Pristomyrmex cribrarius Arnold

Bolton, B., 1981, A revision of six minor genera of Myrmicinae (Hymenoptera: Formicidae) in the Ethiopian zoogeographical region., Bulletin of the British Museum (Natural History) Entomology 43, pp. 245-307 : 285

Pristomyrmex cribrarius Arnold

(Fig. 35)

Pristomyrmex cribrarius Arnold , 1926: 281, fig. 81. Holotype female, Mozambique: Amatongas Forest (G. Arnold) (NM, Bulawayo) [examined].

Worker. TL 3.2 - 3.4, HL 0.84 - 0.90, HW 0.86 - 0.92, CI 101 - 102, SL 0.66 - 0.72, SI 77 - 79, PW 0.56 - 0.60, AL 0.82 - 0.86 (3 measured).

Basal portions of mandibles rugulose but this fading out distally so that the area near the apical margin is mostly or entirely smooth. Apical (masticatory) margin of mandible with three teeth; apical and preapical tooth acute and roughly the same size, behind them is a long diastema followed by the broad and truncated basal tooth. The broad basal tooth may be the result of fusion of two denticles and specimens with a broad-based tooth but a bidenticulate crown must be expected. Clypeus with a strong sharp median longitudinal carina; anterior clypeal margin with a small truncated lobe medially where the carina meets the margin, this lobe flanked on each side by a few smaller denticles which are variable in number and shape. Palp formula 4, 3. Frontal carinae present and strongly divergent, reaching back to, or just beyond, the level of the posterior margins of the eyes. Below the frontal carinae to eye level is a short, weakly impressed scrobal area, bounded below by a weak genal carina which runs above the eye. Eyes large, maximum diameter 0.18 - 0.20, about 0.21 - 0.22 x HW and with 9 - 10 ommatidia in the longest row. With head in full-face view the occipital margin transverse to evenly very feebly concave, not indented medially. Pronotum armed with a pair of short but broad-based acute triangular teeth. Propodeum with a pair of long spines which are slightly sinuate along their length. Metapleural lobes small, bluntly triangular in shape. General shape of alitrunk and pedicel segments as in Fig. 35. Dorsum of head between frontal carinae and back to occipital margin densely covered with broad, shallow foveolate punctures which are much broader than the distances separating them. In places the foveolae are roughly aligned so that the cuticle separating them appears as rugular sculpture. Similar sculpture is present below, behind and in front of the eyes, but the scrobal area lacks such sculpture and the clypeus is unsculptured except for the strong median carina. Entirety of dorsal alitrunk with strongly developed but blunt rugae which are predominantly longitudinal. Sides of alitrunk rugulose. Sides and dorsum of petiole node with a few coarse longitudinal rugae. Sides of postpetiole with a few strong rugae, the tergite in profile bounded by a raised ridge or rim. In dorsal view the rim appearing as in Fig. 35, the space between the converging lines being smooth and shiny. Gaster unsculptured. Dorsal surfaces of head, alitrunk, petiole and postpetiole with abundant short erect to suberect hairs. Scapes and tibiae with similar freely projecting hairs and numerous hairs projecting from the sides of the head in full-face view. First gastral tergite without hairs. Colour brown, the gaster darker than the head and alitrunk but the appendages lighter.

This very distinctive species is apparently rare, being known only from the type-collection made in Mozambique and a short series from South Africa noted below. It is easily separable from all the other African Pristomyrmex by its dense pilosity, coarse sculpture, high palp formula and oddly shaped postpetiole.

Material examined South Africa: Natal, Dukuduku For. Res. (W. L. & D. E. Brown).