Polyrhachis gamaii

Nothing is known of the biology of this species, but a lone female without wings was found in South Africa in March (Bolton 1973)

Identification
Polyrhachis gamaii species-group

Distribution based on Regional Taxon Lists
Afrotropical Region: South Africa.

Nomenclature

 *  gamaii. Polyrhachis (Myrma) gamaii Santschi, 1917b: 295 (q.) SOUTH AFRICA. Arnold, 1947: 136 (w.). See also: Bolton, 1973b: 351.

Worker
Bolton (1973) - TL 7.7-8.5, HL 1.81-1.97, HW 1.70-2.08, CI 94-105, SL 1.81-2.08, SI 100-106, PW 1.18-1.48, MTL 2.37-2.59. (6 measured.)

Head truncated in front so that the clypeus is almost vertical, its anterior margin entire. Sides of head convex, the convex eyes situated well up from the ventrolateral margin, not breaking the outline of the sides of the head in full-face view. Pronotum and mesonotum not marginate, the dorsal surfaces rounding into the sides; propodeum marginate laterally. Humeral angles of the pronotum without spines but projecting as bluntly rounded tubercles. Propodeum with a pair of thick, tuberculiform teeth, directed upwards and weakly outwards. Promesonotal suture distinct; the mesoscutellum present on the dorsum, separated from the scutum in front and the propodeum behind by a pair of weakly raised, transverse carinae, best seen in profile. Petiole armed with a dorsal pair of long straight spines whose apices curve slightly inwards in front view, and with a laterally placed pair of acute teeth. The subpetiolar process is developed anteriorly into a dentiform lobe.

Erect hairs present only on the mandibles, clypeus and the apex of the gaster. A fine, sparse pubescence is present on the antennal scapes, the legs, and the first gastral segment in some individuals.

Sculpturation of head varying above the eyes from finely reticulate-punctate to superficially reticulate. The alitrunk dorsally finely reticulate to reticulate-punctate; the sides and the petiole more coarsely so. Declivity of propodeum and gaster very faintly and finely, superficially reticulate. Colouration a variable mixture of black, black-brown, red, and red-brown. Head black with red-brown mandibles, the antennal scapes red-brown or black. Alitrunk varying from red-brown with large infuscated areas to mostly black with weak red-brown or black-brown patches. The sides of the alitrunk usually red-brown but variously infuscated. Petiole and gaster varying from red-brown to black-brown; legs usually red-brown. In general the larger individuals tend to have more black and less red on the alitrunk than do the smaller forms.

Queen
Bolton (1973) - In general body form and sculpturation the differences between the female and the workers are only as expected between the two castes, but the female is distinctly more pilose and has the petiolar spines disproportionally spaced in comparison to the worker. Marked similarities include the head shape, development of pronotal tubercles and propodeal teeth, form of petiole, and the presence of a dentiform subpetiolar process.

Type Material
Bolton (1973) - Holotype queen, SOUTH AFRICA : Natal, Durban (H. B. Marley) (probably in NM, Basle).

References based on Global Ant Biodiversity Informatics

 * Arnold G. 1924. A monograph of the Formicidae of South Africa. Part VI. Camponotinae. Annals of the South African Museum 14: 675-766.
 * Robson Simon Database Polyrhachis -05 Sept 2014
 * Santschi F. 1917. Fourmis nouvelles de la Colonie du Cap, du Natal et de Rhodesia. Annales de la Société Entomologique de France. 85: 279-296.
 * Wheeler W. M. 1922. Ants of the American Museum Congo expedition. A contribution to the myrmecology of Africa. VIII. A synonymic list of the ants of the Ethiopian region. Bulletin of the American Museum of Natural History 45: 711-1004