Hypoponera sinuosa

Known only from a single type, the specimen was collected in a forested ravine.

Identification
See the nomenclature section below.

Distribution
This taxon was described from Guinea.

Castes
Queens and males have not been collected.

Nomenclature

 *  sinuosa. Ponera sinuosa Bernard, 1953b: 204, fig. 3 (w.q.) GUINEA. Combination in Hypoponera: Bolton, 1995b: 216. See also: Bolton & Fisher, 2011: 100.

Only a single damaged worker specimen of this strange little species is known and no other specimen that approaches the sinuosa lectotype has been seen. In general there is some resemblance to workers of Hypoponera coeca and Hypoponera inaudax, but in those common species there is never a developed metanotal groove on the dorsal mesosoma. Bernard’s description is misleading on several counts. His fig. 3E, showing a widely sinuate propodeal declivity, is inaccurate as only its lateral margin curves in towards the metapleural gland bulla at its base. He also says that the mandible has six spaced teeth where in reality the left mandible has a total dental count of 9 and the right mandible has 8. The petiole in profile is not shaped as indicted in his fig. 3E. In reality the anterior and posterior faces are markedly convergent dorsally and the LPeI is 47; in the figure the faces are nearly parallel and the LPeI obtained from the sketch is about 39.

The position of sinuosa in the key is conjectural. In the single worker available, the base of the cinctus of the second gastral tergite cannot be seen. The tergites of gastral segments one and two are jammed very tightly together and disturbing them could cause even more damage to the unique lectotype. However, because of its overall similarlity to Hypoponera punctatissima and Hypoponera ragusai, cross-ribs are assumed to be absent. Thus two assumptions are made to place sinuosa in the key. First, that the detached and separately mounted gaster is actually associated with the head and mesosoma, and second, that because cross-ribs are absent in related species on the tergal cinctus, they will also be absent here.

Worker
Bolton and Fisher (2011) - Lectotype. Measurements: HL 0.52, HW 0.43, HS 0.475, SL 0.37, PrW 0.33, WL 0.74, HFL 0.38, PeNL 0.14, PeH 0.30, PeNW 0.22, PeS 0.220. Indices: CI 83, SI 86, PeNI 67, LPeI 47, DPeI 157.

Eyes at first glance absent, but appropriate lighting conditions and viewing angle reveal a blister-like minute ommatidium, about 0.11 from the anterolateral clypeal margin. Apex of scape, when laid straight back from its insertion, just touches the midpoint of the posterior margin in full-face view; SL/HL 0.71. Funiculus with 5 enlarging segments. Mesonotal-mesopleural suture entirely absent. Anterior margin of mesopleuron obtusely angulate, almost rounded, without a projecting angle or tooth. Metanotal groove distinct on dorsum, transverse; in profile not impressed. Sides of propodeum in dorsal view bilaterally pinched just posterior to the metanotal groove. In profile the pinched side appears as a broad, shallow depression that extends from the posterior margin of the mesopleuron about half-way to the propodeal spiracle. Propodeal declivity and side meet in a distinct angle, but no carina is present. In profile base of lateral margin of propodeal declivity curves anteriorly to metapleural gland bulla. Petiole node in profile with anterior and posterior faces markedly convergent dorsally, the dorsal surface narrowly rounded; in profile the dorsal length of the node is less than half the length just above the anterior tubercle of the petiole. In dorsal view the petiole node broader than long, with posterior face transverse and anterior face convex. Posterior surface of node smooth, without vertical cuticular ridges above the peduncle. First gastral tergite with quite dense decumbent pubescence and apparently with a few short, standing setae also present (condition of gaster is poor). Disc of second gastral tergite microreticulate. In dorsal view second gastral tergite at its midlength is broader than the maximum width of the first tergite. Full adult colour yellow.

Type Material
LECTOTYPE worker (by present designation), GUINEA: ravin 1 de la forêt du Mont Tô, 21.ii. (Lamotte) [examined].

Additional References

 * Bolton, B. & Fisher, B.L. 2011. Taxonomy of Afrotropical and West Palaearctic ants of the ponerine genus Hypoponera Santschi. Zootaxa 2843: 1-118.