Formica tianshanica

Apparently rare in regions with competing montane and subalpine Serviformica species as observed in the Tian Shan, Tarbagatay and Quin Ling Shan. In contrast, very abundant in the Bogda Shan where these competitors are missing, occupying here a wide altitudinal range from 1380 to 3010 metres. This correlates with variable habitat selection in Bogda Shan: it was found here in pastures of any kind above and below the tree line, in open rural areas, in clear-cuttings of former Picea forest, in habitat mosaics of grassland, Picea and Juniperus and in light Picea forests. (Seifert and Schultz 2009)

Identification
Seifert and Schultz (2009) - A member of the Formica rufibarbis group. The character combination and overall phenotypic impression of F. tianshanica is similar to that of Formica cunicularia and Formica persica, and we assume that these species are closely related allopatric and parapatric species. The discrimination, however, seems to be no problem, using a three class discriminant analysis. F. tianshanica is in no contact with F. persica but is sympatric with F. cunicularia in the Tarbagatay-Saur Mountains in East Kazakhstan. There seems to exist no reduction of interspecific phenotypic contrast in this sympatric region but the small sample size available does not allow to really discuss possible interspecific hybridisation.

Considerable morphological variation within the F. tianshanica population is apparently existing in the gynes: Two gynes from the Tian Shan and Tarbagatay differ from five gynes from the Bogda Shan by larger CS, smaller OceD / CS and EYE / CS, more voluminous mesosomas and lighter colour. The sparse information currently available does not allow to decide if these differences represent a gyne dimorphism (as for instance found in European Formica fusca) or indicate different allopatric species. Since there are no significant differences between the worker populations of Tian Shan and Bogda Shan, we provisionally assume a gyne polymorphism.

Distribution
Seifert and Schultz (2009) - Only known from mountain areas of the Turkestanian floristic subregion (Tian Shan, Tarbagatay-Saur, Bogda Shan). Range between 71° and 89° E and 42° and 47°N.

Distribution based on Regional Taxon Lists
Palaearctic Region: China, Kyrgyzstan.

Nomenclature

 *  tianshanica. Formica tianshanica Seifert & Schultz, 2009: 267, figs. 9, 16 (w.) KYRGIZSTAN.

Worker
Small Serviformica species (CS 1.220 mm). Compared to Formica cunicularia, head more elongated (CL / CW1.4 1.143), scape slightly shorter (SL / CL1.4 1.057) and petiole narrower (PEW / CS1.4 0.434). Distance between lateral ocelli moderate (OceD / CS1.4 0.165), eyes rather large (EYE / CS1.4 0.299). Frontal triangle finely transversely rippled and with 25 - 40 short pubescence hairs. Eyes with microsetae of 7 - 12 μm maximum length. Total mean of unilateral setae numbers on different body parts predicted for a specimen with CS = 1.4 mm: pronotum 1.7, mesonotum 0.5, flexor profile of hind tibia 0.6. Petiole, posterior margin of head, propodeum, and dorsolateral metapleuron normally without setae. Ventral coxae and gaster tergites with long setae. Dorsal mesonotum in lateral aspect broadly convex. Metanotal depression of moderate depth. Propodeal dome in profile convex, the basal profile sometimes slightly concave, in smaller specimens more or less linear and horizontal. Dorsal crest of petiole in frontal view bluntly angled in smaller specimens to broadly convex in larger specimens in which the median portion is occasionally linear or weakly excavate. Petiole scale in lateral aspect slender, with convex anterior and more straight posterior profile. Gaster tergites with transverse microripples of a significantly larger distance than in F. cunicularia (RipD 6.2 μm, Fig. 16), increasing from West (W-Tianshan, E-Kazakhstan: 5.7 μm) to East (Bogda Shan: 6.5 μm). Dorsum of gaster covered by dense silvery pubescence (sqPDG 3.3). Pubescence on head, mesosoma and petiole less dense, ants appear mildly shining. Posterior vertex, sometimes dorsal promesonotum, coxae, and all appendages normally brown, gaster always dark brown. Other body parts more or less reddish, in the Bogda Shan population more yellowish-brown.

Type Material
Holotype worker plus 4 worker paratypes labelled “KIR: 42.4079°N, 73.7893°E Kap Tshigai valley, R.Schultz 1998.07.16-004” and “Holotype Formica tianshanica Seifert & Schultz” / “Paratype Formica tianshanica Seifert & Schultz”, SMN Görlitz; 3 mounted paratype workers and 10 paratype workers in ethanol, coll. RS.

Etymology
From Tian Shan, the region of the first finding.

References based on Global Ant Biodiversity Informatics

 * Guénard B., and R. R. Dunn. 2012. A checklist of the ants of China. Zootaxa 3558: 1-77.
 * Seifert B., and R. Schultz. 2009. A taxonomic revision of the Formica rufibarbis Fabricius, 1793 group (Hymenoptera: Formicidae). Myrmecological News 12:255-272.