Tetramorium exile Csoesz & Radchenko

Csösz S., Radchenko, A. & Schulz, A., 2007, Taxonomic revision of the Palaearctic Tetramorium chefketi species complex (Hymenoptera: Formicidae)., Zootaxa 1405, pp. 1-38 : 1

5. Tetramorium exile Csoesz & Radchenko New species (figs 39-42)

Description of Worker (figs 39-42). Morphometric data of the holotype worker: CL: 725; CW: 675; FR: 240; FL: 240; SL: 585; ML: 790; MW: 440; PEW: 215; PEH: 240; NOH: 130; NOL: 130; PEL: 155; PPW: 240; PPL: 160; PPH: 210; SPL: 90; SPSP: 130; EL: 135; EH: 100; ED: 170; Small size, CS 695 [620, 743]. Whole body and appendages brown to dark brown. Head elongated, CL/CW 1.06 [1.04, 1.08], with very feebly convex sides, straight occipital margin and narrowly rounded occipital corners. Eyes small, EYE 0.167 [0.158, 0.175]. Frons very narrow, FR/CS 0.34 [0.33, 0.35], frontal lobes as wide as frons, FL/FR 1.0 [1.0, 1.02]. Scape very long, SL/CS 0.84 [0.82, 0.85], without longitudinal dorsal carina basally, smooth and shiny. Promesonotal dorsum slightly convex, metanotal groove very shallow or completely absent. Propodeal teeth moderately long and acute, directed mainly upwards. Petiolar node trapezoidal in profile, NOH/NOL 1.04 [0.90, 1.16], petiole relatively high, PEH/NOL 1.83 [1.70, 1.96]. General appearance moderately rugose, ground surface microreticulate, dull. Head dorsum longitudinally rugose, ground surface microreticulate, occiput rugoso-reticulate. Alitrunk dorsum and petiolar node rugoso-reticulate ground surface microreticulate, mesopleuron usually rugulose and microreticulate, dorsum of postpetiole longitudinally rugulose and microreticulate. Polygonal striation continuous on 1st gastral tergite (see fig. 8.). Ventral surface of head with several short and few moderately long, straight setae arising posterior to buccal cavity (see fig. 5.).

Gynes and Males are unknown.

Material examined: HOLOTYPE [[worker]]: AFGHANISTAN - O-Afghanistan, Walang, 2520m, Salangtal, Hindukusch , 29.09.1952. leg. J. Klapperich ( HNHM) ; PARATYPES: 35 [[workers]] from the same nest (3[[workers]] / HNHM, 4[[workers]] / MIZ, 25[[workers]] / NHMW 1[[worker]] / PCAS) .

Morphometrics: (33 workers were measured).

Diagnosis. According to the literature ( Collingwood 1961 a, 1961 b, Pisarski 1967a, 1967 b, 1969) and collection materials there are no similar Tetramorium species, described from Afghanistan. Workers of T. exile n. sp. differ from related species by absence of psammophore, relatively small eyes, (EYE, Table 1.), extremely narrow firons, the very long and smooth scape (FR/CS and SL/CS, Table 1.), and by the trapezoidal petiolar node (NOH/NOL and PEH/NOL, Table 1.). Tetramorium exile n. sp. is mostly similar to T. anatolicum sp.n. and T. chefketi , but differs from the latter by the shape of petiolar node: in T. exile n. sp. it is relatively high and short, trapezoidal in profile, while in T. chefketi it is relatively low and longer, cubic in profile, (PEH/NOL and NOH/NOL, Table 1.). The following Discriminant D(3a) function proves the separation between T. exile n. sp. and T. chefketi : D(3a) = 0.052 PPW -0.057 FL -0.081 NOL +14.667, T. exile n. sp. D(3a) = +3.418 ±0.901 [+2.169, +4.756] (n=33), T. exile n. sp., holotype D(3a) = +3.023, p<0.001, T. anatolicum n. sp. D(3a) = +3.164 ±0.796 [+1.746, +4.606] (n=38), T. anatolicum n. sp., holotype D(3a) = +3.246, p<0.001, T. chefketi D(3a) = -3.417 ±1.004 [-5.680, -0.524] (n=107), T. chefketi lectotype D(3a) = -4.179, p<0.001; T. sarkissiani lectotype D(3a) = -2.809, p<0.001; T. turcomanicum syntype worker D(3a) = -4.169, p<0.001.

T. exile n. sp. differs from T. anatolicum n. sp. by its longer scape and narrower firons (SL/CS and FR/CS, Table 1.). The following Discriminant D(2a) function provides the separation between T. exile n. sp. and T. anatolicum n. sp.: D(2a) = 0.081 SL - 0.151 FL - 7.652

T. exile n. sp. D(2a) = +2.683 ±0.762 [+1.193, +3.493] (n=33), T. exile n. sp., holotype D(2a) = +3.493, p<0.001, T. anatolicum n. sp. D(2a) = -2.683 ±1.064 [-4.682, -0.042] (n=38), T. anatolicum n. sp., holotype D(2a) = -3.117, p<0.001.

For further combination of morphometric characters see Table 1-2.

Distribution. Known from the type locality only.

Etymology. This adjective [exilis / -e; exile (neutrum) = slender] refers to the elongate body of this species.