Tetraponera aethiops F. Smith

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 : 61-62

Tetraponera aethiops F. Smith

( Figs 33 , 45 )

Tetraponera Aethiops F. Smith 1877: 71 . Syntype, 1 worker, “ S. Africa ” (BMNH) [examined]. Imaged on AntWeb : CASENT0902813.

Sima spininoda André, 1892: 51 . Syntypes, 10 workers, 3 alate queens, Gabon (Mocquerys) ( MHNG, MNHN, NHMV) [examined] . 1 syntype worker from MNHN imaged on AntWeb: CASENT0913718. Synonymy by Emery 1912:97 .

Sima aethiops (F. Smith) ; Dalla Torre 1893: 53. Combination in Sima .

Sima aethiops (F. Smith) ; Santschi 1911c: 207. Description of male.

Sima (Pachysima) aethiops (F. Smith) ; Emery 1912: 97, 98. Combination in Sima (Pachysima) ; description of larva; description of queen.

Pachysima aethiops (F. Smith) ; Wheeler 1918: 305. Combination in Pachysima ; description of larva.

Tetraponera aethiops (F. Smith) ; Ward 1990: 487. Combination in Tetraponera .

Tetraponera aethiops (F. Smith) ; Chomicki et al. 2015: figure S1. Placement in molecular phylogeny.

Sima (Pachysima) spininoda André ; Stitz 1916: 374. Combination in Sima (Pachysima) .

Pachysima spininoda (André) ; Wheeler 1922b: 801. Combination in Pachysima (implied), as junior synonym of P. aethiops . Tetraponera spininoda (André) ; Ward 1990: 487. Combination in Tetraponera , as junior synonym of T. aethiops .

Worker measurements (n = 10). HW 1.70–2.17, HL 1.72–2.35, LHT 1.50–2.08, CI 0.92–0.99, FCI 0.21–0.25, REL 0.27–0.30, REL2 0.28–0.32, SI 0.49–0.53, SI3 1.60–1.86, FI 0.32–0.36, PLI 0.62–0.74, PWI 0.79–0.88, LHT/ HW 0.86–0.97, CSC 6–12, MSC 1–7.

Worker diagnosis. Large, robust species; frontal carinae separated by a distance equal to one quarter of head width or less; clypeus not produced as a median lobe, its anterior margin straight, very weakly convex, or slightly concave ( Fig. 33a ); profemur slender (FI 0.32–0.36), legs moderately long (LHT/HL 0.84–0.91); mesopropodeal impression well marked in profile; dorsal face of propodeum broad and flat, rounding gradually into declivitous face; petiole short and broad, with a short anterior peduncle; postpetiole broader than long; anteroventral petiolar tooth usually spiniform and relatively slender (sometimes triangular), typically followed by a second weaker tooth behind; venter of postpetiole with small, spiniform tooth at anterior margin and, posterior to this, a more prominent rounded boss, directed anteroventrally ( Fig. 33b ). Mandibles longitudinally rugulose and opaque. Most of body covered with fine, dense punctures (and associated pubescence) and subopaque, such sculpture being more weakly developed on the upper part of the head, which is correspondingly shinier. Standing pilosity sparse (MSC 1–7), absent from propodeum, and from extensor surfaces of tibiae. Dark brownish-black, appendages dark to medium brown.

Comments. Workers of T. aethiops are readily distinguished from those of their sister species, T. latifrons , by their rugulose mandibles, less widely separated frontal carinae, sparse pilosity, and longer legs. In T. latifrons the mandibles are smooth and shiny, the frontal carinae are more widely separated (FCI 0.28–0.35 versus 0.21–0.25 in T. aethiops ), standing pilosity is conspicuous on the mesosoma dorsum (MSC 27–45 versus 1–7 in T. aethiops ), and the legs are shorter (LHT/HW 0.76–0.81 versus 0.86–0.97 in T. aethiops ). In addition, in T. latifrons the anteroventral teeth of both the petiole and postpetiole are better developed, yet unaccompanied by additional teeth or protuberances in a more posterior position on each segment, as seen in T. aethiops .

Distribution and biology. In the original description the type locality is stated to be “S. Africa” ( Smith 1858) but this is almost certainly an error. Tetraponera aethiops occurs in wet tropical forest from Nigeria to DR Congo and western Uganda, and is an obligate inhabitant of two myrmecophytic species of Barteria (Passifloraceae) ( Bequaert 1922; Kokolo et al. 2019) that do not occur in South Africa. T. aethiops has also been recorded ( Stitz 1910) nesting in live stems of Heinsia myrmoecia (Rubiaceae) , but Davidson & McKey (1993) cast doubt on this report, noting that the internodal swellings of that plant are too small to support a large ant species such as T. aethiops . As a result of their painful sting, aggressive behavior, and habit of pruning encroaching vegetation, T. aethiops workers provide effective protection of Barteria against herbivores and competing plants ( Janzen 1972; McKey 1974; Dejean et al. 2008), although the pruning behavior may have the primary effect of reducing competition with other ants ( Yumoto & Maruhashi 1999). Recent studies of this system have included examination of population structure in the ant and its hostplant ( Blatrix et al. 2017), and confirmation that fungal “gardens” in the plant domatia provide additional nutritional benefits to the ants beyond those obtained from cohabiting scale insects ( Blatrix et al. 2012; Kokolo et al. 2016).

Material examined ( AMNH, BMNH, CASC, CMNH, CPDC, CUIC, LACM, MCZC, MHNG, MNHN, MSNG, NHMB, NHMW, PSWC, SAMC, UCDC, USNM). Cameroon: Centre: Metet (Good, A. I.); Metet (Schwab, G.); Yaounde (Van Zwaluwenburg; McGough); Yaoundé (c.u.); Littoral: Edéa [as “Edia”] (Schwab, G.); region unknown: “Cameroun” (c.u.); “Kamerun” (Conradt, L.); Sud: Ebolowa, Nkoemvon (Jackson, D.); Efulen (Grissett, F.); Kribi (Johnson, S. E.); Lolodorf (Good, A. I.); Nkoem-Vone (Collingwood); Réserve de Campo, 40 m (Olson, D. M.); Sud-Ouest: Bakingili, 10 m (DiGiulio, J. A.); Iriba Inene, Korup National Park (Blatrix, R.); Korup Natl. Park, 320 m (Koch, G.); Korup, K11 (Jackson, D.); Limbe [as “Victoria”] (Buchholz); Mabete, Victoria Div. (Malkin, B.); Matute, Tiko Plantation (Malkin, B.); Moliwe [as “Molive”] (c.u.); Mundemba (McKey, D.); Rengo Camp, Korup National Park (Blatrix, R.); Central African Republic: Lobaye: Boda (Charleuf, P.); Sangha-Mbaéré: Nola (Le Moult); P.N. Dzanga-Ndoki, 21.4 km 53° NE Bayanga, 510 m (van Noort, S.); P.N. Dzanga-Ndoki, 38.6 km 173° S Lidjombo, 350 m (Fisher, B. L.); P.N. Dzanga-Ndoki, 38.6 km 173° S Lidjombo, 350 m (van Noort, S.); P.N. Dzanga-Ndoki, 5.9 km 72° ENE Bayanga, 410 m (Fisher, B. L.); P.N. Dzanga-Ndoki, Mabéa Bai, 21.4 km 53° NE Bayanga, 510 m (Fisher, B. L.); Res. Dzanga-Sangha, 12.7 km 326° NW Bayanga, 420 m (Fisher, B. L.); Res. Dzanga-Sangha, 12.7 km 326° NW Bayanga, 420 m (van Noort, S.); DR Congo: Équateur: Lingunda (Mairesse, L.); Haut-Uélé: Ambelokudi (Lang, H. O.); Ambelokundi (Lang, H. O.); Bafwaboka (Lang, H. O.); Medje (Lang, H. O.); Medje (Lang; Chapin); Paulis (c.u.); Uélé, Tuku (van den Plas, P.); Ituri: Epulu (Bradley, J. C.); Epulu, 950 m (Ross, E. S.; Leech, R. E.); Maniema: 62 mi E Kibombo (Ross, E. S.; Leech, R. E.); Nord-Kivu: 39 km S Walikale (Ross, E. S.; Leech, R. E.); province unknown: “Congo” (Kohl); Nyangme à Stanleyville (Fauconnet); Sud-Kivu: 45 mi E Kama, 750 m (Ross, E. S.; Leech, R. E.); Tshopo: Avakubi (c.u.); Avakubi (Lang, H. O.); Isangi (Lang, H. O.); Kisangani [as “Stanleyville”] (c.u.); Kisangani [as “Stanleyville”] (Kohl, H.); Kisangani [as “Stanleyville”] (Lang, H. O.); Panga (Lang, H. O.); Equatorial Guinea: Litoral: Eloby (Brauns); Eloby (c.u.); Eloby [as “Elaby”] (Brauns); province unknown: Bioko [as “Fernando Po”] (c.u.); Bioko [as “Fernando Poo”] (Conradt); Riv. San Benito (Guiral); Gabon: Estuaire: Kouame, E. of Libreville (Ross, E. S.); Moyen-Ogooué: Sam Kita (Faure, F.); Ogooué-Ivindo: M’Passa, near Makokou (Fisher, B. L.); Ogooué-Maritime: Res. Monts Doudou, 24.3 km 307° NW Doussala, 375 m (Fisher, B. L.); Res. Moukalaba, 12.2 km 305° NW Doussala, 110 m (Fisher, B. L.); province unknown: “Gabon” (c.u.); “Gabon” (Mocquerys); “Gabun” (Staudinger); Woleu-Ntem: 27.6 km 108° ESE Minvoul, 600 m (Fisher, B. L.); 31.3 km 108° ESE Minvoul, 600 m (Fisher, B. L.); Nigeria: Cross River: Calabar (Usua, E. J.); Delta: Ofore (Carnes, M. A.); Edo: Ogbesse Benin (Box, H. E.); Sapoba For. Reserve, 20 km S Benin City (Janzen, D. H.); Ogun: Alo, 70 mi E Lagos (Lamborn, W. A.); Ondo: Ifon (Simpson, J. J.); Osun: Ifetedo (Biues, D. J.); Republic of Congo: Likouala: 25 km NW Boha, 30 km SE Lac Telle (Alpert, G. D.); Uganda: Bundibugyo: Kirumia River Trail, Semliki Natl. Park, 720 m (Ward, P. S.); Sempaya, Semliki Natl. Park, 680 m (Ward, P. S.); Semuliki National Park, 676 m (Fisher, B. L.; et al.); Kabarole: Fort Portal (Osmaston, H. A.); unknown: “S. Africa” (c.u).

Figures

FIGURES 33–34. Tetraponera rufonigra group workers, full-face (dorsal) view of head (a) and lateral profile of body (b). 33, T. aethiops, Uganda (CASENT0794322); 34, T. latifrons, DR Congo (CASENT0217593). Images from AntWeb (www.antweb. org); photographers Matthew Prebus (33), Estella Ortega (34).

FIGURES 41–46. Distribution maps for Afrotropical Tetraponera. 41, T. andrei (circles), T. anthracina (triangles), T. insularis (square); 42, T. caffra (circles), T. redacta (triangles); 43, T. mocquerysi (circles), T. schulthessi (triangles); 44, T. natalensis (circles), T. setosa (triangle); 45, T. aethiops (circles), T. kosi (triangle); 46, T. latifrons (circles).