Tetraponera exactor, Ward, 2022

Ward, Philip S., 2022, The ant genus Tetraponera (Hymenoptera: Formicidae) in the Afrotropical region: taxonomic review and key to species, Zootaxa 5102 (1), pp. 1-70 : 31

Tetraponera exactor sp. nov.

( Figs 9 , 37 )

Type material. Holotype queen: South Africa, Western Cape, Nature’s Valley at Groot Rivier , 33°58′S 23°33′E, 15–17 Oct 1994, R. Danielsson, loc. 21 ( CASENT0794350 ) ( SAMC).

Queen measurements (n = 1). HW 0.55, HL 0.70, LHT 0.43, CI 0.79, FCI 0.19, REL 0.29, REL2 0.37, SI 0.56, SI3 1.50, FI 0.37, PLI 0.53, PWI 0.46, LHT/HW 0.79, CSC 4, MSC16.

Queen diagnosis. Relatively small species ( HW 0.55); head moderately elongate, with broadly rounded sides; median clypeal lobe bluntly bidentate; frontal carinae well separated, the distance between them much greater than basal scape width ( FCI 0.19); scape short (SI 0.56), somewhat expanded apically; profemur slender (FI 0.37); dorsal face of propodeum rounding gently into declivitous face, both of similar length; petiole elongate ( PLI 0.53), with differentiated anterior peduncle and weak anteroventral tooth ( Fig. 9b ); postpetiole longer than broad, lacking anteroventral process. Integument smooth and shiny, with scattered fine punctures. Standing pilosity present on frontal carinae and as two long posterolateral pairs (0.14–0.17 mm long) on upper half of head; scattered standing pilosity also present on pronotum (10 setae), mesoscutum (5), propodeum (1), petiole (4), postpetiole (4), and succeeding abdominal segments. Light yellowish-brown.

Comments. This species is evidently closely related to Tetraponera clypeata and T. emeryi . The queen of T. exactor differs from those of T. clypeata and T. emeryi by its smaller size (HW 0.55, versus 0.63–0.80 [n = 12] in queens of the other species), more broadly rounded head (CI 0.79, versus 0.67–0.72), more widely separated frontal carinae (FCI 0.19, versus 0.11–0.17), shorter but apically expanded scape (SI 0.56, versus 0.57–0.66), smoother integument, and more abundant standing pilosity. In T. exactor standing hairs are conspicuous on the mesosoma, petiole and postpetiole (MSC 16; Fig. 9b ) whereas in queens of T. clypeata and T. emeryi standing hairs are very sparse to absent on these structures (MSC 0–6).

Distribution and biology. This species is known only from a single alate queen collected in Nature’s Valley, Western Cape, South Africa. No workers have been found that could be attributed to this species, suggesting that it might be a workerless social parasite. Traits indicative of social parasitism include the small size, shiny integument, and increased amounts of standing pilosity compared to related congeners. T. emeryi is sympatric with T. exactor at Nature’s Valley and is a potential host species.

Material examined. Known only from the holotype.

Figures

FIGURES 7–9. Tetraponera allaborans group, full-face (dorsal) view of head (a) and lateral profile of body (b). 7, T. dispar, worker, holotype, Republic of Congo (CASENT0888518); 8, T. emeryi, worker, South Africa (CASENT0220743); 9, T. exactor, alate queen, holotype, South Africa (CASENT0794350). Images from AntWeb (www.antweb.org); photographers Peter Hawkes (7), Matthew Prebus (8, 9).

FIGURES 35–40. Distribution maps for Afrotropical Tetraponera. 35, T. clypeata (circles), T. tessmanni (triangles); 36, T. emeryi (circles), T. dispar (triangle); 37, T. exactor (circle), T. furtiva (triangle), T. liengmei (squares); 38, T. continua (circles), T. cortina (triangles), T. gerdae (squares); 39, T. pedana (circles), T. penzigi (triangles); 40, T. pumila (circles).