Formica tarimica, Seifert & Schultz, 2009

Seifert, B. & Schultz, R., 2009, A taxonomic revision of the Formica rufibarbis Fabricius, 1793 group (Hymenoptera: Formicidae)., Myrmecologische Nachrichten 12, pp. 255-272 : 266-21

Formica tarimica sp. n.

Derivatio nominis: from the distribution in the Tarim Basin.

Type material examined: Holotype worker plus 4 worker paratypes labelled "CHI: 42.1251° N, 84.4323° E Yengi-sar, 1515 m R. Schultz 2004.09.03-086" and " Holotype Formica tarimica Seifert & Schultz " / " Paratype Formica tarimica Seifert & Schultz ", SMN Görlitz; from the same nest series: 3 mounted paratype workers and 48 paratype workers in ethanol, coll. RS.

Material examined: 34 samples with 126 workers from Tarim Basin (China) were subject to a numeric character analysis (Fig. 15). For details, see Appendix, as digital supplementary material to this article, at the journal's web pages.

Description of worker (Tab. 2, Fig. 7): small Servi-formica species (CS 1.242 mm), head elongated (CL / CW1.4 1.158), scape moderately long (SL / CS1.4 1.070), has the smallest eyes and the narrowest petiole within the F. rufi-barbis group (EYE / CS1.4 0.281, PEW / CS1.4 0.395). Clypeus with sharp median keel and fine longitudinal micro-carinulae. Frontal triangle finely transversely rippled and with 30 - 50 short pubescence hairs. Eyes with microsetae of 7 - 10 μ m maximum length. Total mean of unilateral setae numbers on different body parts predicted for a specimen with CS = 1.4 mm: pronotum 12.8, mesonotum 3.2, propodeum plus dorsolateral metapleuron 0.4, petiole dorsal of the spiracle 1.2, flexor profile of hind tibia 0.8, underside of head 0.0. Dorsal mesonotum in lateral aspect broadly convex. Metanotal depression relatively deep. Propodeal dome in profile rounded or angulate-convex. Dorsal crest of petiole in frontal view convex or bluntly angled. Petiole scale in lateral aspect thicker than in other species of the F. rufibarbis group, except F. orangea sp. n., with convex anterior and straight to slightly convex posterior profile. Gaster with transverse microripples of the largest average distance found in the F. rufibarbis (RipD 7.9 μ m) and covered by dense silvery pubescence (sqPDG 3.2). Pubescence on head, mesosoma and petiole less dense. Whole head, me-sosoma, coxae, all appendages, and petiole in typical cases reddish yellow, gaster always brown.

Comments on taxonomy: Seeing this orange species walking on the ground of dry steppe or semidesert habitats, F. tarimica sp. n. could be mistaken on the first glance for F. orangea sp. n. but the former is easily distinguished by the much more numerous pronotal setae and longer head. The separation of F. tarimica sp. n. from the other species with similarly large pronotal setae numbers, F. rufibarbis and F. anatolica sp. n., is shown in Figure 15: 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 any of the 111 nest samples of these three species with p> 0.975 and 0% error indication in a LOOCV-DA.

34 samples with 126 workers were subject to a numeric character analysis of 18 characters. China: Iminqäk, 9.IX.2004 [41.241° N, 84.436° E]; Iminqäk, 10.IX.2004 [41.230° N, 84.448° E] ; Iminqäk, 10.IX.2004 [41.233° N, 84.445° E] ; Iminqäk, 13.IX.2004 [41.208° N, 84.383° E] ; Korla (3 samples, No. 114, 116, 117), 8.IX.2004 [41.817° N, 86.188° E] ; road 218, 4.IX.2004 [41.006° N, 86.676° E] ; Shahyar , 15.VII.2006 [40.948° N, 82.879° E] ; Shahyar , 15.VII.2006 [40.952° N, 82.869° E] ; Yengisar (2 samples, No. 85, 86: type), 3.IX.2004 [42.125° N, 84.432° E] ; Yengisar (2 samples, No. 93a, 94), 3.IX.2004 [41.974° N, 84.491° E] ; Yengisar , 3.IX.2004 [41.974° N, 84.490° E] ; Yengisar , 3. IX.2004 [42.125° N, 84.431° E] ; Yengisar , 3.IX.2004 [42.125° N, 84.433° E] ; Yengisar , 9.IX.2004 [41.958° N, 84.677° E] ; Yingbazar , 29.VIII.2004 [41.177° N, 84.223° E] ; Yingbazar , 29.VIII.2004 [41.189° N, 84.264° E] ; Yingbazar , 29. VIII.2004 [41.194° N, 84.261° E] ; Yingbazar , 31.VIII.2004 [41.168° N, 84.224° E] ; Yingbazar , 31.VIII.2004 [41.169° N, 84.225° E] ; Yingbazar (3 samples, No. 65, 66c, 67), 31.VIII.2004 [41.173° N, 84.228° E] ; Yingbazar , 1.IX.2004 [41.166° N, 84.204° E] ; Yingbazar , 1.IX.2004 [41.168° N, 84.210° E] ; Yingbazar , 1.IX.2004 [41.177° N, 84.234° E] ; Yingbazar , VIII.2004 [41.173° N, 84.229° E] ; Yingbazar (2 samples, No. 1, 5), 12.IX.2006 [41.175° N, 84.231° E] ; Yuli , 8.IX. 2004 [41.342° N, 86.269° E] ; Yuli , 8.IX.2004 [41.342° N, 86.270°] .

Distribution and biology: A Central Asian species, apparently restricted to the Tarim Basin and adjacent foothills of the Tian Shan Mountains at elevations between 850 and 1550 m. Perhaps due to rarity of competing Formica species it occupies a diversity of habitats including semi-desert, pastures, irrigated crop plantations, gardens, open alluvial sand banks, and poplar or tamarisk stands. As a rule, the habitats are found on water-influenced ground, frequently near the Tarim River. Nests in moderately dry sand, often with characteristic slant gateways leading to the underground. Change of nest sites after inundation once observed. Foraging on poplars, probably tending trophobionts.