Tetraponera pumila Ward 2022, sp. nov.

Tetraponera pumila sp. nov.

(Figs 15, 40)

Type material. Holotype worker: Burundi, Muyinga, Ruvubu National Park, 1382 m, -2.98144 30.45531, 20 Jan 2010 – 4 Feb2010, edge of forest, near Ruvubu R., Malaise trap, R. Copeland (CASENT0863337) (USNM). Paratypes: 4 workers, same data as holotype (CASENT0796550, CASENT0863335, CASENT0863336, CASENT0863338) (CASC, UCDC, USNM).

Worker measurements (n = 10). HW 0.42–0.53, HL 0.54–0.66, LHT 0.30–0.38, CI 0.70–0.83, FCI 0.17–0.22, REL 0.29–0.34, REL2 0.39–0.44, SI 0.46–0.54, SI3 1.12–1.40, FI 0.42–0.49, PLI 0.85–1.01, PWI 0.64–0.85, LHT/ HW 0.67–0.75, CSC 0, MSC 0.

Worker diagnosis. Very small species (HW 0.42–0.53), with moderately elongate head (CI 0.70–0.83); frontal carinae widely separated, the distance between them about twice basal scape width or more (FCI 0.17–0.22, MFC/ SL 0.33–0.44); scape short, about one-half head width (SI 0.46–0.54) and slightly more than one-third of head length (SI2 0.34–0.42); anterior clypeal margin with short, truncate median protrusion, furnished with three blunt denticles (Fig. 15a); profemur moderately robust (FI 0.42–0.49), legs short (LHT /HL 0.49–0.59); metanotal plate conspicuous, about 0.7× the length of the mesonotum, bounded anteriorly by a weak transverse impression and posteriorly by a better developed impression with longitudinal rugulae; dorsal face of propodeum somewhat flattened, rather short, and rounding insensibly into the declivitous face; petiole short, high and rounded (see PLI and PWI values), with a distinct anterior peduncle, a steeply ascending anterior face and more gently descending posterior face (Fig. 15b); in profile, petiole as high as or higher than long; in dorsal view, petiole one-third to two-fifths of head width (DPW /HW 0.34–0.43); postpetiole broader than long (PPW /HW 0.50–0.54). Dorsum of head, mesosoma and petiole with dense reticulate-coriarious sculpture, subopaque; sculpture weakened laterally (sometimes also medially on the frons) and on postpetiole; gaster with weak reticulate-coriarious sculpture, sublucid. Median tooth of clypeal lobe flanked by a distinctive pair of blunt setae, about 0.07 mm long and directed anteroventrally; otherwise standing pilosity very sparse, absent from the dorsum of head (including frontal carinae), mesosoma, petiole, postpetiole, and abdominal tergites 4–6. Dark brown, appendages lighter (Fig. 15).

Comments. This species can be recognized by its small size (worker HW 0.42–0.53); unique clypeal pilosity, consisting of pair of stout setae on the clypeal margin, directed anteroventrally, and no others; short, high petiole; and rather dense sculpture on the dorsum of the head and mesosoma. A single worker from vic. Irangi, Sud-Kuvi, DR Congo, has the upper half of the head more extensively shiny, with scattered punctures, but is otherwise structurally similar to the remaining material. The only other members of the Tetraponera allaborans group in continental Africa that are this small— Tetraponera continua, T. cortina, T. dispar, and T. gerdae —have more extensive clypeal pilosity and a shinier integument.

Distribution and biology. T. pumila is widely distributed, from Ghana to Kenya, south to Zimbabawe, but infrequently collected. Collection sites include evergreen and semideciduous forest. No nest series have been collected.

Material examined (ASIC, BMNH, CASC, FHGC, LACM, SAMC, UCDC, USNM). Burundi: Muyinga: Ruvubu National Park, 1382 m (Copeland, R.); DR Congo: Haut-Katanga: 38 mi E Sandoa, 960 m (Ross, E. S.; Leech, R. E.); Sud-Kivu: vic. Irangi, 900 m (Wagner, T.); Ghana: Eastern: Mampong (Room, P.); Tafo (Collingwood, C. A. [as “ C. A. C.”]); Kenya: Kakamega: Kakamega Forest, 1600 m (Wagner, T.); Kakamega Forest, Busumbuli, 1553 m (Wagner, T.); Kilifi: 20 km WSW Malindi, 20 m (Ward, P. S.); Arabuko Sokoke Forest, 45 m (Hita Garcia, F.; Fischer, G.); Uganda: Masindi: Budongo Forest, vic. Sonso, 1050 m (Wagner, T.); Zimbabwe: Mashonaland Central: Zambesi Valley, 7 km SE Angwa Bridge (Weyrich, J.).