Polyrhachis viscosa F. Smith

Rigato, Fabrizio, 2016, The ant genus Polyrhachis F. Smith in sub-Saharan Africa, with descriptions of ten new species. (Hymenoptera: Formicidae), Zootaxa 4088 (1) : 42-43

Polyrhachis viscosa F. Smith

( Figures 14 a–c)

Polyrhachis viscosa F. Smith, 1858: 71 , pl. 4, fig. 41. Holotype worker, SOUTH AFRICA: Natal, Durban (BMNH) [not seen].

Polyrhachis antinorii Emery, 1877: 365 . Syntype workers, ERITREA: Sciotel and Keren, 1870 (O. Beccari) (MSNG) [examined]. [Synonymy by Dalla Torre, 1893: 271]

Polyrhachis viscosa var. spretula Santschi, 1923: 294 . Syntype workers and gyne, DEM. REP. of the CONGO: Kasai, Dumbi, 6.x.1921 (H. Schouteden) (MRAC) [not seen]. [Synonymy by Bolton, 1973: 330]

Polyrhachis cubaensis subsp. imatongica Weber, 1943: 388, pl. 16, fig. 22. Syntype workers, SUDAN: Imatong Mts., east slopes, 3800–4000 ft, 24.vii.1939 (N.A. Weber) (MCZ) [not seen]. [Synonymy by Bolton, 1973: 330]

Diagnosis. A viscosa -group species with a uniquely (among all African Polyrhachis ) apically enlarged scape and proximally flattened first funicular joint.

Distinctive features of P. v i s c os a and a comparison with P. omissa are discussed under the latter.

In addition, I give measurements of viscosa workers I examined (n=16): HL 1.58–1.87, HW 1.30–1.59, CI 79–86, SL 1.70–2.15, SI 125–142, FW 0.40–0.50, FI 30–35, PW 1.11–1.47, WL 1.97–2.50, HTL 1.66–2.20.

Material examined. BURKINA FASO: Tanguen (50 km NNE of Ouagadougou), viii.1996 (University of Milano) (1 w, MSNM); Tiogo (140 km W of Ouagadougou), iv.1999 (M. Ouedraogo) (4 w, MSNM). ETHIOPIA: Coromma, x.1892–93 (E. Ruspoli) (7 w, MSNG); Banno, 1.v.1939 (E. Zavattari, Mission Sagan – Omo) (1 w, MSNG); Banno, 7.v.1939 (E. Zavattari, Mission Sagan – Omo) (2 w, MSNG). ERITREA: Bogos, Sciotel, 1870 (O. Beccari) (2 w, MSNG); Bogos, Keren, 1870 (O. Beccari) (1 w, MSNG). KENYA: Laikipia Distr., Mpala Research Centre, 0.28°N 36.87°E, 13.ii.2004, 1600 m (S. Kamande) (5 w, HLMD).

Figures

FIGURE 14. Polyrhachis viscosa, worker (BURKINA FASO, Tiogo (140 km W of Ouagadougou, IV. 1999, (M. Ouedraogo) [sample n ° 3]): A, body profile; B, dorsum of mesosoma; C, head in full-face view. (Photos by M. Zilioli)