Hypoponera lassa

A small species collected from leaf litter in Ivory Coast and Ghana.

Identification
Bolton and Fisher (2011) - Hypoponera lassa is closely related to Hypoponera defessa and the widespread Hypoponera fatiga. All three are small (HW 0.36–0.46), eyeless, brownish-yellow to brown species in which the metanotal groove is absent, the cinctus of the second gastral tergite has cross-ribs and the disc of the second gastral tergite is superficially reticulate-punctate to microreticulate. H. defessa is distinguished from both fatiga and lassa by its lack of a raised median longitudinal clypeal ridge, which is conspicuous in the last two named. In addition, the petiole node in defessa is columnar in profile and relatively stout (LPeI 46–53), is D-shaped in dorsal view and is longer relative to its width (DPeI 134–150). In fatiga and lassa the correponding indices combined are LPeI 37– 44 and DPeI 155–180. In the order lassa – defessa – fatiga the three species show a morphoclinal reduction in the density and intensity of the punctate sculpture of the lateroventral surfaces of the head. In lassa the sculpture is nearly reticulate-punctate, with the individual punctures sharply defined and closely packed, the distances between the punctures generally less than the puncture diameters; in defessa the punctures are still sharply defined but more widely spaced, the distances between the punctures equal to or greater than the puncture diameters; in fatiga the punctures are widely spaced, minute, feeble and superficial. The ratio SL/HL shows a combined range of 0.65–0.71 in defessa and lassa, but tends to average somewhat lower in fatiga, 0.60–0.67.

Distribution
Known from Ivory Coast and Ghana

This taxon was described from Ghana.

Nomenclature

 *  lassa. Hypoponera lassa Bolton & Fisher, 2011: 66, figs. 64-66 (w.q.) GHANA.

Worker
Measurements: HL 0.51–0.56 (0.54), HW 0.40–0.44 (0.44), HS 0.455–0.495 (0.490), SL 0.34–0.38 (0.37), PrW 0.31–0.35 (0.34), WL 0.66–0.74 (0.72), HFL 0.34–0.40 (0.38), PeNL 0.13–0.16 (0.14), PeH 0.33–0.38 (0.37), PeNW 0.22–0.25 (0.24), PeS 0.227–0.260 (0.250) (10 measured). Indices: CI 77–81 (81), SI 84–90 (84), PeNI 70–78 (71), LPeI 37–43 (38), DPeI 155–171 (171).

Eyes absent. Median portion of clypeus with a raised median longitudinal ridge or crest. Apex of scape, when laid straight back from its insertion, distinctly fails to reach the midpoint of the posterior margin in full-face view; SL/HL 0.65–0.71. Reticulate-punctate sculpture on cephalic dorsum fine and dense, the punctures crowded, small and sharply defined. Lateroventral areas of head distinctly punctate, the sculpture almost reticulate-punctate but not as closely packed as on the dorsum. Punctate sculpture on disc of pronotum more diffuse than on lateroventral surface of head. Metanotal groove absent from dorsum of mesosoma. Sides of propodeal declivity marginate but not carinate. Petiole node in dorsal view transverse, the anterior surface more convex than the posterior but not thickly D-shaped. Petiole node in profile tall and slender, with the sides weakly convergent from just above tubercle to apex; anterior face often extremely shallowly concave, dorsum shallowly convex. Posterior surface of petiole node without radiating cuticular ribs above the peduncle. Subpetiolar process with a ventral angle that may be sharp or blunt and a short ascending posterior surface behind the angle. Base of cinctus of second gastral tergite with short, inconspicuous cross-ribs. Disc of second gastral tergite microreticulate to superficially reticulate-punctate; without sharply incised, widely separated punctures. Maximum width of first gastral tergite in dorsal view is less than the width of the second tergite at its midlength. Midline length of second gastral posttergite, from posterior margin of cinctus to apex, is slightly less than the maximum width of the segment. Suberect to erect setae on dorsum of first gastral tergite sparse and short, stubbly. Full adult colour light brown, the appendages lighter.

Type Material
Holotype worker (top specimen of two on pin), Ghana: Sagymasi, iii.1992 (R. Belshaw).

Paratypes. 2 workers and 1 dealate queen with same data as holotype, one of the workers mounted below the holotype (BMNH).