Polyrhachis aerope

The holotype was found in the stomach of a frog.

Identification
A member of the Polyrhachis militaris species-group. Bolton (1973) - As Wheeler (1922a:266) points out, this species is very closely related to Polyrhachis concava. The two species may be separated by the larger size of concava (TL 6.8 or more), the different shape of the sides of the head, and the notably greater SI of 172 or more. Besides these characters, Wheeler makes no mention of any modification of the ventral margin of the eye, a feature typical of concava; but if the eye of aerope is modified as in concava then the synonymy of the two species will have to be considered.

Distribution based on Regional Taxon Lists
Afrotropical Region: Cameroun, Congo, Democratic Republic of Congo.

Nomenclature

 *  aerope. Polyrhachis aerope Wheeler, W.M. 1922a: 265, fig. 72 (w.) DEMOCRATIC REPUBLIC OF CONGO. See also: Bolton, 1973b: 296.

Worker
Bolton (1973) - TL “somewhat less than 6 mm”. CI approx. 74, SI approx. 147 (approximated from Wheeler, 1922a, fig. 72c).

Anterior clypeal margin arcuate, entire. Eyes convex, prominent. The sides of the head in front of the eyes shallowly convex. Behind the eyes the sides round into the very convex occipital margin. Alitrunk marginate throughout its length, the margination interrupted at the sutures. Dorsal surface of alitrunk concave, with strong, upturned margins. Pronotum armed with a pair of long, acute spines; propodeum with a pair of small, slightly recurved teeth. Promesonotal suture distinct; metanotal groove developed, impressed. In dorsal view the lateral margins of the pro- and mesonota converging posteriorly, almost parallel on the propodeum. Petiole with a pair of long dorsal spines and a laterally placed pair of teeth.

Erect hairs absent from dorsal surfaces of head and body; pubescence short and sparse, visible only on sides of alitrunk, clypeus and appendages.

Gaster very minutely and superficially punctate; head, thorax and petiole finely coriaceous or shagreened. Colour black, the palpi and antennal insertions reddish.

Type Material
Bolton (1973) - Holotype worker, CONGO (KINSHASA): Niangara (Lang and Chapin) (depository unknown).

I have not been able to see the unique worker of this species, but the original description and figures are good enough to delimit the species.

References based on Global Ant Biodiversity Informatics

 * Wheeler W. M. 1922. Ants of the American Museum Congo expedition. A contribution to the myrmecology of Africa. II. The ants collected by the American Museum Congo Expedition. Bulletin of the American Museum of Natural History 45: 39-269.