Monomorium viator

One of the commoner species in the Namib Desert desert areas where Marsh (1984) sampled.

Identification
Bolton (1987) - A very distinctive and conspicuous species of the Namib Desert, viator is rendered easily recognizable by its long scapes and relatively very large eyes, coupled with its lack of standing hairs on the alitrunk.

Distribution based on Regional Taxon Lists
Afrotropical Region: Namibia.

Nomenclature

 *  viator. Monomorium (Xeromyrmex) viator Santschi, 1923e: 280, fig. 3 (w.m.) NAMIBIA. See also: Bolton, 1987: 363.

Worker
Bolton (1987) - TL 3.0-3.7, HL 0.80-0.96, HW 0.58-0.72, CI 73-77, SL 0.68-0.86, SI 111-119, PW 0.38-0.46, AL 0.92-1.12 (15 measured).

Median portion of anterior dypeal margin transverse to shallowly concave. Eyes relatively very large, the maximum diameter 0.37-0.40 x HW, with 13-15 ommatidia in the longest row. Promesonotal dorsum evenly convex and sloping posteriorly to the very feebly impressed metanotal groove, in some workers the groove virtually unimpressed. Propodeal dorsum flat to shallowly transversely concave. Dorsum of head with 2-3 pairs of standing hairs straddling the midline behind the level of the frontal lobes. Dorsal alitrunk without hairs. Petiole with one pair and postpetiole with 1-2 pairs of backward directed hairs. First gastral tergite with hairs present in front of the apical transverse row, relatively few in number but more or less evenly distributed over the sderite; often with a tendency to be more concentrated on the basal half. Dorsum of head finely and densely reticulate to reticulate-shagreenate. Dorsal alitrunk reticulate to punctulate-granular on the pronotum, the sculpture generally becoming coarser and more conspicuous posteriorly but sometimes more or less even on the entire surface. First gastral tergite glossy and with superficial reticular patterning. Head and gaster usually darker in colour than the alitrunk. Alitrunk varying from yellowish orange to reddish brown, the head and gaster proportionally darker, ranging from light reddish to dark brown, with or without a reddish tint. In some the head may be bicoloured, with the posterior half lighter in shade than the anterior. Clypeus, mandibles and appendages are frequently dull yellow.

Type Material
Bolton (1987) - Syntype workers, male, Namibia: Namsen, 22.xii.1925 (R. W. E. Tucker) [examined].

Determination Clarifications
Bolton (1987) - This is the species referred to by Marsh (1984) as Monomorium sp. A in his Namib Desert pitfall studies.