Tetramorium argenteopilosum

Identification
A member of the Tetramorium simillimum species group.

Bolton (1980) - Amongst the four dark-coloured species of the oculatum-complex Tetramorium oculatum itself is isolated by its enormous eyes (0.37-0.39 x HW as opposed to 0.29-0.31 x HW in the three other species). In Tetramorium bevisi and Tetramorium krynitum the base of the first gastral tergite is unsculptured and the hairs on the tergite are not silvery and glittering, whereas in T. argenteopilosum gastral sculpture is very distinctive and the thick silvery hairs conspicuous. Finally, in both T. bevisi and T. krynitum the entirety of the promesonotum has rugular sculpture present whereas in T. argenteopilosum rugulae are restricted to the anterior pronotum, the remainder of the alitrunk being without them and strongly reticulate-punctate.

Distribution based on Regional Taxon Lists
Afrotropical Region: Zimbabwe.

Nomenclature

 *  argenteopilosum. Tetramorium argenteopilosum Arnold, 1926: 261, fig. 71 (w.q.) ZIMBABWE. See also: Bolton, 1980: 306.

Worker
Bolton (1980) - TL 2.9-3.2, HL 0.70-0.78, HW 0.63-0.70, CI 87-92, SL 0.44-0.50, SI 69-74, PW 0.46-0.52, AL 0.80-0.90 (11 measured).

Mandibles finely longitudinally striate and glossy, the sculpture reduced in a few individuals but still easily visible. Anterior clypeal margin entire, without a median impression. Frontal carinae weakly developed, narrow, scarcely stronger than the longitudinal rugulae of the cephalic dorsum, extending back beyond the level of the posterior margins of the eyes but usually fading out before reaching the occipital margin. Antennal scrobes feeble, merely a shallow impression in the sides of the head below the frontal carinae. Eyes large, maximum diameter 0.18-0.21, about 0.29-0.31 x HW, with 10-12 ommatidia in the longest row. Metanotal groove strongly impressed in profile, the propodeal dorsum convex immediately behind the groove but then grading into a shallowly concave slope down to the propodeal teeth. Propodeum armed with a pair of short triangular teeth which are roughly as long as their basal width in profile. In dorsal view each tooth shorter than half the distance separating their bases. Metapleural lobes reduced to low rounded flanges. Petiole in profile a high, fairly narrow node, the dorsal length less than the height of the tergal portion. In dorsal view the node much broader than long. Dorsum of head finely longitudinally rugulose, with about 12-14 rugulae between the frontal carinae at the level of the eyes. Spaces between the rugulae blanketed by a dense reticulate-puncturation which is very conspicuous. Dorsal alitrunk densely and strongly reticulate-punctate, with a few feeble rugulae on the anterior pronotum. Dorsal surfaces of petiole and postpetiole, and base of first gastral tergite reticulate-punctate. All dorsal surfaces of head and body with numerous elongate, stout hairs which are blunt apically; hairs silvery and glittering, especially on gaster. Middle and hind tibiae only with short appressed fine pubescence. Colour dark brown to blackish brown.

Type Material
Bolton (1980) - Syntype workers, female, RHODESIA: Umgusa River, Sawmills, 23.xi.1918 (G. Arnold) [examined].

References based on Global Ant Biodiversity Informatics

 * IZIKO South Africa Museum Collection