Strumigenys sulumana

Identification
Bolton (1983) - A very distinctive small species of Serrastruma (= Strumigenys) immediately separated from all its congeners by its combination of narrow head with relatively long mandibles and extremely long scapes, reduced upper scrobe margins which lack flagellate hairs, inconspicuous cephalic ground pilosity, presence of humeral flagellate hairs but lack of specialized large hairs on the mesonotum, and vestigial spongiform tissue on the pedicel segments.

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

Nomenclature

 *  sulumana. Serrastruma sulumana Bolton, 1983: 352 (w.) CAMEROUN. Combination in Pyramica: Bolton, 1999: 1673; in Strumigenys: Baroni Urbani & De Andrade, 2007: 128. See also: Bolton, 2000: 319.

Worker
Holotype. TL 2.0, HL 0.50, HW 0.33, CI 66, ML 0.22, MI 44, SL 0.40, SI 121, PW 0.23, AL 0.58.

Small narrow-headed species with relatively long mandibles and very long scapes. Mandibles slender, serially finely denticulate, the apical tooth subspiniform and the denticles becoming gradually slightly larger towards the base. Rounded angle separating masticatory and basal margins of mandible surmounted by a thin translucent crest which follows the curve and represents the remains of the basal lamella. Anterior clypeal margin translucent and convex, overhung by the false clypeal margin which is equipped with anteriorly projecting hairs. Antennal scrobes vestigial, the dorsum rounding into the sides except in front of the level of the eye where a feebly angular upper scrobe margin remains. The eyes freely visible in full-face view on the ventrolateral margins of the head because of the disappearance of the upper scrobe margins which partially or wholly obscure them in most other members of the genus. Occipital corners evenly rounded, the occipital margin shallowly concave. Antennal scapes very long and slender, subcylindrical, slightly increasing in thickness from base to apex, the leading edges only with fine curved hairs, without bizarre projecting pilosity. Ground-pilosity of head of inconspicuous curved narrowly spatulate hairs. A transverse row of 4 stouter more erect hairs present paralleling the occipital margin but the head without flagellate hairs. Dorsum of head finely and densely reticulate-punctate. Pronotum not marginate laterally, the humeri broadly rounded and each with a long fine flagellate hair. In profile the posterior half of the mesonotum descending steeply to the broadly impressed metanotal groove. Propodeal dorsum elevated behind the level of the metanotal groove then sloping shallowly backwards. Propodeal teeth elevated, long and narrowly triangular, without an infradental lamella. Sides and dorsum of alitrunk evenly and densely reticulate-punctulate everywhere. Dorsal alitrunk with inconspicuous curved narrowly spatulate pilosity, the mesonotum without standing specialized hairs such as are usually seen in Serrastruma species. Petiole and postpetiole reticulate-punctate everywhere, the gaster smooth and with vestigial basal costulae. Spongiform appendages of pedicel segments very reduced. In profile the subpetiolar appendage reduced to a narrow translucent strip and the subpostpetiolar lobe represented only by a thin laminar fringe around the curve of the sternite. In dorsal view the petiole and postpetiole each with minute vestiges of their respective transverse posterior spongiform strips, the best developed section being at the posterolateral angles of the postpetiole. Petiole, postpetiole and gaster dorsally with a number of erect to suberect quite stout hairs which are thickened apically. Colour pale yellow.

Paratype. TL not measurable as pedicel segments and gaster missing, HL 0.56, HW 0.36, CI 64, ML 0.25, MI 45, SL 0.46, SI 127, PW 0.24, AL 0.62. As holotype.

Type Material
Holotype worker, Cameroun: nrYaounde, sample SK (G. Terron). Paratype. 1 worker with same data as holotype.