Tetramorium rhodium

Identification
Csösz, Radchenko and Schulz (2007) - Workers of T. rhodium differ from related species by the lack of psammophore, relatively small eyes, very short and very feebly costulate scape, cubic petiolar node and moderately wide frons. Workers of T. rhodium mostly resemble those of, Tetramorium syriacum, Tetramorium sanetrai and Tetramorium chefketi. Workers of T. rhodium well differ from those of T. syriacum by their narrower frons, FR/CS, from those of T. chefketi by their shorter scape SL/CS. Tetramorium rhodium and T. sanetrai are very similar in both, general appearance and metric characters. For separation between T. rhodium and T. sanetrai see differential diagnosis of T. sanetrai.

Distribution based on Regional Taxon Lists
Palaearctic Region: Cyprus, Greece, Turkey.

Castes
Known only from the worker caste.

Nomenclature

 *  rhodium. Tetramorium caespitum var. rhodia Emery, 1924d: 277 (w.) GREECE. [First available use of Tetramorium caespitum subsp. caespitum var. rhodia Emery, 1915h: 3; unavailable name.] Subspecies of caespitum: Emery, 1925c: 179. Raised to species: Csösz, Radchenko & Schulz, 2007: 27.

Worker
Csösz, Radchenko and Schulz (2007) - Figs 50–53. Medium to large size, CS 832 [720, 895]. Whole body and appendages black. Head square, CL/CW 0.99 [0.98, 1.02], with somewhat convex sides, slightly concave occipital margin and rounded occipital corners. Eyes small, EYE 0.173 [0.163, 0.184]. Frons moderately wide, FR/CS 0.38 [0.36, 0.40], frontal lobe as wide as frons, FL/FR 1.0 [1.00, 1.02]. Scape short, SL/CS 0.73 [0.71, 0.75], with short dorsal carina basally, well visible parallel costulae extending scape. Promesonotal dorsum convex, metanotal groove shallow, but distinct. Propodeal teeth moderately long. Petiolar node cubic in profile, NOH/NOL 0.84 [0.76, 0.97], petiole relatively low, PEH/NOL 1.50 [1.38, 1.73]. General appearance coarsely rugose, ground surface coarsely microreticulate, dull. Head dorsum and occiput longitudinally rugose and coarsely microreticulate, its sides rugoso-reticulate and microreticulate. Alitrunk dorsum rugoso-reticulate and coarsely microreticulate, mesopleuron coarsely microreticulate. Dorsum of petiolar node rugoso-reticulate and microreticulate, dorsum of postpetiole longitudinally rugulose and microreticulate. Polygonal striation continuous on 1st gastral tergite, posteriorly disrupted. Basal part of first gastral tergite microreticulate (see fig. 7.), MRG 319.7 ±126.5 [50, 500]. Ventral surface of head with several short and moderately long, straight, or few C-shape setae arising posteriorly to buccal cavity (see fig. 5.).

Type Material
Csösz, Radchenko and Schulz (2007) - Syntype workers, “Rodes” [GREECE], “Kattabea”, “Tetr. caesp.”, “var. rhodia Emery” (2 worker;, 2 worker; )