Taxonomic History (provided by Barry Bolton, 2013)
occurs in eastern Madagascar from Montagne d'Anjanaharibe to the vicinity of Tolagnaro (Fort Dauphin). Collections all come from rainforest, at elevations ranging from 30 m to 1040 m.
is apparently confined to rainforest. Nests are located in rotten sticks on the ground, and are small in size. At the type locality (1 km SSW Andasibe) a dealate queen was observed 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 (Ward, 2009). Thus, this species exhibits non-claustral colony-founding, a trait presumably shared with other members of the T. grandidieri group. The gaster-raising behavior was observed in foraging workers of T. inermis but not those of the other two species with which T. inermis is sympatric: T. grandidieri and T. merita. Camponotus reaumuri Forel (related to C. putatus Forel) is a possible mimic of T. inermis.
Within the grandidieri
group this species is recognized by a combination of the following worker features:
- basal margin of mandible lacking tooth; masticatory margin with four teeth
- petiole slender, obovate, with an elongate anterior peduncle
- metanotal spiracle not protruding above the profile of the mesosoma, as seen in lateral view
- head broad (CI 0.88-0.97)
- head and mesosoma reddish-brown, metasoma and appendages paler
The worker of T. inermis
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. In addition, the head tends to be broader than that of T. grandidieri
and T. hespera
(CI 0.88-0.97, versus 0.77-0.88 in T. grandidieri
and 0.78-0.90 in T. hespera). From T. hespera it can also be distinguished by the ratio of metatibial length to head width (LHT/HW 1.02-1.09 in T. inermis, and 1.10-1.22 in T. hespera).
Ward, P. S. 2009. The ant genus Tetraponera
in the Afrotropical region: the T. grandidieri
group (Hymenoptera: Formicidae). Journal of Hymenoptera Research 18: 285-304.
Taxon Page Author History
Specimen Data Summary
Found most commonly in these habitats: 26 times found in rainforest, 2 times found in rainforest, transition to montane forest
Collected most commonly using these methods or in the following microhabitats: 4 times MW 50 sample transect, 5m, 2 times beating low vegetation, 2 times 9 Maxi winklers, 1 times Malaise trap, 1 times pitfall trap, PF 50 sample transect, 5m
Elevations: collected from 30 - 920 meters, 473 meters average