Strumigenys sahura

Identification
A member of the Strumigenys dagon-group.

Bolton (1983) - Along with Strumigenys dagon, Strumigenys sahura forms a close species-pair known only from Rwanda and characterized by the form of the mandibles and clypeus, though the modification of the latter is much more extreme in dagon than in sahura. The two species are separated as follows in the worker.

Distribution based on Regional Taxon Lists
Afrotropical Region: Rwanda.

Nomenclature

 *  sahura. Glamyromyrmex sahurus Bolton, 1983: 326, figs. 26, 33 (w.) RWANDA. Combination in Pyramica: Bolton, 1999: 1672; in Strumigenys: Baroni Urbani & De Andrade, 2007: 127. See also: Bolton, 2000: 298.

Worker
Holotype. TL 2.3, HL 0.56, HW 0.42, CI 75, ML 0.09, MI 16, SL 0.25, SI 57, PW 0.28, AL 0.58.

Mandibles in full-face view with the basal lamella mostly concealed by the clypeus at full closure but its margin continued as an oblique edge leading to the first tooth, which is thus some distance from the clypeal margin. Basalmost tooth small, reduced to a denticle. Distal to this is a row of 5 large teeth which are slightly recurved, and apically two denticles which share a common base are present. In profile the upper and lower mandibular margins are strongly divergent from base to apex, the dorsal margin curving upwards until it is above the level of the anterior clypeal margin and the apical (masticatory) margin forming a shallowly convex arch which is approximately at a right-angle to the long axis of the head. Anterior clypeal margin shallowly concave in full-face view, the lateral free clypeal margins expanded into a broad but shallow lobe on each side. Upper scrobe margins divergent posteriorly, straight to very shallowly concave. Posteriorly the upper scrobe margins merge with the weakly convex lateral occipital lobes which round posteriorly into the broadly shallowly concave occipital border. In profile the lateral free margins of the clypeal lobes not grossly thickened, narrower than the maximum width of the scape. Eyes present, small, situated on the ventral margin of the deep scrobe. Scapes of moderate length (SI 57-60), narrowly clavate and lacking projecting hairs on the leading edges. Dorsum of head with a pair of erect fine hairs situated close to the midline and close to the occipital margin. Head otherwise devoid of elongate hairs; lacking flagellate hairs but fairly densely clothed with curved to hooked anteriorly directed short simple hairs. Clypeus with minute appressed pubescence only. Clypeus shiny with a superficial punctulate patterning; dorsum of head behind clypeus finely but very densely and conspicuously reticulate-punctate and dull. Anterior pronotal border weakly marginate, the sides not marginate and rounded anteriorly but separated from the dorsum by a weak blunt angle posteriorly. Mesonotum not, and propodeum only weakly bluntly marginate laterally. Mesonotum separated from propodeum on dorsum by an extremely feeble ridge or crest. In profile the mesonotum slightly raised but not separated from the propodeum by a groove. Propodeal teeth vestigial to absent, not or only weakly differentiated from the infradental lamellae as minute points. Sides of alitrunk glassy smooth, without sculpture except on the extreme periphery. Pronotal dorsum unsculptured and shining; mesonotum with a smooth median longitudinal strip but punctate on each side of it; propodeum smooth anteriorly but punctate at the top of the declivity. Pronotum and mesonotum each with a single pair of long fine subflagellate hairs, otherwise only short simple appressed hairs which are directed towards the midline are present. Spongiform appendages of pedicel segments massively developed in profile. Petiole node in dorsal view unscufptured, broader than long, equipped with a strongly prominent spongiform process on each side and the two linked by a narrow lamella which runs across the posterodorsal margin of the node. Postpetiolar disc with a smooth broad median longitudinal strip but with faint shagreening on each side, the postpetiole surrounded by spongiform or lamellate material. The shallowly convex anterior margin of the post petiole is bordered by a narrow lamella which is confluent with the lateral spongiform tissue on each side. The latter is thickest posterolaterally but narrows down to a vestigial strip posteromedially where the posterior postpetiolar margin is most strongly convex. Base of first gastral tergite with a spongiform transverse trip which narrows medially behind the posteriormost point of the postpetiole. First gastral tergite with conspicuous dense basigastral costulae grouped on each side of a median smooth area. Dorsal surfaces of petiole, postpetiole and first gastral tergite with scattered erect fine hairs and with scattered short simple appressed hairs. Colour brown.

Paratypes. TL 2.1-2.3, HL 0.52-0.56, HW 0.40-0.42, CI 75-78, ML 0.09, MI 16-17, SL 0.24-0.25, SI 57-60, PW 0.26-0.28, AL 0.54-0.58 (3 measured).

As holotype but the mesonotal sculpture may consist of punctures everywhere, obliterating the median clear area seen in the holotype.

Type Material
Holotype worker, Rwanda: Rangiro, ix.1976 (P. Werner).

Paratypes. 3 workers with same data as holotype (MHNG; ; ).