Ocymyrmex foreli Arnold, 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 : 269

Ocymyrmex foreli Arnold stat. n.

Ocymyrmex weitzaeckeri [sic] var. foreli Arnold , 1916: 197. Syntype workers, Zimbabwe: Redbank, 7. iv. l 912 (G. Arnold) (BMNH; NM, Bulaway) [examined].

Worker. TL 7.3 - 8.0, HL 1.76 - 1.86, HW 1.64 - 1.76, CI 92 - 95, SL 1.56 - 1.72, SI 92 - 98, PW 1.08 - 1.14, AL 2.28 - 2.44 (14 measured).

Anterior clypeal margin with a semicircular impression but this impression frequently shallower and broader than is usual in the genus; flanked by a pair of low broad tubercles or blunt small teeth formed by a thickening of the clypeal apron. Maximum diameter of eye 0.34 - 0.36, about 0.20 - 0.22 x HW. Promesonotum in profile evenly shallowly rounded and convex. Propodeal dorsum more or less flat to slightly convex, rounding broadly and evenly into the declivity. Metapleural lobes small and rounded. Petiole node in profile large, almost or quite as massively developed as in sobek , Fig. 20. In dorsal view the petiole node appearing swollen, as broad as or broader than long; postpetiole dorsally as broad as long, discounting the anterior articulatory section. Base of first gastral tergite constricted and forming a neck behind the postpetiole. Dorsum of head finely and densely longitudinally regularly costulate-rugulose, the components sharply defined and parallel. On the central part of the dorsum the sculpture is longitudinal, running straight back to the occiput or at most diverging slightly on each side of the occipital impression. More laterally on the dorsum the rugulae are divergent and arch outwards behind the eye. Ground-sculpture of head finely punctulate or granular. Pronotal dorsum usually with arched-transverse costulate sculpture followed by a patch of longitudinal sculpture which runs back between the mesothoracic spiracles. However, in some workers the sculpture here is oblique and in a few is more or less transverse. Remainder of dorsal alitrunk and also propodeal declivity transversely costulate or rugose. Petiole node coarsely sculptured everywhere, with strong, sharply defined rugae which encircle the node, running continuously across the dorsal and ventral surfaces and down the sides. Peduncle of petiole also with transverse rugulae both dorsally and ventrally, but these are weaker or effaced on the sides. All dorsal surfaces of head and alitrunk with numerous hairs; first gastral tergite also with hairs but these are shorter and much sparser than those on the alitrunk. Colour usually uniform orange-red to red throughout, but sometimes the gaster slightly lighter or darker than the alitrunk.

This species, known at present only from Zimbabwe, is closest related to sobek with which it shares the character of possessing a massively developed petiole node which is coarsely sculptured. The two are separable on colour pattern as in sobek the alitrunk is dark reddish brown to almost black, the gaster yellow and contrasting strongly with the alitrunk. The head is dull red, intermediate in colour between alitrunk and gaster. Beside this, the sculpture on the petiole is more sharply defined and regular in foreli than in sobek .

Material examined Zimbabwe: Bembesi Riv. (G. Arnold).