Tetraponera tessmanni (Stitz)

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 : 38

Tetraponera tessmanni (Stitz)

( Figs 16 , 35 )

Sima tessmanni Stitz 1910: 131 . Syntypes, 2 workers, Alen , Equatorial Guinea (Tessmann) (MHNG, NHMB) [examined]. 1 syntype worker from MHNG imaged on AntWeb: CASENT0907476. Syntypes, 1 dealate queen, 2 workers, Alen, Equatorial Guinea (Tessmann) (ZMHB) [not examined]; imaged on AntWeb: FOCOL1166, FOCOL1167, FOCOL1168.

Viticicola tessmanni var. castanea Wheeler 1922a: 112 . Syntypes, 17 workers, 3 dealate queens, 1 ergatoid queen, Avakubi, Democratic Republic of Congo (H. O. Lang) ( AMNH, LACM, MSNG, MCZC, NHMB, USNM) [examined] . 1 syntype worker from NHMB imaged on AntWeb: CASENT0915540. Synonymy by Brown 1950: 248 .

Tetraponera tessmanni (Stitz) ; Wheeler 1918: 304. Description of larva. Combination in Tetraponera .

Sima Tessmannii Stitz ; Santschi 1919: 84. Description of queen.

Viticola tessmanni (Stitz) ; Wheeler 1919: 130. Combination in Viticicola .

Sima (Tetraponera) tessmanni Stitz ; Emery 1921: 28. Combination in Sima (Tetraponera) .

Viticola tessmanni (Stitz) ; Wheeler 1922a: 109. Combination in Viticicola .

Viticola tessmanni (Stitz) ; Wheeler 1922a: 111. Description of male.

Viticola tessmanni (Stitz) ; Wheeler & Wheeler 1956: 391. Description of larva.

Tetraponera tessmanni (Stitz) ; Ward 1990: 489. Combination in Tetraponera .

Tetraponera tessmanni (Stitz) ; Chomicki et al. 2015: figure S1. Placement in molecular phylogeny.

Tetraponera castanea (Wheeler) ; Ward 1990: 489. Combination in Tetraponera , as junior synonym of T. tessmanni .

Worker measurements (n = 10). HW 0.58–0.66, HL 0.73–0.80, LHT 0.42–0.47, CI 0.76–0.84, FCI 0.20–0.24, REL 0.20–0.24, REL2 0.24–0.31, SI 0.41–0.44, SI3 1.42–1.73, FI 0.45–0.50, PLI 1.06–1.21, PWI 0.84–0.98, LHT/ HW 0.69–0.73, CSC 2–7, MSC 5–8.

Worker diagnosis. Small species (HW 0.58–0.66, LHT 0.42–0.47); head broad, with rounded sides ( Fig. 16a ), and small flattened eyes (REL 0.20–0.24); palp formula 4p3,3 or 3,3; frontal carinae widely separated, the minimum distance between them about one-half scape length; scape very short, less than one-half head width (SI 0.41–0.44, SI2 0.32–0.37); anterior clypeal margin broadly convex, straight or weakly immarginate medially, edentate; profemur short and robust (FL/HW 0.67–0.70, FI 0.45–0.50), hind legs short (LHT/HL 0.56–0.59); mesopropodeal groove long and deeply impressed ( Fig. 16b ); dorsal face of propodeum strongly convex in profile, and rounding insensibly into the longer declivitous face; petiole short, high, and broad (see petiolar indices), rounded in profile and with a prominent ventral process, becoming thin and lamellate anteroventrally ( Fig. 16b ); postpetiole broader than long. Integument smooth and shiny, with scattered fine punctures, becoming weakly reticulate on the lower half of the mesopleuron and metapleuron; mesopropodeal groove irregularly rugulose. Standing pilosity present as scattered long hairs on the head (CSC 2–7), mesosoma (MSC 5–8), petiole, postpetiole, and gaster, accompanied on most of body by a dense underlying subdecumbent pubescence that grades into short suberect pilosity. Varying in color from light yellowish- or orange-brown to medium brown.

Comments. Among African Tetraponera the worker of this species is easily recognized by its diminutive size, very small eyes (REL 0.20–0.24), short scapes and legs, deep mesopropodeal impression, and short, broad petiole with prominent ventral extension. For a discussion of the relationship to T. mayri see under that species.

Distribution and biology. Known from Ghana to DR Congo, T. tessmanni is an obligate inhabitant of the myrmecophytic liana Vitex thyrsiflora ( Bequaert 1922; Wheeler 1922a; Schnell & Grout de Beaufort 1966). The colonies of T. tessmanni inhabit live stems of the vine, and the aggressive stinging workers actively patrol the foliage of the plant, providing an effective deterrent to herbivory ( Djiéto-Lordon et al. 2005). The ants are thought to derive all or most of their nutrition from the plant itself, by feeding on callus tissue which develops in ant-excavated cavities in the internal wall of the vine ( Bailey 1922). Examining pellets from the trophothylax (food-pouch) of T. tessmanni larvae, Wheeler & Bailey (1920) found plant tissue, spores, hyphae, and remains of other larvae. Colonies of T. tessmanni are polygynous, and there is considerable variation in queen size, including ergatoid and subapterous forms, as well as normal dealate queens ( Wheeler 1922a: 108).

Material examined ( AMNH, CASC, CPDC, CUIC, DZUP, LACM, MCZC, MHNG, MSNG, NHMB, PSWC, SAMC, UCDC, USNM). Cameroon: Est: Masea (McKey, D.) ; Sud-Ouest: Nta Ali Forest Reserve, Mbio , sul de Mamfé (Blatrix, R.) ; Central African Republic: Sangha-Mbaéré: 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 (van Noort, S.); P.N. Dzanga-Ndoki, Mabéa Bai, 21.4 km 53° NE Bayanga, 510 m (Fisher, B. L.) ; DR Congo: Haut-Uélé: Medje (Lang, H. O.); Medje (c.u.); province unknown: “Congo Belge” (c.u.); Tshopo: Avakubi (Lang, H. O.) ; Equatorial Guinea: Wele-Nzas: Alen (Tessman, G.) ; Gabon: Woleu-Ntem: 20.5 km 110° ESE Minvoul , 600 m (Fisher, B. L.) ; Ghana: Eastern: Pimpimso (Box, H. E.) .

Figures

FIGURES 16–18. Tetraponera allaborans group, workers, full-face (dorsal) view of head (a) and lateral profile of body (b). 16, T. tessmanni, Cameroon (CASENT0794354); 17, T. hysterica, Madagascar (CASENT0012842); 18, T. longula, Madagascar (CASENT0012843). Images from AntWeb (www.antweb.org); photographers Matthew Prebus (16), April Nobile (17, 18).

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).