Monomorium draxocum

Specimen records show this is species lives in mesic forests.

Identification
Bolton (1987) - A conspicuous species characterized within the group with Monomorium noxitum, Monomorium gabrielense and Monomorium strangulatum by the form of the clypeus, position of the eyes, length of the scapes, biconvexity of the head and strongly domed promesonotum. Also diagnostic of this small complex of species is the relatively long petiolar peduncel and subconical node, as illustrated in gabrielense.

Of these four species strangulatum has only 11 antennal segments, and gabrielense is small and lightly coloured. M. draxocum and noxitum are very closely related and may prove inseparable when more material had been amassed. Characters separating them in presently available material are listed under noxitum.

Distribution based on Regional Taxon Lists
Afrotropical Region: Angola, Cameroun, Gabon, Kenya, Uganda.

Nomenclature

 *  draxocum. Monomorium draxocum Bolton, 1987: 385 (w.) CAMEROUN.

Worker
Holotype. TL 1.8, HL 0.41, HW 0.34, CI 83, SL 0.36, SI 106, PW 0.22, AL 0.46.

Clypeal carinae sharply developed, widely separated and subparallel, only very feebly divergent anteriorly and reaching the anterior clypeal margin. Prominent median portion of clypeus with its anterior margin sharply defined and very feebly concave between the apices of the carinae, the anterior and lateral margins of the prominence meeting in an obtuse angle but without projecting denticles. Maximum diameter of eye 0.23 x HW and with 5 ommatidia in the longest row. In full-face view the eyes situated close to the midlength of the side of the head. Antennal scapes, when laid straight back from their insertions, slightly exceeding the occipital margin. Sides of head behind eyes shallowly convex and rounding broadly into the weakly convex occipital margin. In profile both the dorsal and ventral surfaces of the head markedly convex (shape very similar to gabrielense, Fig. 76). Promesonotal dorsal outline high and domed-convex in profile, on a very much higher level than the propodeal dorsum. Mesonotum descending steeply posteriorly to the broadly but shallowly impressed metanotal groove. Metanotal cross-ribs conspicuous dorsally, but laterally becoming confused with the strong mesopleural sculpture. Propodeal dorsum evenly convex in profile, rounding broadly into the declivity. Petiole node subconical, tapering and narrowly rounded dorsally. Anterior peduncle relatively long and subtended by a ridge-like ventral process which is expanded into a small lobe anteriorly. Postpetiole node smaller than petiole, with a steep anterior face but more broadly rounded above than the petiole node. All dorsal surfaces of head and body with stout conspicuous standing hairs, the promesonotum with 4 pairs. Scattered hair-pits present on head and body, metanotal cross-ribs conspicuous, and the mesopleuron strongly reticulate-punctate; sculpture otherwise absent. Head and alitrunk dark brown, gaster black. Legs conspicuously much lighter than alitrunk, tending to be very pale yellow or almost colourless.

Paratypes. TL 1.7-1.9, HL 0.39-0.42, HW 0.32-0.35, CI 79-83, SL 0.32-0.36, SI 100-109, PW 0.22-0.23, AL 0.44-0.46 (8 measured). As holotype but maximum diameter of eye 0.21-0.24 x HW and with 5-6 ommatidia in longest row. With 4-5 pairs of standing hairs on the promesonotum.

Type Material
Holotype worker, Cameroun: Nkoemvon, 25.xi. 1980, no. N52 (D. Jackson). Paratypes. 5 workers with same data as holotype, and 3 workers with same locality but 6.x. 1980, no. N34 (BMNH; ).