Tetramorium schneideri

Radchenko and Scupola (2015) - In contrast to the previous species, distributed mainly on plains and foothills, it prefers desert and semi-desert biotopes and is one of the commonest ant species in many places. Nests build in a soil, sometimes under stones. Consumes mainly plant seeds, but also collects living and dead small invertebrates. Nuptial flight is in May - early June (for more details see Zakharov, 1976; Dlussky, 1981; Dlussky et al., 1990).

Identification
Radchenko and Scupola (2015) - Preceding authors (e. g. Ruzsky, 1905 a, b; Dlussky et al., 1990) had separated Tetramorium striativentre and Tetramorium schneideri by the sculpture on the head dorsum and the length of the propodeal teeth. These features are normally useful, but occasionally they may be quite variable and sometimes single specimen of both species may be hardly distinguishable. The sculpture on the head dorsum in T. striativentre is generally coarser than in T. schneideri. The number of longitudinal rugae level with the eyes in the first species is 16–21 (mean 18) and 17–33 (mean 23) it the latter one; at the same time, the length of propodeal spines are rather variable in both species, despite they are generally shorter in T. striativentre (mean ESLI 0.10 with the range 0.05–0.18 vs. mean 0.19 with the range 0.15–0.25 in T. schneideri).

Radchenko (1992 a) added as an important feature for the separation of these species the shape of the petiolar node: transversal in T. striativentre (PndI > 1.20) and subcircle in T. schneideri (PndI < 1.15).

In the course of the current revision we paid an attention to one more very distinct feature never used before for the separation of T. striativentre and all other species with the completely striato-punctated first gastral tergite (e. g. T. schneideri, Tetramorium saudicum and Tetramorium sabatinellii): the frontal carinae in T. striativentre are not curved, gradually converging anteriorly so that the frontal lobes are not extended (FLI 1.00–1.06, mean 1.01), but in three other species the frontal carinae are curved above the antennal insertions and the frontal lobes are distinctly extended (FLI ≥ 1.08, means 1.12 … 1.17).

Finally, T. striativentre well differs from three above mentioned species by the more regular, longitudinally-concentric rugae on the dorsum of the petiolar node and postpetiole.

T. schneideri well differs from two other species with the completely sculptured first gastral tergite (Tetramorium saudicum and Tetramorium sabatinellii) first of all by the subcircle petiolar node (it is distinctly transversal in the latter species), and by the finer longitudinal rugosity on the head dorsum (number of rugae between the frontal carinae level with the eyes > 15, mean 23, same in the latter species < 15, means 12 … 13).

Distribution
Central Asia, southern Kazakhstan, Afghanistan, Iran.

Distribution based on Regional Taxon Lists
Palaearctic Region: Afghanistan, China, Iran, Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, Uzbekistan.

Nomenclature

 *  schneideri. Tetramorium schneideri Emery, 1898c: 145 (w.) KAZAKHSTAN. Subspecies of striativentre: Ruzsky, 1905a: 518; Ruzsky, 1905b: 767; Emery, 1909d: 706. Revived status as species: Dlussky & Zabelin, 1985: 232. Material of the unavailable name longispina referred here by Dlussky, Soyunov & Zabelin, 1990: 207.

Worker
Radchenko and Scupola (2015) - (n = 30), ordered as: min-max [mean +/- SD] (see also fig. 10, a–d) : HL 0.66–0.90 [0.83 +/- 0.055], HW 0.65–0.90 [0.81 +/- 0.065], FW 0.26–0.34 [0.31 +/- 0.022], FLW 0.30–0.39 [0.36 +/- 0.025], OL 0.14–0.23 [0.20 +/- 0.018], GnL 0.13–0.24 [0.19 +/- 0.028], SL 0.52–0.72 [0.65 +/- 0.056], ML 0.86–1.16 [1.05 +/- 0.075], PNW 0.40–0.57 [0.52 +/- 0.040], PL 0.32–0.46 [0.38 +/- 0.041], PW 0.19–0.27 [0.24 +/- 0.023], PH 0.22–0.32 [0.28 +/- 0.023], PndL 0.18–0.27 [0.23 +/- 0.020], PPL 0.20–0.26 [0.23 +/- 0.017], PPW 0.23–0.32 [0.28 +/- 0.023], PPH 0.23–0.31 [0.29 +/- 0.015], ESL 0.11–0.19 [0.15 +/- 0.018], ESD 0.17–0.26 [0.22 +/- 0.022], HTL 0.49–0.70 [0.64 +/- 0.020], rug-frons 17–33 [23 +/- 4.484].

Indices: CI 0.99–1.09 [1.02 +/- 0.028], SI1 0.71–0.83 [0.78 +/- 0.035], SI2 0.71–0.85 [0.80 +/- 0.035], FI 0.36–0.43 [0.38 +/- 0.017], FLI 1.09–1.23 [1.17 +/- 0.037], OI1 0.22–0.27 [0.24 +/- 0.005], OI2 0.91–1.23 [1.03 +/- 0.085], PI1 1.19–1.56 [1.36 +/- 0.090], PI2 0.25–0.31 [0.29 +/- 0.013], PndI 0.89–1.11 [1.02 +/- 0.065], PPI1 0.75–0.90 [0.81 +/- 0.039], PPI2 0.31–0.39 [0.35 +/- 0.021], ESLI 0.15–0.25 [0.19 +/- 0.026].

Queen
Radchenko and Scupola (2015) - HL 0.91, HW 0.96, FW 0.37, FLW 0.43, OL 0.25, GnL 0.19, SL 0.75, PL 0.53, PW 0.35, PH 0.49, PndL 0.25, PPL 0.25, PPW 0.43, PPH 0.37, ESL 0.11, ESD 0.35, HTL 0.72, ML 1.49, MH 0.74, SCL 1.03, SCW 0.85, rug-frons 27.

Indices: CI 0.95, SI1 0.82, SI2 0.78, FI 0.39, FLI 1.15, OI1 0.26, OI2 1.32, PI1 1.37, PI2 0.37, PndI 1.39, PPI1 0.59, PPI2 0.45, ESLI 0.11, MI 2.46, SCI 1.22.

Male
Radchenko and Scupola (2015) - 1 male, Uzbekistan, Kuldzhuktau, 9.05.1961 (ZMMU).

HL 0.61, HW 0.63, OL 0.26, GnL 0.04, SL 0.31, PL 0.443, PW 0.22, PH 0.22, PPL 0.24, PPW 0.36, PPH 0.32, HTL 0.83, ML 1.69, MH 0.94, SCL 1.20, SCW 0.94.

Indices: CI 0.96, SI1 0.51, SI2 0.49, OI1 0.42, OI2 6.00, PI1 2.00, PI2 0.35, PPI1 0.67, PPI2 0.58, MI 1.81, SCI 1.28.

Head somewhat wider than length, broadly rounded above eyes, occipital margin convex. Anterior clypeal margin slightly prominent medially. Eyes big, situated distinctly below midlength of sides of head, so that genae very short. Scape length about half of head width. Mandibles with five sharp teeth, apical one much longer than others. Sculpture of head dorsum quite coarse: frons and clypeus with longitudinal rugosity, surface between and behind lateral ocelli with transversal rugae, remaining part of head dorsum coarsely and densely punctated. Occipital margin and temples with not abundant, relatively short erect to suberect hairs.

Mesosoma very long and low, scutum and scutellum very feebly convex, forming with propodeum more or less regular arch, notauli well developed. Petiole very long and low, twice longer than height, with almost straight anterior face and very widely rounded node dorsum. Petiole quite narrow, its node subcircle (seen from above), postpetiole > 1.6 times wider than petiole. Scutum and scutellum finely and densely longitudinal ruguloso-striated, surface between rugulae finely, but densely punctated, lateral parts of dorsum of scutum smooth and shiny. Sides of mesosoma finely, but densely longitudinally striato-punctated. Petiolar node laterally with short longitudinal rugulae, its dorsum finely punctated, postpetole dorsally quite coarsely longitudinally rugose.

Stipites of genitalia very smoothly curved inward apically (seen dorsally or ventrally), their apices convex, not excavated (seen from behind).

Mesosoma and waist with sparse and quite short erect hairs. In contrast to known males of other species from striativentre-group, surface of first gastral tergite finely, but densely longitudinally striato-punctated (this sculpture is similar to that in workers and queens, but is much finer), remainder tergites with fine, but very obvious superficial microreticulation.

Body colour dark reddish-brown, clypeus, mandibles and appendages brownish-yellow.

Type Material
Worker, Uzbekistan.