Ocymyrmex kahas

Identification
This distinctive species is characterized by its strong clypeal flange, eyes which break the outline of the sides of the head, PF 4,3, and unconstricted gastral base with both tergite and sternite convex basally in profile. At first glance it is reminiscent of Ocymyrmex barbiger, Ocymyrmex cilliei, Ocymyrmex robustior and Ocymyrmex dekerus, but all of these lack the very broad clypeal flange and have a strong median longitudinal impression or groove along the postpetiolar sternite. The closest relatives of kahas are Ocymyrmex afradu and Ocymyrmex flavescens, which share the characteristic clypeal and postpetiolar structure of kahas, and which together constitute the kahas-group. kahas and flavescens have the gaster yellowish, afradu has the gaster black; kahas and flavescens have the petiolar peduncle longer than the node whilst afradu has the node slightly longer than the peduncle. In full-face view the occipital margin is more strongly indented medially in afradu and flavescens than in kahas, and in afradu the petiole node is long, low and subclavate in profile. (Bolton and Marsh 1989)

Key to Ocymyrmex workers

Distribution based on Regional Taxon Lists
Afrotropical Region: Namibia.

Nomenclature

 *  kahas. Ocymyrmex kahas Bolton & Marsh, 1989: 1298, figs. 11, 16 (w.) NAMIBIA.

Worker
Holotype. TL 6.7, HL 1.72, HW 1.54, CI 90, SL 1.56, SI 101, PW 0.95, AL 2.00.

Anterior clypeal margin with a small notch medially. Margin of clypeus with a broad projecting cuticular flange. Palp formula 4,3. With the head in full-face view the outer curve of the eyes just breaking the outline of the sides of the head. Maximum diameter of eye 0.36, about 0.23 x HW. Sides of head in front of eyes more or less straight and very feebly divergent anteriorly. Behind the eyes the sides converging posteriorly and rounding into the relatively broad occipital margin; the latter very feebly indented medially. With alitrunk in profile the pronotum rising steeply from the cervical shield and only very shallowly convex dorsally. Propodeal dorsum feebly convex and rounding posteriorly into the weakly convex declivity. Bulla of metapleural gland not strongly projecting posteriorly, the narrow metapleural lobe and the carina linking the lobes across the declivity, clearly visible in profile. Petiole node in dorsal view about as broad as long, postpetiole slightly broader than long. Sternite of postpetiole ventrally shallowly and inconspicuously concave medially, lacking a deep median longitudinal impression or groove. In profile the outlines of the first gastral tergite and sternite are each shallowly convex from their articulation with the postpetiole. In dorsal view the base of the gaster is not constricted. Dorsum of head finely and densely longitudinally rugulose, the rugulae faint and feebly wavy to very weakly sinuate. Ground-sculpture between the rugulae faint and feeble, but the surface not glassy smooth. Dorsal alitrunk mostly densely and finely transversely rugose but with a patch of longitudinal sculpture between the mesothoracic spiracles. Sides of alitrunk with regularly spaced strong dense rugae, the spaces between which are wider than the rugae themselves. On the sides of the pronotum about 16 rugae are present between the base of the mesothoracic spiracle and the ventral margin of the sclerite. Ground-sculpture on sides of alitrunk superficial and minimal, so that the rugae stand out in sharp relief. Petiole and postpetiole mostly feebly reticulate, the petiole node with some extremely faint vestiges of transverse sculpture dorsally and with some stronger transverse rugulae ventrally. All dorsal surfaces of head and body with spaced out standing hairs present. Head a dull orange-red, the gaster more yellowish so that the gaster is somewhat lighter in shade than the head. Alitrunk darker, dull reddish to reddish brown.

Paratypes. TL 6.3-7.0, HL 1.64-1.74, HW 1.44-1.56, CI 87-91, SL 1.48-1.56, SI 100-104, PW 0.88-0.96, AL 1.88-2.00 (8 measured). Maximum diameter of eye 0.33-0.36, about 0.23-0.25 x HW. Sides of pro no tum with 13-16 rugae between base of mesothoracic spiracle and ventral margin. In some para types the cephalic rugular sculpture diverges more strongly posteriorly than in the holotype, and in these a small area of U-shaped rugular sculpture may occur centrally close to the occipital margin.

Type Material
Holotype worker, Namibia ( = South West Africa): Khorixas, 20 deg. 19 min. S., 14 deg. 57 min. E., 20.iii.1982, sample KHI (A.C. Marsh). Paratypes, 8 workers with same data as holotype (BMNH, SAM, ).