Polyrhachis volkarti

Identification
Rigato (2016) - A medium sized revoili-group species with lobed clypeus, immarginate mesosoma (at most the pronotum bears a trace of lateral margination), and propodeal dorsum wider than long.

The P. volkarti gyne looks very similar to the Polyrhachis kohli gyne, except for the significant differences concerning pilosity and propodeum summarized under kohli. The workers I assigned to volkarti have pilosity and propodeal proportions highly comparable to those of the holotype gyne; yet further discoveries could demonstrate such workers to belong to a still undescribed species.

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

Nomenclature

 *  volkarti. Polyrhachis (Myrma) revoili r. volkarti Forel, 1916: 453 (q.) DEMOCRATIC REPUBLIC OF CONGO. Combination in P. (Pseudocyrtomyrma): Emery, 1925b: 207. Raised to species: Bolton, 1973b: 341.

Worker
Rigato (2016) - workers from the Republic of the Congo (n=5) HL 1.36–1.45, HW 1.11–1.16, CI 80–83, SL 1.74–1.85, SI 151–162, FW 0.40–0.41, FI 35–37, PW 1.00–1.06, WL 1.87–1.99, HTL 1.70–1.81. They look conspecific with the holotype gyne in all main features, even if sometimes an ill-defined trace of pronotal margination appears anteriorly behind the pronotal teeth.

Queen
Rigato (2016) - Holotype. HL 1.50, HW 1.15, CI 77, SL 1.95, SI 170, FW 0.41, FI 36, MnL 1.78, ScW 1.45, WL 2.52, HTL 1.97.

Clypeus bearing a slightly protruding rectangular lobe at its anterior margin. Head in full face view oval, wider behind than in front, posterior margin evenly convex without distinct posterior corners; sides in front of the eyes straight. Eyes relatively large and convex. Ocelli small. Pronotal and propodeal sides immarginate. Pronotal teeth small and robust. Propodeal dorsum distinctly wider than long, arched both longitudinally and transversely. Propodeal ridges small and far apart, between them the propodeal dorsum smoothly merges into the declivity. Petiole with a mid pair of diverging and slightly backward bent spines, whose reciprocal distance is about twice the length of each spine, and a pair of much shorter lateral teeth raising near the bases of the spines. First gastral tergite anteriorly weakly concave.

Mandibles mostly smooth and shining, weakly shagreened at their insertion. Body and appendages finely reticulate-punctate; sculpturation stronger on the opaque head and mesosoma. Cephalic dorsum, except clypeus, with a superimposed longitudinal fine rugulation.

The whole body and appendages with fairly abundant standing hairs; longest hairs occur on scutellum and cephalic dorsum. Hairs on tibiae short, at most as long as maximum tibial width; hairs on scapes at most 1.5 as long as the maximum scape diameter. Pubescence whitish, moderately long and abundant throughout the body, but never hiding the sculpturation; on the gaster the distance between two adjacent elements is about equal to their length.

Colour mostly black, tibiae dark brown, tarsi apically partially ferrugineous. Funiculi mostly ferrugineous, except the 4 basalmost joints, which are basally darkened. Mandibles apically ferrugineous.

Type Material
Rigato (2016) - Holotype gyne, DEMOCRATIC REPUBLIC of the CONGO (H. Kohl). (MHNG) [examined].