Polyrhachis weissi

Identification
Rigato (2016) - Polyrhachis weissi looks easily identifiable within the revoili-group for this unique combination of features: 1) clypeus with an uniformly rounded anterior margin; 2) head in full face view distinctly trapezoidal with a strongly transverse, weakly convex posterior border; 3) eyes moderately convex and placed close to posterior corners; 4) mesosoma fully immarginate and stout (in dorsal view pronotum and mesonotum strongly transverse, propodeal dorsum trapezoidal, much wider in front than behind and distinctly shorter than its maximum width); 5) propodeal dorsum bearing a pair of small, sharp upturned teeth at its posterior corners; 6) petiole with two pairs of spines, the mid pair slightly curved backward and distinctly longer; 7) body mostly reticulate punctate with superimposed fine longitudinal rugulae on cephalic and mesosomal dorsa (cephalic rugulae tidier); 8) standing hairs moderately long and abundant all over the body and legs, mostly yellowish in colour.

The presence and number of standing hairs on scapes could suggest the existence of two distinct species. Some nest series have 0 to few standing hairs on scapes, whereas other samples have more than 30, without any seemingly intermediate condition. Because of lack of further reliable distinctive characters, I prefer to consider these alternative conditions as a matter of intraspecific variability.

Distribution based on Regional Taxon Lists
Afrotropical Region: Cameroun, Central African Republic, Congo, Democratic Republic of Congo, Ghana, Guinea, South Africa, Zambia.

Nomenclature

 *  weissi. Polyrhachis weissi Santschi, 1910c: 395, fig. 18 (w.) CONGO. Combination in P. (Pseudocyrtomyrma): Emery, 1925b: 207; in P. (Myrma): Wheeler, W.M. 1922a: 1004; Bolton, 1973b: 342. Subspecies of revoili: Forel, 1916: 453; Emery, 1925b: 207; Santschi, 1939c: 12. Status as species: Wheeler, W.M. 1922a: 1004; Bolton, 1973b: 342. Senior synonym of balli, conduensis, crassa and material of the unavailable name phaenogaster referred here: Bolton, 1973b: 342.
 * conduensis. Polyrhachis (Myrma) revoili var. conduensis Forel, 1915c: 351 (w.) DEMOCRATIC REPUBLIC OF CONGO. Combination in P. (Pseudocyrtomyrma): Emery, 1925b: 207. Junior synonym of weissi: Bolton, 1973b: 342.
 * crassa. Polyrhachis (Pseudocyrtomyrma) revoili subsp. crassa Emery, 1921e: 23, fig. 2 (w.q.) CAMEROUN. Junior synonym of weissi: Bolton, 1973b: 342.
 * balli. Polyrhachis (Pseudocyrtomyrma) revoili st. balli Santschi, 1939c: 10 (w.) DEMOCRATIC REPUBLIC OF CONGO. Junior synonym of weissi: Bolton, 1973b: 342.
 * natalensis. Polyrhachis natalensis Santschi, 1914e: 41 (w.) SOUTH AFRICA. Combination in P. (Myrma): Wheeler, W.M. 1922a: 999; in P. (Pseudocyrtomyrma): Emery, 1925b: 207. Status as species: Wheeler, W.M. 1922a: 999. Subspecies of revoili: Emery, 1925b: 207; Santschi, 1939c: 12. Junior synonym of revoili: Forel, 1916: 453; Arnold, 1924: 754; Bolton, 1973b: 338; of weissi: Rigato, 2016: 44.
 * donisthorpei. Polyrhachis (Myrma) revoili var. donisthorpei Forel, 1916: 453 (w.) ZAMBIA. [Also described as new by Forel, 1917: 252.] Combination in P. (Pseudocyrtomyrma): Emery, 1925b: 207. Junior synonym of revoili: Bolton, 1973b: 338; of weissi: Rigato, 2016: 44.

Type Material
Rigato (2016) - Holotype worker, CONGO: Brazzaville (A. Weiss).