Rhoptromyrmex opacus Emery

Type location Cameroun (Emery, in Forel, 1909b: 59, footnote, worker) collector L. Conradt; junior synonyms esta (Forel, 1909b: 59, all forms) from Zaïre, laeviceps (Santschi, 1916b: 504, worker) from Zaïre collected at Boma, by Bondroit; and monodi (Bernard, 1952: 251, illustrated, worker) from Guinea, one worker from Mt. Nimba, Ziéla, station F 32, savannah, collector Lamotte; all forms described (see Bolton, 1995) .

WORKER - TL 2.5 mm; mandibles large, subopaque with 7-8 teeth, striato-punctate; head large and cordiform, as with transversinodis and globulinodis but shorter and wider, sides very convex; more pronounced forwards, clypeus subcarinate and forming a rounded lobe. Scape reaching posterior sixth of head; funiculus segments 2-8 narrower than long. Metanotal groove distinct (missing on Mayr species). Petiole pedicel short (longer in Mayr species); node rounded cuboid, slightly wider than long; postpetiole node bigger, but no higher. With twelve-segmented antennae; the head and alitrunk usually with dense, opaque reticulate-punctate sculpture; propodeum unarmed; head and gaster always with standing hairs, but not always so on the alitrunk. Colour darkish yellow, head and thorax reddish. (Emery, in Forel, 1909b: 59, footnote, worker; Bolton, 1976, not illustrated; Bolton, 1986, fully illustrated).

Forel (1909b) described esta as having a smaller head, somewhat longer than wide, sides less convex and without a medina carina on the clypeus; otherwise similar although shoulders of pronotum more rounded. He also described the queen and male. All the specimens came from the stomach of a Pangolin in Bas Congo, collected by Solon. The latter was referred to by Santschi (1916b) who described laeviceps as differing in having less obvious sculpturation and being shinier.

Wheeler (1922) described its collection in Zaïre by Bequaert, as nesting in sandy soil in the savannah.

Bernard (1952) described his new subspecies monodi as follows - TL 2.2 mm, length, striation, form of the head and of petiole nodes, similar to the type opacus from Congo. Occiput and thorax brown-black, face red-orange, clypeus yellow (orange in type). Propodeum clearly angular in profle, with two dentiform ridges on the posterior face, angled also on the sides (entirely rounded on the sides in the type).

Bolton's modern description (1986a) is at .

Also known from Uganda (Bolton, 1976, 1986).

The photomontage is collated from http://www.antweb.org/specimen.do?name=casent0005920
Collection details - Congo: ; km. 94 on Kavumu Walikale route; 00°00'00"N 000°00'00"E, 900m. Collection Information: Collection codes: ANTC1254. Date: 17 Sep 1957. Collected by: E. S. Ross & R. E. Leech .