Tetramorium chefketi

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

Definition of the T. chefketi species complex

Species belonging to the T. chefketi species complex can be defined by the following combination of characters:

Workers

a) polygonal striae are continuous on 1st gastral tergite, and is sometimes microreticulate basally. Polygonal striation: interstices marked by feeble anastomosing striae (Fig. 8.), compare to microreticulation: interstices marked by very feeble elevated structures, like rugulae (Fig. 6, 7.);

b) head, alitrunk and waist coarsely sculptured, dorsum of petiolar node and postpetiole coarsely rugose and/ or reticulate.

c) petiole and postpetiole relatively narrow (CS/PEW and CS/PPW, Table 1);

d) ground surface on the frons is usually coarsely microreticulate;

Gynes

e) alitrunk is low, dorsum is flattened in profile;

f) scutum in dorsal view is somewhat narrowed anteriorly and does not cover completely the pronotum, humeri are well visible;

g) head, alitrunk and waist are coarsely sculptured, and petiole and postpetiole dorsum coarsely rugose or/ and reticulate;

h) polygonal striae disrupted on 1st first gastral tergite, sometimes microreticulate basally;

i) mandibles are longitudinally striate; j) petiole and postpetiole are relatively narrow (WAIST, Table 2);

Males

k) head and alitrunk with usually coarsely sculpture, ground surface microreticulate;

l) sides of petiole and postpetiole not angulate as in the ferox species complex (in dorsal view);

m) first gastral tergite usually smooth and shiny, or feebly striate;

n) stipes of genitalia blunt, curved inwards at the top, with flattened apical plate (in caudal view);

We placed the following species into the chefketi species complex:

1) Tetramorium alternans Santschi, 1929

Tetramorium biskrensis kahenae Menozzi, 1934 new synonymy

2) Tetramorium anatolicum Csoesz & Schulz , new species

3) Tetramorium annectens Pisarski, 1969 status revised

4) Tetramorium chefketi Forel, 1911

Tetramorium caespitum var. sarkissiani Forel, 1911 new synonymy

Tetramorium turcomanicum Santschi, 1921 new synonymy

Tetramorium taurocaucasicum Arnoldi, 1968 new synonymy

Tetramorium forte Forel, 1904 [in part, only material from Crimea and Caucasus] (for details of clarification of synonymy see Taxonomic notes under Tetramorium chefketi )

5) Tetramorium exile Csoesz & Radchenko , new species

6) Tetramorium moravicum Kratochvil, 1941

Tetramorium rhenanum Schulz, 1996

7) Tetramorium rhodium Emery, 1922 status revised

8) Tetramorium sanetrai Schulz & Csoesz , new species

9) Tetramorium sulcinode Santschi, 1927 status revised

Tetramorium karakalense Dlussky & Zabelin, 1985 new synonymy

10) Tetramorium syriacum Emery, 1922

The newly defined chefketi species complex may not strictly reflect the phylogenetic relationship of the above-mentioned species. T. sulcinode and T. annectens possess several autapomorphic characters (e.g. relatively large eyes and a long psammophore) what probably may lead to place them into a separate group in a future.

Key to the species of the Tetramorium chefketi species complex

Workers

1. Ventral surface of head with a row of short and several very long setae, forming a psammophore (figs 3, 4) [sometimes setae can be broken or lost]. Eyes larger, EYE = 0.185 ...................................................2

- Ventral surface of head with several short and a few longer straight setae, psammophore not developed (fig. 5). Eyes smaller, EYE <0.185..........................................................................................................3

2(1). Dorsum of petiolar node and postpetiole with sinuous rugae and coarse irregular reticulation. Ground surface microreticulate. Petiole much narrower than postpetiole, PEW/PPW 0.73 [0.70, 0.75] (China and Mongolia) ............................................................................................. T. annectens Pisarski, 1969

- Dorsum of petiolar node usually with semi-circular rugulae, ground surface smooth and shiny, postpetiole longitudinally rugulose, and shiny. Petiole slightly narrower than postpetiole, PEW/PPW 0.84 [0,80; 0,88] (Afghanistan, Pakistan and Turkmenistan) ............................. T. sulcinode Santschi, 1927

3(1). Frons extremely wide FR/CS 0.50 [0.49, 0.54] (Middle East) ....................... T. syriacum Emery, 1922

- Frons narrower FR/CS <0.41..................................................................................................................4

4(3). Scape shorter, SL/CS = 0.75.....................................................................................................................5

- Scape longer, SL/CS = 0.76......................................................................................................................7

5(4). Dorsal surface of petiole steeply rounded backward, NOH/NOL 1.03 [0.94, 1.13] petiole relatively high, PEH/NOL 1.84 [1.68, 2.04]. Dorsum of petiolar node and postpetiole with very feeble concentric sinuous rugulae and reticulation, medially microreticulate. D(2b) 0.093 FR - 0.148 NOL - 2.941 = +2.647 [+1.069, +4.647] (NW Africa) ..................................................................... T. alternans Santschi, 1929

- Petiolar node cubic in profile, NOH/NOL 0.84 [0.76, 0.97], petiole relatively low and long, PEH/NOL 1.50 [1.38, 1.73]. Dorsum of petiolar node and postpetiole coarsely rugoso-reticulate. D(2b) 0.093 FR - 0.148 NOL - 2.941 <+0.369 [-4.206, +0.369] ....................................................................................... 6

6(5) Head dorsum and alitrunk coarsely rugoso-reticulate, ground surface coarsely microreticulate. Scape feebly costulate, first gastral tergite microreticulate. D(3b) 0.118 MW - 0.121 PEH - 0.084 PPH - 4.585 = +2.643 [-0.619, +4.595] (Asia Minor, Rhodes and Cyprus)......................... T. rhodium Emery, 1922

- Head dorsum and alitrunk feebly rugoso-reticulate, ground surface feebly microreticulate. Scape always smooth, first gastral tergite never microreticulate but well polygonally striate. D(3b) 0.118 MW - 0.121 PEH - 0.084 PPH - 4.585 = -2.643 [-4.022, -0.882] (Italy) ..... T. sanetrai Schulz & Csoesz n. sp.

7(4). Base of scape with well visible dorsal carina, elongate ridge and costulae extending whole scape length (fig. 49) (Central and East Europe, SE France and NW Italy, Caucasus, and Asia Minor)....................... ............................................................................................................... T. moravicum Kratochvil, 1941

- Base of scape without dorsal carina, surface not costulate, smooth and shiny at least basally (figs 24, 38 and 42; see also figs 17, 31, 60 and 67) ..................................................................................................8

8(7). Petiolar node cubic in profile, NOH/NOL 0.86 [0.76, 0.97], petiole relatively low and long, PEH/NOL 1.53 [1.37, 1.69] (fig. 37) (Eastern part of South Europe to Kyrgyzstan) ........... T. chefketi Forel, 1911

- Petiolar node trapezoidal in profile, NOH/NOL = 0.96, petiole relatively high, PEH/NOL> 1.74 (figs 23 and 40).................................................................................................................................................9

9(8) Dorsum of alitrunk rugoso-reticulate, ground surface microreticulate (fig. 39). Scape long, SL/CS 0.82 [0.82, 0.85], frons narrow, FR/CS 0.34 [0.33, 0.35], frontal lobes as wide as frons, FL/FR 1.0 [1.0, 1.02]. D(2a) 0.081 SL - 0.151 FL - 7.652 = +2.683 [+1.193, +3.493]. (Afghanistan) ............................... .......................................................................................................... T. exile Csoesz & Radchenko n. sp.

- Dorsum of alitrunk with parallel rugulae, ground surface feebly microreticulate (fig. 22). Scape shorter, SL/CS 0.78 [0.76, 0.81], frons wider, FR/CS 0.37 [0.35, 0.39], frontal lobes wider, FL/FR 1.02 [1.0, 1.08]. D(2a) 0.081 SL - 0.151 FL - 7.652 = -2.683 [-4.682, -0.042]. (Anatolia, Turkey) .......................... ....................................................................................................... T. anatolicum Csoesz & Schulz n. sp.

Gynes (gynes of T. exile , T. rhodium , and T. syriacum are unknown)

1. Ventral surface of head with a row of short and several very long setae, forming a psammophore (in gynes this character is less distinct than in workers) ..............................................................................2

- Ventral surface of head with several short and a few straight, moderately long setae, psammophore absent ......................................................................................................................................................3

2(1). Dorsum of petiolar node and postpetiole with sinuous rugae and coarse irregular reticulation. Petiolar node relatively low, NOH/NOL 1.38, PEH/NOL 2.56 ............................... T. annectens Pisarski, 1969

- Dorsum of petiolar node usually with semi-circular rugulae, smooth medially, postpetiole longitudinally striate. Petiolar node relatively high, NOH/NOL 1.71 [1.52, 1.91], PEH/NOL 3.30 [3.12, 3.63] ... ...................................................................................................................... T. sulcinode Santschi, 1927

3(1). Dorsal crest of petiolar node slightly convex with a well visible protuberance medially in frontal view (fig 43.). Scape basally with a well visible dorsal carina, elongated costulae sometimes extending whole scape surface (fig 45.). Head slightly narrower than scutum, MW/CS 1.07 [1.05, 1.13] .......................... ............................................................................................................... T. moravicum KratochvIl, 1941

- Dorsal transversal crest of petiolar node straight, without protuberance medially (in frontal view). Scape basally without dorsal carina and without elongated costulae. Head wider than scutum, MW/CS <1.0 ........................................................................................................................................................4

4(3). Ventral part of katepisternum smooth and shiny. Petiolar node dorsum steeply rounded backward in profile ......................................................................................................................................................5

- Ventral part of katepisternum rugoso-reticulate and microreticulate. Petiolar node dorsum flattened in profile ......................................................................................................................................................6

5(4). Dorsum of petiolar node and postpetiole finely microreticulate, smooth medially. Scape shorter, SL/CS 0.69 [0.65, 0.71] ........................................................................................... T. alternans Santschi, 1929

- Dorsum of petiolar node and postpetiole reticulate and microreticulate. Scape longer SL/CS 0.75 [0.71, 0.77] ............................................................................................. T. anatolicum Csoesz & Schulz n. sp.

6(4). Whole dorsum of petiolar node and postpetiole coarsely rugose. Scape longer, SL/CS 0.77 [0.75, 0.79]. ............................................................................................................................... T. chefketi Forel, 1911

- Dorsum of petiolar node and postpetiole coarsely rugose, but medially smooth. Scape shorter, SL/CS 0.67 [0.66, 0.68] ................................................................................. T. sanetrai Schulz & Csoesz n. sp.