Tetraponera penzigi (Mayr) (Figs 14, 39) Sima Penzigi Mayr 1907: 10. Syntypes, 9 workers, 2 alate queens, 2 males, Usambara, Tanzania (Sjöstedt) (NHMV), 2 workers, Kahe, Kilimanjaro, Tanzania [as “Kilim.”] (Sjöstedt) (NHMV), 1 worker, Kahe, Kilimanjaro [as “Kilimand.”], Tanzania (Sjöstedt) (MHNG) [examined]. 1 worker syntype from NHMV imaged on AntWeb: CASENT0915851. Syntypes, 3 workers, Usambara, Tanzania (Sjöstedt) (ZMHB) [not examined]; imaged on AntWeb: FOCOL1155, FOCOL1156, FO- COL1157. Tetraponera scotti Donisthorpe 1931: 498. Syntypes, 1 worker (head only), 1 dealate queen, Dyem-Dyem Forest, 8000–9000 ft., Ethiopia (H. Scott) (BMNH) [examined]. Imaged on AntWeb: CASENT0902911, CASENT0902818. Syn. nov. Tetraponera penzigi v. praestigiatrix Santschi 1937a: 50. Syntype, 1 dealate queen, Dongabesh [as “ Dongerbeach ”], Mbulu Dist., 5500 ft., Tanzania (B. D. Butt) (NHMB) [examined]. Imaged on AntWeb: CASENT0915538. Syn. nov. Sima (Tetraponera) zavattarii Menozzi 1939: 99. Syntypes, 3 workers, Mega, Ethiopia (E. Zavattari), 1 worker, Neghelli, Ethiopia (E. Zavattari) (IEGG) [examined]. Syn. nov. Sima (Tetraponera) Penzigi Mayr; Arnold 1916: 180. Combination in Sima (Tetraponera). Tetraponera penzigi (Mayr); Wheeler 1922b: 800. Combination in Tetraponera. Tetraponera penzigi (Mayr); Chomicki et al. 2015: figure S1. Placement in molecular phylogeny. Tetraponera penzigi praestigiatrix Santschi; Ward 1990: 489. Subspecies of penzigi. Tetraponera zavattarii (Menozzi); Ward 1990: 489. Combination in Tetraponera. Worker measurements (n = 12). HW 0.62–0.83, HL 0.78–1.05, LHT 0.50–0.72, CI 0.78–0.82, FCI 0.20–0.25, REL 0.29–0.33, REL2 0.36–0.43, SI 0.47–0.53, SI3 1.22–1.35, FI 0.40–0.46, PLI 0.80–0.95, PWI 0.69–0.84, LHT/ HW 0.77–0.88, CSC 0, MSC 0. Worker diagnosis. Small to medium in size, with broad head (CI 0.78–0.82); frontal carinae well separated, the minimum distance between them one-fifth to one quarter of head width (FCI 0.20–0.25, MFC/EL 0.50–0.65, MFC/ SL 0.40–0.52); scape short, about one-half head width (SI 0.47–0.53) and two-fifths of head length (SI2 0.38–0.41); anterior clypeal margin with a broadly convex, crenulate medial protrusion (Fig. 14a); profemur relatively slender (FI 0.40–0.46), legs relatively long (LHT/HW 0.77–0.88, LHT/HL 0.61–0.72); metanotal plate conspicuous, about one-half to two-thirds the length of the mesonotum, and bounded anteriorly and posteriorly by transverse impressions that are longitudinally rugulose; dorsal face of propodeum flattened, laterally submarginate, as long as or longer than the declivitous face, and weakly differentiated from the latter; petiole relatively short, high and rounded (see PLI and PWI values), with a distinct anterior peduncle and without well differentiated anterior, dorsal and posterior faces (Fig. 14b); in profile, petiole not quite as high as long; in dorsal view, petiole two-fifths to one-half of head width (DPW/HW 0.40–0.50); postpetiole broader than long (PPW/HW 0.48–0.57). Dorsum of head and mesosoma predominantly reticulate-coriarious and opaque, becoming more weakly sculptured and sublucid laterally, and on petiole, postpetiole, and gaster. Standing pilosity very sparse, absent from the dorsum of head, mesosoma, petiole, postpetiole, and abdominal tergites 4–6. Dark brown to brownish-black, antennae and mandibles lighter. Comments. This species can be recognized by its broad head (worker CI 0.78–0.82, queen CI 0.64–0.68), well separated frontal carinae, relatively long legs (worker LHT/HW 0.77–0.88, queen LHT/HW 0.94–1.01), and distinctive sculpture: dorsum of head and mesosoma finely but densely reticulate-coriarious and opaque. Related species have a shinier integument, and either a more elongate head and more closely adjacent frontal carinae (T. continua, T. cortina, T. gerdae), or shorter legs (T. pedana). T. penzigi also has larger workers, on average, than these other species. Distribution and biology. Tetraponera penzigi occurs from southern Ethiopia to Tanzania, and lives only in the swollen stipular thorns of Vachellia drepanolobium. It interacts in a distinctive manner with its hostplant, differing in colonization ability, spatial distribution, competitive ability, and herbivore deterrence from two species of Crematogaster that are also obligate residents of V. drepanolobium (Hocking 1970; Young et al. 1997; Stanton et al. 2002; Baker et al. 2017; Boyle et al. 2019). The record of T. penzigi nesting in Stereospermum dentatum (Bignoniaceae) (Penzig 1895) refers to the closely related species, T. gerdae. Material examined (BMNH, CASC, CUIC, FHGC, HZIC, IEGG, LACM, MHNG, NHMB, NHMW, NMKE, PSWC, SAMC, STDC, UCDC, USNM). Ethiopia: Oromia: Dyem-Dyem Forest, 2590 m (Scott, H.); Mega (Zavattari, E.); Neghelli (Zavattari, E.); Kenya: Kajiado: 26 mi SW Nairobi, 1615 m (Irwin, M. E.; Ross, E. S.); 60 mi S Nairobi, on Nmanga Rd. (DeMasi, V.); Oloitokitok [as “ N Loitokitok (= Oloit.)”], 1800 m (Zettel, H.); Laikipia: 30 km S Mpala Res. Centre, 1650 m (Warui, C.; Abonyo, E.); 4 km SNW [sic] Mpala Research Centre, 1750 m (Snelling, R. R.); Mpala, 1800 m (Palmer, T.); Mpala Farm, 1800 m (Stanton, M. L.); Mpala Research Centre, 1650 m (Snelling, R. R.); vic. Mpala Farm, 1800 m (Isbell, L.); Machakos: Hopcrofts Game Ranch, Athi River (Stapley, L.); Marsabit: Mt. Kulal, 885 m (Stager, K. E.); Nairobi City: Kitengela (Martins, D. J.); Nairobi, 2 mi S airport (Janzen, D. H.); Nakuru: Hell’s Gate Nat. Park (Zdárková, E.); Nyeri: Burguret (Strobele); Mweiga (Hogue, C. L.); Samburu: Segera Ranch, Laikipia Plateau (Pruetz, J.); Tanzania: Arusha: Ardai (Hocking, B.); Arusha (Mann, W. M.); Kilimanjaro: Kahe, Kilimanjaro [as “Kilim.”] (Sjöstedt); Kahe, Kilimanjaro [as “ Kilimand. ”] (c.u.); Sanya (Hocking, B.); Manyara: Dongabesh [as “Dongerbeach”], 1675 m (Butt, B. D.); Lake Manyara (Sibley, G.); Umbulu (Mann, W. M.); Mara: Serengeti Visitor Center (Dash, S. T.); Tanga: Usambara [as “Usumbara”] (c.u.); Usambara [as “Usumbara”] (Sjöstedt); Uganda: district unknown: Karamodja [= Karamoja Province] (Hamann).

Published as part of Ward, Philip S., 2022, The ant genus Tetraponera (Hymenoptera: Formicidae) in the Afrotropical region: taxonomic review and key to species, pp. 1-70 in Zootaxa 5102 (1) on pages 35-36, DOI: 10.11646/zootaxa.5102.1.1, http://zenodo.org/record/6245602