Derivatio nominis: from Tian Shan, the region of the first finding.
Type material examined: 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.
Material examined: 32 samples with 119 workers were subject to a numeric character analysis (Fig. 21): China (28), Kazakhstan (1), Kyrgyzstan (3). For details, see Appendix, as digital supplementary material to this article, at the journal's web pages.
Description of worker (Tab. 1, Figs. 9, 16): small Ser-viformica species (CS 1.220 mm). Compared to F. cuni-cularia , 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 μ m 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. Meta-notal 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 ter-giteswith transverse microripples of a significantly larger distance than in F. cunicularia (RipD 6.2 μ m, Fig. 16), increasing from West (W-Tianshan, E-Kazakhstan: 5.7 μ m) to East (Bogda Shan: 6.5 μ m). 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.
Comments on taxonomy: The character combination and overall phenotypic impression of F. tianshanica sp. n. is similar to that of F. cunicularia and F. persica sp. n. , and we assume that these species are closely related allopatric and parapatric species. The discrimination, however, seems to be no problem. A three-class DA considering the characters CS, CL / CW1.4, SL / CS1.4, OceD / CS1.4, EYE / CS1.4, PEW / CS1.4, nPN1.4, nMN1.4, nPRME1.4, nPE1.4, nHFFL1.4, RipD1.4, sqPDG1.4, and PIGM 1.4, separated each of the 138 nest samples of these three species with p> 0.97 and 0% error indication in a LOOCV-DA (Fig. 17). The type samples were allocated to the right clusters with the following probabilities: neotype sample of F. cunicu-laria (p = 1.000), the holotype sample of F. cunicularia fuscoides and syntype sample of F. fusca var. rubescens (both p = 1.000, to F. cunicularia ), the holotype sample of F. tianshanica sp. n. (p = 0.999) and holotype sample of F. persica sp. n. (p = 0.998). F. tianshanica sp. n. is in no contact with F. persica sp. n. but is sympatric with F. cunicu-laria in the Tarbagatay-Saur Mountains in East Kazakhstan. There seems to exist no reduction of interspecific pheno-typic 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 sp. n. 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 meso-somas 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 but the problem needs a detailed investigation by integrative taxonomy.
32 samples with 119 workers were subject to a numeric character analysis of 18 characters. China : Bogda Shan (No. 148),18.IX.2004 [ 43.869° N , 88.138° E ] ;Bogda Shan (No. 152), 18.IX.2004 [ 43.868° N , 88.138° E ] ;Bogda Shan (No. 166), 19.IX.2004 [ 43.871° N , 88.143° E ] ;Bogda Shan (2 samples, No. 173, 174), 19.IX.2004 [ 43.868° N , 88.143° E ] ;Bogda Shan (No. 177), 20.IX.2004 [ 43.864° N , 88.146 E ] ;Bogda Shan (No. 182), 20.IX.2004 [ 43.861° N , 88.146° E ] ;Bogda Shan (No. 186), 20.IX.2004 [ 43.861° N , 88.144° E ] ;Bogda Shan (No. 188), 20.IX.2004 [ 43.852° N , 88.162° E ] ;Bogda Shan (No. 192), 20.IX.2004 [ 43.840° N , 88.173° E ] ;Bogda Shan (No. 193), 20.IX.2004 [ 43.841° N , 88.173° E ] ;Bogda Shan (No. 194), 21.IX.2004 [ 43.821° N , 88.181° E ] ;Bogda Shan (No. 195), 21.IX.2004 [ 43.821° N , 88.180° E ] ;Bogda Shan (No. 196), 21.IX.2004 [ 43.819° N , 88.186° E ] ;Bogda Shan (No. 199), 21.IX.2004 [ 43.817° N , 88.191° E ] ;Bogda Shan (No. 202), 21.IX.2004 [ 43.835° N , 88.172° E ] ;Bogda Shan (No. 206), 22.IX.2004 [ 43.858° N , 88.177° E ] ;Bogda Shan (No. 216), 23.IX.2004 [ 43.868° N , 88.215° E ] ;Bogda Shan (No. 217), 23.IX.2004 [ 43.868° N , 88.210° E ] ;Bogda Shan (2 samples, No. 209, 211), 23.IX.2004 [ 43.859° N , 88.180° E ] ;Bogda Shan (2 samples, No. 223, 224), 23.IX.2004 [ 43.859° N , 88.175° E ] ;Bogda Shan (2 samples, No. 230, 233), 23.IX.2004 [ 43.859° N , 88.174° E ] ;Bogda Shan (No. 236), 25.IX.2004 [ 43.923° N , 88.233° E ] ;Bogda Shan (No. 252), 25.IX.2004 [ 43.943° N , 88.173° E ] ;Bogda Shan (No. 258), 26.IX.2004 [ 43.936° N , 88.106° E ] .Kazakhstan : Saur , 25.VII.2001 [ 47.357° N , 85.518° E ] .Kyrgyzstan : Kara Bura , 29.VII.1998 [ 42.250° N , 71.549° E ] ;Kap Tshigai vall. (samples No. 3, 4: type), 16.VII.1998 [ 42.408° N , 73.789° E ] .
Distribution and biology: 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. 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.
