Monomorium vatranum

Well collected in the Namib Desert.

Identification
A member of the viator-complex. A small darkly coloured species.

Distribution based on Regional Taxon Lists
Afrotropical Region: Namibia.

Nomenclature

 *  vatranum. Monomorium vatranum Bolton, 1987: 362, fig. 55 (w.) NAMIBIA.

Worker
TL 2.8, HL 0.71, HW 0.52, CI 73, SL 0.60, SI 115, PW 0.34, AL 0.80.

Holotype. Median portion of clypeus with its anterior margin shallowly convex. With the head in full-face view the sides in front of the eyes roughly parallel, behind the eyes weakly converging posteriorly. Occipital margin broadly and very shallowly concave. Maximum diameter of eye 0.27 x HW and with 9 ommatidia in the longest row. Scapes long, SI > 110. Alitrunk in profile with promesonotum low and only very shallowly convex, the metanotal groove not or only vestigially impressed. Dorsum of head with 3 pairs of hairs straddling the midline behind the level of the frontal lobes, without hairs close to the occipital corners. Dorsal alitrunk with a single pair of hairs, situated at the pronotal humeri. Petiole and postpetiole each with a single pair of backward directed hairs. First gastral tergite with hairs sparsely but more or less evenly distributed over the selerite in front of the apical transverse row. Cephalic dorsum with superficial reticular patterning, which may appear feebly shagreenate close to the occipital margin. Pronotal dorsum finely and densely reticulate, the sculpture becoming more sharply defined posteriorly on the alitrunk so that the propodeum is shallowly reticulate-punctulate. First gastral tergite smooth and shining, with superficial reticulate patterning only. Colour a uniform very dark brown.

Paratypes. TL 2.7-3.0, HL 0.62-0.74, HW 0.45-0.56, CI 72-76, SL 0.53-0.63, SI 113-120, PW 0.34-0.36, AL 0.76-0.82 (12 measured). Maximum diameter of eye 0.27-0.29 x HW, with 9-10 ommatidia in the longest row. As holotype but colour varying from medium brown to blackish brown, the colour usually uniform but sometimes the alitrunk slightly lighter than the head and gaster.

Type Material
Holotype worker, Namibia: Namib Desert, Swartbank 14°50' E, 23°16' S, sample S8, 15.vii.1981 (A. C. Marsh). Paratypes, 11 workers with same data as holotype; 3 workers, Namib Desert, Ganab, 15°37' E, 23°08' S, sample 98, sandy plain, 16.viii.1981 (A. C. Marsh); 3 workers with same data as last but sample G24, 5.v.1981; 3 workers with same data but sample 187, 19.viii.1981; 1 worker, Namib Desert, Mirabeb, 15°24' E, 23° 25' S, sample M13, 8.iv.1982 (A. C. Marsh) (BMNH; ; ).