Tetramorium aegeum

Nothing is known about the biology of . It is only know from the type material.

Identification
A member of the Tetramorium ferox species complex in the Tetramorium caespitum species group. Csösz and Schulz (2010) - Workers and gynes of T. aegeum  can be confused with those of Tetramorium diomedeum. Both species are less sculptured than relatives in the complex. The head and mesosoma are frequently smooth and shiny, but the imbricate first gastral tergite of T. aegeum is unique within this group. We had only a few samples of T. aegeum, so intraspecific variation is poorly known. A discriminant function using various morphological measurements is also defined and detailed.

Distribution based on Regional Taxon Lists
Palaearctic Region: Azerbaijan, Russian Federation.

Nomenclature

 * laevigatum. Tetramorium inerme subsp. laevigatum Arnol'di, 1948: 211 (w.q.m.) CAUCASUS. [First available use of Tetramorium caespitum subsp. ferox var. levigata Karavaiev, 1926c: 167; unavailable name.] [Junior primary homonym of laevigatum Mayr, above.] First available replacement name: aegeum Radchenko, 1992b: 55; designated by Bolton, 1995b: 403. [Note that a previously proposed replacement name for the unavailable levigata Karavaiev, aequa Baroni Urbani, 1971b: 361, is itself unavailable.] See also: Radchenko & Arakelian, 1990: 376.
 *  aegeum. Tetramorium aegea Radchenko, 1992b: 55 (w.q.m.) CAUCASUS. First available replacement name for laevigatum Arnol'di, 1948: 211 [Junior primary homonym of laevigatum Mayr, 1901b: 25.]; designated by Bolton, 1995b: 403. See also: Csösz & Schulz, 2010: 12.

Worker
Csösz and Schulz (2010) - Small size, CS 683 [648, 710]. Whole body and appendages yellow. Head slightly longer than broad, CL/CW 1.04 [1.03, 1.06], with feebly convex sides, straight posterior margin of the head with widely rounded corners. Eyes large, EYE 0.18 [-]. Frons wide, FR/CS 0.40 [0.40, 0.41], frontal lobes as wide as the frons, FL/FR 1.00 [-]. Scape short, SL/CS 0.75 [-], without dorso-basal carina, surface smooth and shiny. Promesonotal dorsum slightly convex, metanotal groove shallow. Propodeal denticles very short. Dorsal surface of petiole rounded, petiolar node higher than long, seen in profile NOH/NOL 1.09 [1.04, 1.12].

Head dorsum, posterior head surface, mesosoma dorsum, petiolar node and postpetiole smooth and shiny, ground surface smooth and shiny, or finely microreticulate. First gastral tergite imbricate. Ventral surface of head with a row of short setae and long C-shape hairs arising just posteriorly to buccal cavity forming a psammophore.

Queen
Csösz and Schulz (2010) - Small size, CS 864 [858, 870]. Head distinctly broader than long, CL/CW 0.90 [0.89, 0.91], with straight, sub-parallel sides, straight posterior margin with rounded corners. Frons wide, FR/CS 0.44 [-]. Scape short, SL/CS 0.70 [0.70, 0.71]. Head as wide as scutum, MW/CS 0.98 [0.97, 0.99]. Propodeal denticles short. Petiole and postpetiole wide, CS/PEW 1.62 [1.55, 1.68], CS/PPW 1.35 [-].

Whole body and appendages yellow. General appearance of head and mesosoma very feebly sculptured, surface smooth, appears shiny. Frons and genae with very fine longitudinal rugulae, or completely smooth, rest of head smooth. Scutum, scutellum, and anepisternum smooth and shiny, ventral part of katepisternum always smooth and shiny. Petiolar node and postpetiole feebly microreticulate, or smooth and shiny. First gastral tergite imbricate. Ventral surface of head with a row of short setae and long C-shape hairs arising just posteriorly to buccal cavity forming a psammophore.

Male
Csösz and Schulz (2010) - Head sides feebly convex, posterior margin widely rounded. Scutum broader than head. Propodeal denticles reduced, propodeum rounded in profile. Dorsum of petiolar node without a continuous transverse crest, dorsolaterally sharp and angulate. Whole body and appendages light brown. Head finely rugulo-reticulate, between main sulpturation microreticulate. Scutum, scutellum, anepi- and katepisternum finely rugulose, and smooth in part. Petiole and postpetiole finely rugulo-reticulate, between main sculpturation microreticulate.

Type Material
Csösz and Schulz (2010) - In the original description (Karawajew, 1926: 169) the following designation was given for the type material: “Tal des Pir-sagat (Gouv. Baku) 18.V.1907., Kaznakow und Schelkownikow (w, q, m)” without indication of the series number. The syntype material examined by us had no indication for the locality. This makes the status of our syntype material doubtful, but the lack of other available material and the fact that this series is deposited in the original Karawajew collection led us to treat the above series as syntype material.

References based on Global Ant Biodiversity Informatics

 * Borowiec L. 2014. Catalogue of ants of Europe, the Mediterranean Basin and adjacent regions (Hymenoptera: Formicidae). Genus (Wroclaw) 25(1-2): 1-340.
 * Csősz S., and A. Schulz. 2010. A taxonomic review of the Palaearctic Tetramorium ferox species-complex (Hymenoptera, Formicidae). Zootaxa 2401: 1-29.