Strumigenys dextra

Known from more than twenty collections, all from wet forest litter samples.

Identification
Bolton (1983, 2000) - A member of the dextra complex in the Strumigenys arnoldi-group. In the dextra-complex three other species beside dextra have lost the distal preapical tooth of the left mandible, Strumigenys irrorata, Strumigenys katapelta and Strumigenys paranax. The first of these is distinguished from dextra and the rest by also lacking the distal preapical tooth on the right mandible so that both blades have only a single preapical tooth. S. katapelta is the only species of the four which possesses intercalary teeth between the spiniform teeth of the apical forks, and paranax is easily separated from dextra by its possession of a straight stout projecting hair at the humeri where dextra has a long fine flagellate hair present.

Elsewhere in the genus Strumigenys bernardi, Strumigenys sarissa and Strumigenys londianensis also have only a single preapical tooth on the left mandible, but in all of these there is a large and very distinct preocular notch present.

Distribution based on Regional Taxon Lists
Afrotropical Region: Angola, Cameroun, Central African Republic, Democratic Republic of Congo, Equatorial Guinea, Gabon, Kenya, Uganda.

Nomenclature

 *  dextra. Strumigenys dextra Brown, 1954k: 27 (w.) UGANDA. See also: Bolton, 1983: 368; Bolton, 2000: 592.

Worker
Bolton (1983) - TL 1.6-1.8, HL 0.41-0.47, HW 0.31-0.34, CI 71-77, ML 0.16-0.19, MI 38-42, SL 0.22-0.25, SI 68-75, PW 0.21-0.24, AL 0.40-0.48 (10 measured).

Mandibles relatively slender, shallowly and evenly curved along the outer margins. Apical fork of each mandible of two teeth, without intercalary teeth or denticles. Preapical armament of left mandible of a single tooth, the right mandible with 2 preapical teeth. Upper scrobe margins concealing the eyes in full-face view. Eyes small, with only 3--5 ommatidia, the maximum diameter of the eye distinctly less than the maximum width of the scape. Pre ocular notch absent, the ventral surface of the head without a transverse preocular groove or impression on each side. Antennal scape shallowly curved basally, somewhat expanded in the median third, the leading edges with a row of apically curved narrow spoon-shaped hairs. Ground-pilosity of cephalic dorsum reduced, consisting of a few inconspicuous small spatulate haits. Upper scrobe margins with a triple row of larger narrowly 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. Pronotal humeri each with a single fine flagellate hair. Mesonotum with a single pair of standing stout hairs which are clavate apically. Ground-pilosity of dorsal alitrunk of inconspicuous narrowly spatulate hairs like those on dorsum of head. In profile the mesonotum feebly or not depressed behind the level of the standing hairs. Propodeal teeth short and subtended by moderately developed infradental lamellae. Sides of pronotum almost smooth to weakly longitudinally rugulose. Pleurae and sides of propodeum smooth except for weak peripheral punctures. Dorsal alitrunk with sparse widely separated longitudinal rugulae on pronotum, the spaces between the rugulae smooth or with vestiges of superficial sculpture. Remainder of dorsal alitrunk reticulate-punctate. Dorsum of petiole node punctate, the postpetiole smooth. Spongiform appendages of pedicel segments only moderately developed. In profile the petiole with a narrow ventral strip and small lateral appendage on the node. Ventral spongiform lobe of postpetiole equal to or Slightly smaller than the exposed area of the postpetiolar disc in profile. Basigastral costulae short but sharply defined, arising across the width of the first tergite basally, not radiating on each side of a broad central clear area. Dorsal surfaces of petiole, postpetiole and gaster with stout standing hairs which are narrowly clavate apically. Colour dull yellow.

Type Material
Bolton (1983) - Holotype and paratype workers, UGANDA: 5 miles (8 km) N. Kamapala, Kawanda Exp. Sta., 15.ii.1949, no. SS 30, soil sample under elephant grass (G. Salt) [examined].