Pristomyrmex trogor, Bolton, B., 1981

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 : 287-288

Pristomyrmex trogor sp. n.

(Figs 33, 36)

Holotype worker. TL 4.0, HL 0.96, HW 0.99, CI 103, SL 100, SI 101, PW 0.61, AL 0.96.

Mandibles basally with some weak rugular sculpture but this fading out distally so that near the apical margin the blade is smooth. Apical (masticatory) margin with a large apical tooth followed by a slightly smaller preapical, a diastema and two basal denticles which arise at each end of a raised welt representing the fused bases of the two denticles (in worn specimens this would appear as a single broad truncated basal tooth). Median portion of clypeus without a longitudinal median carina except posteriorly where a vestige remains. Anterior clypeal margin with a small median tooth and a couple of smaller denticles on each side. Frontal carinae absent, the posterior extensions of the frontal lobes strongly divergent but short, fading out in front of the level of the anterior margins of the eyes. The genal carina which bounds the outer margin of each antennal fossa strong, curving in towards the extensions of the frontal lobes but not meeting them. Antennal scrobes absent, the scapes relatively long (SI, above). Eyes small, maximum diameter 015, about 0.15 x HW. With the head in full-face view the occipital margin indented medially, the sides shallowly but evenly convex. Pronotum armed with a pair of short triangular spines, propodeum with a pair of slightly larger spines; outline shape of alitrunk as in Fig. 33. Metapleural lobes fairly large, rounded. Dorsum of alitrunk flat to shallowly concave between the pronotal spines and between the lateral hair-bearing welts of the mesonotum. Petiole node high in profile, the dorsum sloping downwards posteriorly and rounding into the posterior face. Anterior and dorsal faces of postpetiole in profile forming a single evenly curved surface.

In dorsal view the petiole node about as long as broad, the postpetiole very slightly longer than broad and broadening from front to back. Entirety of head and body smooth and glossy, unsculptured except for a few ridges on the metapleuron leading up to the orifice of the metapleural glands. Dorsum of head with numerous fine curved hairs, some of which are very long. Mandibles, clypeal margin and ventral surface of head with equally dense but generally shorter fine hairs; similar hairs also present on anterior coxa. Alitrunk without hairs except for 2 pairs arising from the mesonotal welt. Petiole, postpetiole and first gastral tergite without hairs; apex of gaster and sternites behind the first with a few hairs present. Scapes and tibiae with short, fine, apically directed hairs. Colour uniform glossy chestnut-brown.

Paratype workers. TL 3.4 - 4.0, HL 0.88 - 0.96, HW 0.89 - 0.98, CI 101 - 103, SL 0.90 - 0.98, SI 100 - 102, PW 0.56 - 0.61, AL 0.86 - 0.98 (4 measured). Maximum diameter of eye 0.14 - 0.16, about 0.14 - 0.16 x HW. As holotype but some darker brown in colour.

Holotype worker, Zaire (B. Congo on data label): S. Slope of Mt Kahuzi, 1900 m, 5. ix. l 957 (E. S. Ross & R. E. Leech) (CAS, San Francisco).

Paratypes, 19 workers and 1 male with same data as holotype (BMNH; MCZ, Cambridge; CAS, San Francisco).

P. trogor is related to africanus , fossulatus , and orbiceps but is easily recognizable as in all of these species frontal carinae are strongly developed whereas in trogor they are absent, compare Figs 36 and 37. Besides this the antennal scapes in trogor are relatively long, with SI 100 or more, whereas the scapes are shorter in africanus , fossulatus and orbiceps with SI range 82 - 90. P. africanus and fossulatus also differ from trogor by having broad foveolate punctures on the dorsum of the head. P. orbiceps lacks the strong pronotal spines seen in trogor, having instead a pair of low broad rounded tubercles.