Tetraponera cortina, 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 : 28-29

Tetraponera cortina sp. nov.

( Figs 6 , 38 )

Type material. Holotype worker: DR Congo, Tshopo, Yangambi Reserve , 1949, A. Raignier & J. van Boven ( CASENT0794352 ) ( MCZC) . Paratypes: series of 9 workers, same data as holotype ( MCZC, UCDC). The workers have code numbers as follows: “C. 1943” (2 paratype workers), “C. 1944” (2 paratype workers), “C. 1945” (2 paratype workers), “C. 1961” (1 holotype worker, 1 paratype worker), and “C. 1962” (2 paratype workers). The significance of these code numbers is unclear; they might represent different collections or colony series.An inquiry to the Musée Royal de l’Afrique Centrale (Tervuren) about Raignier and van Boven collection numbers yielded no information .

Worker measurements (n = 5). HW 0.49–0.52, HL 0.69–0.71, LHT 0.37–0.40, CI 0.70–0.73, FCI 0.12–0.15, REL 0.27–0.30, REL2 0.38–0.43, SI 0.46–0.52, SI3 1.17–1.37, FI 0.46–0.49, PLI 0.82–0.91, PWI 0.69–0.76, LHT/ HW 0.73–0.78, CSC 0, MSC 0.

Worker diagnosis. Small species ( HW 0.49–0.52), with moderately elongate head (CI 0.70–0.73); frontal carinae separated by no more than 0.15× head width ( FCI 0.12–0.15, MFC/SL 0.26–0.31); scape short, about one-half head width (SI 0.46–0.52) and one-third of head length (SI2 0.33–0.37); anterior clypeal margin with a short, crenulate medial protrusion ( Fig. 6a ); profemur robust (FI 0.46–0.49), legs short ( LHT /HL 0.53–0.57); metanotal plate conspicuous, about four-fifths the length of the mesonotum, and bounded anteriorly and posteriorly by transverse impressions with longitudinal rugulae; dorsal face of propodeum flattened, laterally submarginate, shorter than the declivitous face, and rounding insensibly into the latter; petiole short, high and rounded (see PLI and PWI values), with a distinct anterior peduncle and without well differentiated anterior, dorsal and posterior faces ( Fig. 6b ); in profile, petiole height subequal to height of propodeum and about one-half head width ( PH /HW 0.48–0.57); in dorsal view, petiole slightly more than two-fifths of head width ( DPW /HW 0.41–0.46), and notably less broad than postpetiole ( DPW /PPW 0.72–0.79); postpetiole broader than long and more than one-half head width ( PPW /HW 0.53–0.63). Head and mesosoma predominantly smooth and shiny with scattered punctures and faint reticulation, the latter better developed on the side of the mesosoma; petiole, postpetiole and gaster mostly smooth and shiny. Standing pilosity very sparse, absent from the dorsum of head, mesosoma, petiole, postpetiole, and abdominal tergites 4–6. Medium to dark brown, appendages lighter.

Comments. Workers of this small species are similar to those of T. continua and T. gerdae , but can be recognized by their shinier head, more closely adjacent frontal carinae, and shorter legs (see measurements cited in the key). In addition, the petiole tends to be narrower relative to the postpetiole in T. cortina , such that DPW/PPW 0.72–0.79, as opposed to 0.75–0.94 in T. continua and T. gerdae . Workers of T. pedana also have a shiny integument and short legs, but they can be distinguished from those of T. cortina by their broader head (CI 0.82–0.86 versus 0.70–0.73 in T. cortina ) and more widely separated frontal carinae (FCI 0.19–0.21 versus 0.12–0.15 in T. cortina ). A small alate queen (HW 0.47, LHT 0.40) from Gabon, with shiny vertex, moderately elongate head (CI 0.64) and closely adjacent frontal carinae (FCI 0.17), and a small male (HW 0.45, LHT 0.39) with shiny head from Central African Republic, are considered likely to be conspecific with the T. cortina workers from DR Congo.

Distribution and biology. Tetraponera cortina is known only from the type series collected in central DR Congo and probable alates from Gabon and Central African Republic (see above). The collections come from lowland rainforest, but nothing further is known about the biology.

Material examined. Type series cited above, plus the following specimens provisionally identified as T. cortina : Central African Republic: Sangha-Mbaéré: Parc National Dzanga-Ndoki, Mabéa Bai , 21.4 km 53° NE Bayanga, 510 m (van Noort, S.) (1 male, sweeping, rainforest, marsh clearing) ( CASENT0092903 ) ( CASC) ; Gabon: Ogooué-Maritime: Réserve des Monts Doudou , 25.2 km 304° NW Doussala, 660 m (van Noort, S.) (1 alate queen, swept from low canopy in coastal lowland rainforest) ( CASENT0170712 ) ( CASC) .

Figures

FIGURES 4–6. Tetraponera allaborans group, workers, full-face (dorsal) view of head (a) and lateral profile of body (b). 4, T. clypeata, South Africa (CASENT0220741); 5, T. continua, The Gambia (CASENT0794348); 6, T. cortina, holotype, DR Congo (CASENT0794352). Images from AntWeb (www.antweb.org); photographer Matthew Prebus.

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).