Tetramorium clunum Forel, 1913

Figs 2D, 3B, 8, 24

Tetramorium setuliferum st. cluna Forel, 1913: 218 .

Diagnosis

In the T. solidum group there are only three species with short, broad, flattened and strongly appressed glittering silvery hairs covering the body (Fig. 2 D–F), namely, T. s etuliferum, T. clunum and T. galoasanum . Tetramorium galoasanum is distinguished from the other two species by its long, dense, overlapping strap-like hairs, whereas in the other two species these hairs are sparse and spaced out. Tetramorium clunum is separated from T. setuliferum by the following characters: (1) first gastral tergite does not overhang the tergosternal suture in profile (Fig. 3B); (2) first gastral tergite is sculptured throughout whereas in T. setuliferum only the base is sculptured; (3) dorsum of head behind clypeus with at least one pair of erect hairs, whereas T. setuliferum lacks elongate erect hairs on the dorsum of head; and (4) tergum of postpetiole without lateral alar prominences, whereas these are present in T. setuliferum .

Material examined

Syntypes

SOUTH AFRICA: workers, Eastern Cape, Willowmore, Dec. 1912, H. Brauns leg. (BMNH: CASENT0901182; MHNG: CASENT0909155).

Other material

SOUTH AFRICA (26 pinned specimens): Eastern Cape: Fish River Valley, Jun. 1965 (SAM- HYM-C004009); Willomore, Sep. 1919, H. Brauns leg. (SAM-HYM-C004010); Willowmore, 33° S, 22° E, 500 m a.s.l., nest in sandy soil, 1 Dec. 1976, C.F. Jacot-Guillarmod leg. (CASC: CASENT0217964; BMNH: CASENT0764600 to CASENT0764602). – Western Cape: Oudtshoorn, Grootkop Nature Reserve, 33.577917° S, 22.217028° E, 373 m a.s.l., 10 Mar. 2006, Succulent Karoo, pitfall trap, B. Braschler leg. (SAM-HYM-C024965); Josephskraal, 33.04182° S, 20.72157° E, 896 m a.s.l., Koedoesberge-Moordenaars Karoo, deep soil on elevated flood plain, 16 Apr. 2008, N. Mbanyana and H.G. Robertson leg. (SAM-HYM-C020467); Nature’s Valley, 33°58′38″ S, 23°33′39″ E, 10 m a.s.l., 8 Dec. 1967, A.J. Prins leg. (SAM-HYM-C015136). – Northern Cape: Melton Wold, 31.46189° S, 22.72417° E, 1331 m a.s.l., 9 Jan. 2009, N. Mbanyana and H.G. Robertson leg. (SAM-HYM-C023304).

Measurements (worker N =11)

HL 0.885 –1.062 (0.958); HW 0.919 –1.090 (0.991); SL 0.688 –0.757 (0.723); EL 0.207 –0.266 (0.239); PH 0.482 –0.570 (0.544); PW 0.570 –0.669 (0.609); WL 0.922 –1.023 (0.963); PSL 0.157 –0.177 (0.168); PTH 0.285 –0.344 (0.307); PTL 0.295 –0.340 (0.315); PTW 0.305 –0.381 (0.325); PPH 0.413 –0.530 (0.461); PPL 0.187 –0.246 (0.207); PPW 0.374 –0.472 (0.401); OI 22–27 (24); CI 101–105 (103); SI 69–76 (73); DMI 61–67 (63); LMI 51–62 (57); PSLI 15–19 (18); PeNI 49–57 (53); LPeI 97–113 (103) DPeI 92–112 (103); PpNI 63–71 (66); LPpI 40–58 (45); DPpI 152–218 (195); PPI 117–127 (124).

Distribution

Tetramorium clunum has been recorded from South Africa (Eastern Cape, Western Cape and Northern Cape) and Namibia, where it occurs in Nama Karoo, Succulent Karoo and Namib Desert.

This is a ground-nesting species. It has been recorded nesting in deep soils. Nothing is known about its feeding behaviour, but presumably this species feeds on seeds, as this is recorded for most other species of this group. This species has been collected in yellow pan traps, pitfall traps and by turning stones.