Strumigenys bitheria

Identification
Bolton (1983, 2000) - A member of the nimbrata complex in the Strumigenys arnoldi-group. Closely related to Strumigenys nimbrata and sharing the striking reduction of the second and third funicular segments seen in that species, bitheria is distinguished by its broad lamellate upper scrobe margins, longer distal preapical teeth, stronger pronotal sculpture, longer narrower propodeal teeth, and by possessing a petiole node which is as long as broad in dorsal view.

Distribution based on Regional Taxon Lists
Afrotropical Region: Cameroun.

Nomenclature

 *  bitheria. Strumigenys bitheria Bolton, 1983: 367 (w.) CAMEROUN. See also: Bolton, 2000: 591.

Worker
Holotype. TL 1.9, HL 0.47, HW 0.37, CI 79, ML 0.20, MI 43, SL 0.28, SI 76, PW 0.22, AL 0.47.

Outer margins of mandibles very feebly convex in full-face view, broadest at about the level of the proximal preapical tooth and weakly tapering towards the base. Apical fork of 2 spiniform teeth, without intercalary teeth or denticles. Each mandible with 2 preapical teeth, the proximal of which is the largest and is situated Just distal of the midlength of the blade. The distance separating the bases of the pre apical teeth is less than the length of the distal preapical tooth. Anterior two-thirds of upper scrobe margins with a very conspicuous broad bordering translucent lamella or flange which is distinctly broader than the maximum diameter of the eye and approaches the maximum width of the scape. Eyes very small, with only 3-4 ommatidia, the maximum diameter of the eye distinctly less than the maximum width of the scape. Preocular notch absent, the ventral surface of the head without a transverse preocular groove or impression on each side. Antennal scapes narrow, slightly curved at the base and broadest at about the midlength, not distinctly flattened nor with the leading edges convex. Hairs fringing the leading edges of the scapes very slender, much smaller than those fringing the upper scrobe margins. Funicular segments 2 and 3 very reduced, vestigial, their combined length less than half that of the fourth (penultimate) funicular segment. Dorsum of head from posterior margin of clypeus to about the midlength densely clothed with broad conspicuous scale-like hairs. Behind this level mediodorsally are only much smaller sparse hairs but towards the sides of the occipital lobes are hairs similar in construction but smaller than those on the anterior half. Upper scrobe margins fringed with large anteriorly curved spoon-shaped hairs. Dorsum of head with 6 standing hairs arranged in a transverse row of 4 close to the occipital margin and a more anteriorly situated pair. Cephalic dorsum reticulate-punctate. Pronotal humeri each with a single fine flagellate hair. Mesonotum with a single pair of stout standing hairs. Ground-pilosity of dorsal alitrunk of small curved hairs. Posterior portion of mesonotum depressed behind the level of the standing hairs. Propodeal teeth triangular, elongate and narrow, longer than their basal width and subtended by narrow infradental lamellae. Sides of pronotum punctate, remainder of sides of alitrunk mostly smooth, with some punctate patches above and below a large smooth central area. Dorsal alitrunk reticulate-punctate, the pronotum also with some fine longitudinal rugulae. Petiole node as long as broad in dorsal view, the surface punctate. Postpetiole smooth. Spongiform appendages of pedicel segments poorly developed, the petiole with a narrow ventral strip and the node with a lateral lobe which is scarcely broader than the posterior collar. Ventral spongiform lobe of postpetiole about equal in size to the exposed area of the propodeal disc in profile. Basigastral costulae very short but stout, arising across the width of the tergite rather than on each side of a central clear area. Petiole, postpetiole and gaster with stout standing hairs which are swollen or thickened apically, colour light brown.

Type Material
Holotype worker, Cameroun: Nkoemvon, 2.iii.1980 (D. Jackson).