Tetramorium poweri

Identification
A member of the Tetramorium simillimum species group.

Bolton (1980) - A very distinctive species within the poweri-complex which is characterized by reduced or vestigial frontal carinae and antennal scrobes, T. poweri is distinguished by its relatively small eyes and predominantly unsculptured cephalic dorsum. The lack of sculpture on the head is paralleled in the related Tetramorium pauper, but here the eyes are very small (maximum diameter only 0.13-0.15 x HW) and that species is smaller and has longer antennal scapes (HW 0.48-0.52, SI 76-83).

Distribution based on Regional Taxon Lists
Afrotropical Region: South Africa.

Nomenclature

 *  poweri. Tetramorium simillimum var. poweri Forel, 1914d: 225 (w.) SOUTH AFRICA. Raised to species: Bolton, 1980: 317.

Worker
Bolton (1980) - TL 2.6-2.8, HL 0.66-0.70, HW 0.56-0.58, CI 83-85, SL 0.50-0.52, SI 86-89, PW 0.40-0.42, AL 0.76-0.80 (6 measured).

Mandibles smooth with scattered pits or at most with faint vestiges of sculpture. Anterior clypeal margin entire, without trace of a median notch and with the median carina sharply defined. Frontal carinae vestigial or absent, sometimes ending in front of the level of the anterior margins of the eyes but more commonly extended back to beyond eye-level by a pair of extremely faint lines which are very poorly defined, these lines never reaching the occipital region. Antennal scrobes absent. Eyes small, maximum diameter 0.12-0.13, about 0.21-0.22 x HW and with 6-8 ommatidia in the longest row. Propodeum armed with a pair of minute denticles which are shorter and much narrower than the metapleural lobes. Node of petiole in profile broader than long. Sculpture very reduced. Dorsum of head usually with a couple of extremely feeble rugulae close to the vestigial frontal carinae on each side, but the occipital region and the mid-dorsal longitudinal strip unsculptured. Dorsal alitrunk unsculptured except for the weak lateral marginations and vestigial superficial shagreening, the latter strongest on the propodeum and almost effaced on the pronotum. Dorsal surfaces of petiole, postpetiole and gaster unsculptured or the pedicel segments with vestigial shagreening as on the pronotum. All dorsal surfaces of head and body with sparse short, stout blunt hairs, the tibiae of the middle and hind legs with minute appressed pubescence only. Colour uniform dull yellowish brown, the gaster usually slightly darker in shade.

Type Material
Bolton (1980) - Syntype workers, SOUTH AFRICA: Kimberley, 1912 (Power) [examined].

References based on Global Ant Biodiversity Informatics

 * Arnold G. 1917. A monograph of the Formicidae of South Africa. Part III. Myrmicinae. Annals of the South African Museum. 14: 271-402.
 * Bolton B. 1980. The ant tribe Tetramoriini (Hymenoptera: Formicidae). The genus Tetramorium Mayr in the Ethiopian zoogeographical region. Bulletin of the British Museum (Natural History). Entomology 40: 193-384.
 * Forel A. 1914. Formicides d'Afrique et d'Amérique nouveaux ou peu connus. Bulletin de la Société Vaudoise des Sciences Naturelles 50: 211-288.
 * Wheeler W. M. 1922. Ants of the American Museum Congo expedition. A contribution to the myrmecology of Africa. VIII. A synonymic list of the ants of the Ethiopian region. Bulletin of the American Museum of Natural History 45: 711-1004