Tetraponera inermis , Ward, P. S., 2009

Ward, P. S., 2009, The ant genus Tetraponera in the Afrotropical region: the T. grandidieri group (Hymenoptera: Formicidae)., Journal of Hymenoptera Research 18, pp. 285-304: 297-298

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Tetraponera inermis

sp. n.

Tetraponera inermis  HNS  sp. n.

(Figs 5, 15-16, 25)

Tetraponera  HNS  psw81; Fisher 1996:100; Fisher 1999: 134. Cited in faunal inventories.

Holotype worker. MADAGASCAR Toamasina : 1 km SSW Andasibe (= Perinet ), 920 m, 18°56'S 48°25'E, 16.xi.1990, ex rotten stick on ground, rainforest, P. S. Ward #10941 ( CASENT0012862) ( CASC). 

Paratypes. Series of workers and queens, same locality as holotype, 16.xi.1990 and 12.xii.1990 (P. S. Ward#10940, 19041, 11143) ( BMNH, CASC, MCZC, PSWC, SAMC, UCDC)  .

Material Examined.-( BMNH, CASC, CUIC, MCZC, NHMV, PSWC, SAMC, UCDC) MADAGASCAR Fianarantsoa: 43 km S Ambalavao, Res. Andringitra, 825 m (Fisher, B. L.); 8 km E Kianjavato, 145 m (Alpert, G.); FC Vatovavy, 175 m (Fisher, B. L.; et al.); Manombo, 30 m (Fisher, B. L.; et al.); R.S. Ivohibe, 7.5 km ENE Ivohibe, 900 m (Fisher, B. L.); Vevembe, 600 m (Fisher, B. L.; et al.); Toamasina: 1 km SSW Andasibe (= Périnet), 920 m (Ward, P. S.); Andasibe ( Périnet) (Brooks, R. W.); F.C. Andriantantely, 530 m (Ratsirarson, H. J.); Mont. Anjanaharibe, 18.0 km 21° NNE Ambinanitelo, 470 m (Fisher, B. L.; et al); Permet ( Noyés, J. S.; Day, M. C); PN Zahamena, 860 m (Fisher, B. L.; et al.); PN Zahamena, Sahavorondrano River, 765 m (Fisher, В. L.; et al.); Res. PerinetAnalamazotra, 930-1040 m (Oison, D. M.); Res. Perinet-Analamazotra, 950 m (Oison, D. M.); vie. Andasibé (=Perinet), 950-980 m (Brown, W. L.; Brown, D. E.); Toliara: 10 km NW Enakara, Rés. Andohahela, 430 m (Fisher, В. L.); 10 km SSW Eminiminy, 750 m (Rajeriarison, E.); 11 km NW Enakara, Rés. Andohahela, 800 m (Fisher, В. L.); 5 km NNW Isaka-Ivondro, Rés. Andohahela, 280 m (Ward, P. S.); 5 km WNW Mandiso, Res. Andohahela, 400 m (Rajeriarison, E.); 5 km WNW Mandiso, Rés. Andohahela, 400 m (Ward, P. S.); 6 km SSW Eminiminy, 250 m (Alpert, G. D.); 6 km SSW Eminiminy, 250 m (Rabeson, P.); 6 km SSW Eminiminy, 250 m (Rajeriarison, E.); 6 km SSW Eminiminy, Rés. Andohahela, 330 m (Ward, P. S.); 9 km SSW Eminiminy, Rés. Andohahela, 500 m (Ward, P. S.); Forêt Ivohibe, 200 m (Fisher, В. L.; et al.); Fort Dauphin (eu.); Grand Lavasoa, 450 m (Fisher, В. L.; et al.); P.N. Andohahela, Manampanihy, 5.4 km 113° ESE Mahamavo, 650 m (Fisher, В. L.; et al.); PN Andohahela, 275 m (Fisher, B. L.; et al).

Worker measurements (n = 11). HW

1.02-1.27, HL 1.05-1.42, LHT 1.05-1.38, CI 0.88-0.97, FCI 0.12-0.15, REL 0.31-0.36, REL2 0.35-0.39, SI 0.72-0.76, FI 0.29-0.31, PLI 0.50-0.55, PWI 0.43-0.53.

Worker diagnosis. Similar to T. grandidieri  HNS  (q.v.). Basal margin of mandible lacking tooth; anterior clypeal margin broadly convex and crenulate, directed forward; head relatively broad (CI 0.88- 0.97); metanotal spiracle not visible in lateral view of mesosoma (Fig. 5), subtended laterally and anterolaterally by a pair of concavities that are separated by a transverse carina; dorsal face of propodeum broadly convex in posterior view; standing pilosity and appressed pubescence generally sparse; integument mostly sublucid, with fine coriarious/puncticulate sculpture; head and mesosoma reddish-brown, upper part of propodeum often a darker red than rest of mesosoma; metasoma and appendages paler.

Comments. The worker of this species can be recognized by the absence of a tooth on the basal margin of the mandible; the more or less concolorous reddish-brown body (the upper half of propodeum is often a richer dark red, and the metasoma is paler); and the lack of a protruding metanotal spiracle when the mesosoma is viewed in profile (Fig. 5). In addition, the head tends to be broader than that of T. grandidieri  HNS  and Г. hespera  HNS  (CI 0.88-0.97, versus 0.77-0.88 in T. grandidieri  HNS  and 0.78- 0.90 in T. hespera  HNS  ). From T. hespera  HNS  it can also be distinguished by the ratio of metatibial length to head width (LHT/HW 1.02-1.09 in T. inermis  HNS  , and 1.10-1.22 in T. hespera  HNS  ).

In earlier identifications of muséum material I assigned the code name Tetraponera  HNS  psw81 to this species. During initial examination of Tetraponera hirsuta  HNS  I misidentified it as T. inermis  HNS  , using the code name Tetraponera  HNS  psw81. This is thebasis for the record of " Tetraponera  HNS  psw081" from Manongarivo (Fisher 2002: 318). In fact, T. inermis  HNS  is not known from that region.

In the Forel collection ( MHNG, Geneva) there is a problema tic worker from " Nosibé, village de lTmerina" [=Anosibe an'Ala at 19°26'S 48C13'E] (leg. Sikora). This worker is large (HW 1.49, LHT 1.79) and unicolored, with an elongate head (CI 0.78), yet the metanotal spiracles are not protruding in lateral view. This individuai combines features of T. inermis  HNS  and T. grandidieri  HNS  (unicolored form). At the moment I am unable to identify it with certainty.

Distribution and biology. T. inermis  HNS  occurs in eastern Madagascar from Montagne d'Anjanaharibe to the vicinity of Tolagnaro (Fort Dauphin) (Fig. 25). Collections all come from rainforest, at élévations ranging from 30 m to 1040 m. Nests are located in rotten sticks on the ground, and are small in size. At the type locality I found one dealate queen gleaning the surfaces of leaves, walking rapidly and raising her gaster in the air. She then returned to her nest -a cavity in a small soft dead twig on the ground -which proved to contain eggs, larvae and worker pupae. Thus, this species exhibits non-claustral colony-founding, a trait presumably shared with other members of the T. grandidieri  HNS  group. The gasterraising behavior was observed in foraging workers of T. inermis  HNS  but not those of the other two species with which T. inermis  HNS  is sympatric: T. grandidieri  HNS  and T. merita  HNS  . Camponotus reaumuri Forel  HNS  (related to C. putatus Forel  HNS  ) is a possible mimic of T. inermis  HNS  .


USA, California, San Francisco, California Academy of Sciences


United Kingdom, London, The Natural History Museum [formerly British Museum (Natural History)]


USA, Massachusetts, Cambridge, Harvard University, Museum of Comparative Zoology




South Africa, Cape Town, Iziko Museum of Capetown (formerly South African Museum)


USA, California, Davis, University of California, R.M. Bohart Museum of Entomology


USA, New York, Ithaca, Cornell University




Switzerland, Geneva, Museum d'Histoire Naturelle