Tetramorium rufescens Stitz, 1923

Mbanyana, Nokuthula, Garcia, Francisco Hita, Robertson, Hamish Gibson & Roux, Johannes Jacobus Le, 2018, A taxonomic revision of seed harvester ants of the Tetramorium solidum group (Hymenoptera: Formicidae) in southern Africa, European Journal of Taxonomy 454, pp. 1-59 : 42-44

Tetramorium rufescens Stitz, 1923

Figs 2H , 3I, M, P , 20 , 24

Tetramorium solidum st. rufescens Stitz, 1923: 163 .

Diagnosis

The following character combination distinguishes T. rufescens from T. glabratum and T. signatum : dorsum of mesosoma with dense reticulate punctate sculpture and propodeal spines long and narrow (PSLI 16–23).

Material examined

Syntypes

NAMIBIA: 3 pinned workers, Swakopmund , 12–19Apr. 1911, W. Michaelsen leg. ( ZMHB: FOCOL 2082 to FOCOL 2084 ).

Other material

NAMIBIA (148 pinned specimens): Spitzkoppe , 21°50′ S, 15°11′ E, 6–7 Mar. 1995, pitfall traps, E.S. Ross and A.R. Stephen leg. ( CASC: CASENT-0217976 (compared with type)); 61.2 km S of Gobabis on C20, at intersection of C20 and D1790, 22°56.806′ S, 18°44.681′ E, 1353 m a.s.l., nesting in red sandy soil, 17 Apr. 2011, N. Mbanyana and H.G. Robertson leg. (SAM-HYM-C027008); Porcupine Camp Site, 2.8 km W of Kamanjab , 19°38.448′ S, 14°45.980′ E, 10 Apr. 2011, nesting in loam soil, entrance in the open, N. Mbanyana and H.G. Robertson leg. (SAM-HYM-C026891); Spitzkopje, 50 mi. E of Hentiesbaai , 950 m a.s.l., 13 Oct. 1967, pitfall traps, H.G. Robertson leg. (SAM-HYM-C007990); Spitzkoppe, 21°50′ S, 15°11′ E, 6–7 Mar. 1995, pitfall traps, H.G. Robertson leg. (SAM-HYM-C007993); Otjozondju, Otjiamongo , 21.60° S, 16.94° E, 1495 m a.s.l., 8 May 2007, C. Grohmann leg. ( SAM- HYM-C027188); Ongongo (= Warmquelle ), 19°10′ S, 13°49′ E, foraging on rocky ground, 10 Mar. 1995, H.G. Robertson leg. (SAM-HYM-C008141); Epupa Falls , 17°00′ S, 13°15′ E, open rocky savanna, H.G. Robertson leg. (SAM-HYM-C009147, SAM-HYM-C009089); Spitzkoppe , 21°50′ S, 15°11′ E, 6–7 Mar. 1995, pitfall traps, H.G. Robertson leg. (SAM-HYM-C007998); Gamsberg Pass , 23.16° S, 16.20° E, 7 Sep. 1987, H.G. Robertson leg. (SAM-HYM-C000496); Naukluft PK, Mirabib , 12 Mar. 1988, collected from nest, H.G. Robertson leg. (SAM-HYM-C001039); Namib Nuakluft Park, Ganab Camp Site , 13 Mar. 1986, collected from nest, H.G. Robertson leg. (SAM-HYM-C001044); SE of Windhoek, M’Bela Farm , on sand, C. Dickman leg. (SAM-HYM-C006260, SAM-HYM-C006263, SAM-HYM-C006265); Hobatere , 15 Mar. 1995, open mopane savanna on granite derived gravelly soils, H.G. Robertson leg. (SAM-HYM-C009193); Hobatere (3 km from gate), Boomrivier , Luderitz District , 28°01′ S, 17°04′ E, 13–26 Nov. 1992, pitfall traps, E. Marais leg. (SAM-HYM-C027181); Daberas, Diamond Area 1, 28°12′ S, 16°49′ E, pitfall trap, 14–29 Sep. 1994, E. Marais leg. (SAM-HYM-C027184); miscellaneous foragers, Opuwo, 3 km from Opuwo Junction on C35, open savanna on red clay soils, pointed termite mounds, 14 Mar. 1995, H.G. Robertson leg. (SAM-HYM-C009186); Klein-Aus Vista , rocky north-facing slope with low shrubs and grass, 26°39.221′ S, 16°14.532′ E, 1325 m a.s.l., soils shallow and gravelly, 5 Apr. 2011 (SAM-HYM-C027006); foragers, Ai-Ais , 27°55′ S, 17°30′ E, 19 Mar. 1995, on gravel/bare ground outside bungalow, H.G. Robertson leg. (SAM-HYM-C009267); Namib Desert, Skeleton Coast , 10 Aug. 1982, collected from a gravel plain, desert, A.C. Marsh leg. ( CASC: CASENT0764595 , CASENT0764596 ); Karibib, Erongo,Central Namib Desert 2010site33, 22.13598°S, 14.86326° E, 596 m a.s.l., hand collected, desert, Central Namib vegetation, 28 Oct. 2010, P. Hawkes, J. Fisher, J. Irish and R. Scholtz leg. ( CASC: CASENT0250971 ).

SOUTH AFRICA: Northern Cape: road from Klein Pella to Orange River, 28.98596° S, 18.99436° E, 615 m a.s.l., 15 Dec. 2007, Eastern Gariep plain desert with deep soils and Euphorbia , found nesting at base of grass tuft, N. Mbanyana and H.G. Robertson leg. (SAM-HYM-C019958); Hopetown Municipal Farm, Hopetown District , 4 km E of Hopetown , 15 Feb. 1997, B. Chambers leg. (SAM-HYM-C011115); Brandvlei , 23 Nov. 1963 (SAM-HYM-C017177); Postmasburg, Oryx Game Farm site 5, pitfall trap, 28.44786° S, 22.13321° E, 1107 m a.s.l., mixed savannah in Gordonia Duneveld , 26 Mar. 2011, D. Pietersen leg. ( CASC: CASENT0250875 ); Postmasburg, SIO-site 4, 27.80767° S, 22.94291° E, 1170 m a.s.l., pitfall trap, ephemeral river bed and adjacent vegetation in Olifantshoek Plains Thornveld , 19 Feb. 2015, P. Hawkes and J. Fisher leg. ( CASC: CASENT0250852 ). – Eastern Cape: Grahamstown , 19 Nov. 1965, A.J. Prins leg. (SAM-HYM-C019173) .

Measurements (worker N =13)

HL 0.983 –1.200 (1.065); HW 0.954 –1.151 (1.021); SL 0.708 –0.856 (0.772); EL 0.266 –0.325 (0.291); PH 0.393 –0.570 (0.460); PW 0.610 –0.777 (0.678); WL 1.003 –1.141 (1.101); PSL 0.167 –0.236 (0.206); PTH 0.315 –0.403 (0.348); PTL 0.275 –0.325 (0.305); PTW 0.295 –0.425 (0.343); PPH 0.315 –0.418 (0.362); PPL 0.226 –0.291 (0.259); PPW 0.369 –0.521 (0.433); OI 27–30 (29); CI 91–100 (96); SI 73–81 (76); DMI 57–69 (62); LMI 36–50 (42); PSLI 16–23 (19); PeNI 46–61 (50); LPeI 78–100 (88) DPeI 97–127 (112); PpNI 59–75 (64); LPpI 59–77 (72); DPpI 154–188 (167); PPI 121–133 (127).

Distribution

Tetramorium rufescens is known from South Africa and Namibia.

Remarks

The description of this species matches that of Bolton (1980), except for colour. We observed some variation in the specimens examined, ranging from red to light brown, in those collected at certain localities in South Africa (Klein Pella) and Namibia (Kamanjab, Luderitz District, Daberas, Hobatere, Epupa Falls). This species has been recorded from the Drakensberg Montane Grasslands, Kalahari Xeric Savanna, Nama Karoo, Namib Desert, Namibian Savanna Woodlands and Succulent Karoo.

Figures

Fig. 2. Body in profile showing pilosity and pubescence. A. T. dichroum Santschi, 1932 (CASENT0746320). B. T. peringueyi Arnold, 1926 (CASENT0250873). C. T. rothschildi (Forel, 1907) (CASENT0764434). D. T. clunum Forel, 1913 (CASENT0764600). E. T. galoanasum Santschi, 1910 (CASENT0915015 – Antweb, William Ericson). F. T. setuliferum Emery, 1895 (MCZ_ENT00512567). G. T. glabratum Stitz, 1923 (SAM-HYM-C024395). H. T. rufescens Stitz, 1923 (CASENT0250852). I. T. solidum Emery, 1886 (CASENT0250960).

Fig. 3. A–B. Waist segments and gaster oblique lateral view. A. T. setuliferum Emery, 1895 (MCZ_ ENT00512567). B. T. clunum Forel, 1913 (CASENT0764600). C–F. Waist segments in dorsal view. C. T. grandinode Santschi, 1913 (CASENT0764655). D. T. lerouxi Mbanyana, Robertson & Hita Garcia sp. nov. (SAM-HYM-C023329). E. T. signatum Emery, 1895 (SAM-HYM-C020573). F. T. glabratum Stitz, 1923 (SAM-HYM-C024395). G–I. Mesosoma in profile. G. T. jordani Santschi, 1937 (CASENT0248475). H. T. glabratum (SAM-HYM-C024395). I. T. rufescens Stitz, 1923 (CASENT0250852). J–M. Head in full-face view. J. T. barbigerum Bolton, 1980 (CASENT0901181). K. T. pogonion Bolton, 1980 (CASTYPE13390 – Antweb, photographer unknown). L. T. glabratum (SAM-HYM-C024395). M. T. rufescens (CASENT0250852). N–P. Waist segments in profile. N. T. duncani Mbanyana, Robertson & Hita Garcia sp. nov. (SAM-HYM-C027003). O. T. glabratum (SAM-HYM-C024395). P. T. rufescens (CASENT0250852).

Fig. 20. Tetramorium rufescens Stitz, 1923 (CASENT0250852). A. Body in profile. B. Body in dorsal view. C. Head in full-face view.

Fig. 24. Map showing the distribution of species in the Tetramorium solidum group.