et al. (2018) - Myrmica bactriana: Radchenko & Elmes (2010) published a lectotype worker stored in ZM St. Petersburg and cite its label as “okr. ur. Darindo, Kam, verkh. Goluboj, Kozlov, 1/3.VIII.00” [in Cyrillic]. The term “1/3.VIII.00” stands probably for the first decade of August (I. Kabak, pers. comm.). This site is situated at the upper course of Yangtse at 33.054° N, 96.903° E and 3850 m. No type specimens could be discovered in the collection St. Petersburg during a search by D. Dubovikov in 2013 but the identity of this taxon and of M. ruskyana Radchenko & Elmes, 2010 can be concluded with low risk of error from Radchenko & Elmes drawings of the lectotypes and the geographic data.

Seifert et al. (2018) - Myrmica ruzskyana: This is a replacement name for the primary homonym Myrmica smythiesii var. exigua Ruzsky, 1915. Radchenko & Elmes (2010) published a lectotype labeled “rechka Bachyu, 12.000’, Kam, bass. Goluboj r., Kozlov, 2/3. VIII.00” [in Cyrillic]. “2/3. VIII”. means probably the second decade of August (I. Kabak, pers. comm.). Though the label shows another locality name, the travelling report of Kozlov does not allow separating this site geographically from the lectotype locality of M. bactriana. According to Kozlov’s map, he had been in Darindo (locality of M. bactriana) on 8 August and in Ba-Tshu River on 9 - 20 August 1900. The linear distance between Darindo and the mouth of Ba-Tshu River is approximately 11 km and that between Darindo and the next station – the confluence of the Ba-Tshu and Dza-Tshu rivers, reached on 21 August – is about 27 km (I. Kabak, pers. comm.). Thus the collecting points are between 11 km and 27 km apart and both in the Yangtse basin close to the present town of Yushu. Type material was not available from ZM St. Petersburg and ZM Moscow.

Worker
Radchenko and Elmes (2010) - Head distinctly longer than broad, with subparallel sides, straight occipital margin and narrowly rounded occipital corners; anterior clypeal margin narrowly rounded, distinctly prominent with no medial notch. Upper latero-ventral corners of head rounded, not pointed (seen in profile). Mandibles with 6-7 teeth. Frontal carinae curved outwards to merge with rugae that surround antennal sockets. Frons wide (FI > 0.41), frontal lobes not extended (FLI < l.15). Scape distinctly shorter than head width (SI2 :S 0.91), weakly curved at the base, without any trace of lobe or carina. Alitrunk quite short, metanotal groove distinct, deep. Propodeallobes rounded apically. Propodeal spines short (ESLI < 0.24, mean 0.19), straight, thin, directed backward at an angle about 45°. Petiole with relatively short but distinct peduncle, its anterior surface slightly concave, dorsum of node rounded. Postpetiole higher than long (PPI1 < 0.87), its anterior and dorsal surfaces forming a regular arch. Spurs on middle and hind tibiae well developed and pectinate.

Frons with quite dense, fine, slightly sinuous longitudinal rugosity, numbering ca. 20 between frontal carinae level with the eyes, occiput and temples with fine reticulation, surface between rugae at most with superficial micropuntures, but appears shiny; clypeus with weak longitudinal carina and very fine rugulae, surface shiny; frontal triangle smooth and shiny; mandibles longitudinally rugose. Alitrunk with longitudinal, slightly sinuous but not coarse rugae. Surfaces between rugae on alitrunk smooth and shiny. Petiole and postpetiole with very fine longitudinal rugulosity, appearing shiny. Gaster smooth and shiny.

Head margins above the eyes with subdecumbent hairs, genae with a few long hairs; alitrunk dorsum with longer hairs; petiole with 6-8 long hairs. Scape and tibiae with subdecumbent to decumbent pilosity. Body colour reddish to reddish-brown, appendages somewhat lighter.

Male
Radchenko and Elmes (2010) - Head distinctly longer than broad (CI l.l6-1.20), with rounded occipital corners, sides and occipital margin feebly convex, anterior c1ypeal margin narrowly rounded and rominent, with no medial notch. Scape long (SI1 0.85-0.86, SI2 l.00-1.02) and very weakly curved at the base, antennae 13-segmented; second funicular segment subequal in length to the third one. Alitrunk relatively long (AI 1.64-1.66), scutum slightly convex, scutellum does not project dorsally above scutum when seen in profile. Propodeum without denticles, at most with small tubercles. Petiole relatively short, with slightly concave and steep anterior surface and widely rounded node dorsum (seen in profile); postpetiole higher than long, with convex dorsum.

Head dorsum (excluding frontal triangle) densely punctated, frons also finely longitudinally rugulose, surface of clypeus with reduced sculpture, appearing shiny. Scutum longitudinally rugulose, scutellum and posterior part of scutum quite coarsely punctated. Sides of pronotum and mesopleura finely longitudinally striated and punctated, sides of propodeum coarsely rugose and finely punctated. Petiole and postpetiole very finely superficially punctated but appear shiny.

Head margins and mandibles with numerous, relatively long, curved sub erect hairs. Alitrunk, waist and gaster with sparser hairs. Scape, tibiae and tarsi with quite dense decumbent to subdecumbent pilosity. Body colour dark brown to blackish-brown, appendages reddish-brown.

Etymology
Radchenko and Elmes (2010) - Myrmica bactriana: Bactria (or Bactriana) was an old province of Greater India centred on modern Tajikistan that has lent its name to many taxa from that region. We are not sure why Ruzsky chose the name bactriana for a Tibetan species unless he had in mind the Bactrian camels that live wild in parts of Tibet.

Radchenko and Elmes (2010) - Myrmica ruzskyana: Dedicated to the famous Russian myrmecologist M. D. Ruzsky, who originally named the species M. exigua.