Strumigenys rufobrunea

Known from forest litter-samples.

Identification
Bolton (2000) - A member of the rufobrunea complex in the Strumigenys arnoldi-group. Of the three species in the complex Strumigenys petiolata is easily distinguished as it lacks a flagellate hair at the pronotal humerus; this specialised hair is conspicuous in both Strumigenys faurei and rufobrunea. The last two form a close species-pair and some samples may be difficult to differentiate except zoogeographically, as faurei occupies Tanzania and South Africa whilst rufobrunea is restricted to West African states. However, in the majority of cases faurei has the postpetiole disc finely sculptured when clean and has the preocular groove on the ventral surface of the head quite short and with poorly defined anterior and posterior margins. In rufobrunea the postpetiole disc, when clean, is always glassy smooth and the preocular groove is longer and has sharply defined anterior and posterior margins.

Bolton (1983) - West African rufobrunea and the South African Strumigenys faurei, known at present only from Natal, both of which possess humeral flagellate hairs. S. faurei differs by having the postpetiole densely costulate, the subpetiolar process very reduced, the petiole node twice broader than long dorsally, and the ventral preocular impression broader and less sharply defined.

Distribution based on Regional Taxon Lists
Afrotropical Region: Cameroun, Ghana, Guinea, Ivory Coast, Nigeria, Togo.

Nomenclature

 *  rufobrunea. Strumigenys rufobrunea Santschi, 1914d: 373 (w.q.) GUINEA. See also: Brown, 1954k: 17; Bolton, 1983: 389; Bolton, 2000: 605.

Worker
Bolton (1983) - TL 1.8-2.0, HL 0.48-0.53, HW 0.36-0.40, CI 73-76, ML 0.22-0.25, MI 45-48, SL 0.25-0.29, SI 69-74, PW 0.23-0.25, AL 0.42-0.49 (12 measured).

Mandibles in full-face view with the outer margins shallowly convex, the blades slightly bowed outwards. Apex of each mandible with 2 spiniform fork teeth, without intercalary teeth or denticles. Preapical armament of each mandible of 2 teeth, the proximal spiniform and longer than the distal; in general the distal preapical tooth of the left mandible slightly shorter than that of the right. Distance separating the bases of the preapical teeth on the left mandible at least as great as the length of the distal preapical tooth and usually greater. Upper scrobe margins shallowly sinuate rather than straight, bordered by a narrow rim or flange throughout their length. Eyes of moderate size, not concealed by the upper scrobe margins and visible in full-face view, their maximum diameter greater than the maximum width of the scape. Preocular notch present and strongly developed, the anterior portion of the eye detached from the side of the head. Preocular notch extended onto the ventral surface of the head as a transverse impression in front of the eye. Antennal scapes very shallowly bent in the basal third, slightly expanded in the median third and broadest at about the midlength. Leading edges of scapes with a row of apically curved hairs which are spatulate to narrowly spoon-shaped and conspicuously smaller than the hairs bordering the upper scrobe margins. Ground-pilosity of cephalic dorsum of inconspicuous small spatulate hairs which are closely applied to the surface, the upper scrobe margins with a very obvious row of larger broadly spoon-shaped hairs which are curved anteriorly. Dorsum of head with 6 standing hairs arranged in a transverse row of 4 close to the occipital margin and a more anteriorly stituated pair. Dorsum of head reticulate-punctate. Pronotal humeri each with a single fine flagellate hair. Mesonotum with a single pair of standing hairs, the dorsal alitrunk otherwise with only sparse appressed minute pilosity similar to that which forms the cephalic ground-pilosity. Posterior portion of mesonotum depressed behind the level of the standing hairs. Metanotal groove present as a line across the dorsum which is not or only very feebly impressed. Propodeal teeth triangular and subtended by a moderately developed infradental lamella which is confluent with the tooth for about half its length. Sides of pronotum showing vestigial costulate or striolate sculpture, or traces of punctures which are almost effaced. Pleurae smooth except for some peripheral punctulation. Pronotal dorsum finely longitudinally costulate or rugulose, sometimes with feeble punctures between the costulae. Remainder of dorsal alitrunk densely reticulate-punctate. Dorsum of petiole node densely and quite strongly reticulate-punctate, the node itself slightly broader than long but not a narrow transverse rectangle. Postpetiole smooth or rarely with vestiges of longitudinal striolate sculpture laterally. Spongiform appendages of pedicel segments moderately developed, the ventral petiolar strip spongiform but usually confined to the posterior two-thirds of the length. Ventral spongiform lobe of postpetiole fractionally larger than the lateral lobe. Basigastral costulae sharply defined. Petiole, postpetiole and gaster dorsally with stout standing hairs which are swollen to feebly clavate apically. Colour usually with head and alitrunk medium brown, the gaster darker brown, but uniformly dark individuals also occur.

Type Material
Bolton (1983) - Lectotype female (designated by Brown, 1954: 17), and paralectotype worker, GUINEA: Conakry (F. Silvestri) [examined].