Tetramorium altivagans

An upland or mountain species of southern and eastern Africa.

Identification
A member of the Tetramorium simillimum species group.

Bolton (1980) - Tetramorium altivagans is distinguished from other members of the poweri-complex by its dark colour, size and relatively long scapes. Within the complex it is closest related to Tetramorium pusillum and Tetramorium nigrum. The first of these is easily separated by its possession of smooth mandibles, but the separation of nigrum rests on the relative development of the propodeal teeth and this may not be a good character as some variation is visible in the altivagans material presently available.

Distribution based on Regional Taxon Lists
Afrotropical Region: Kenya, Sudan, United Republic of Tanzania.

Nomenclature

 *  altivagans. Tetramorium caespitum st. altivagans Santschi, 1914b: 103 (w.) KENYA. Subspecies of pusillum: Emery, 1924d: 281. Raised to species and senior synonym of isis: Bolton, 1980: 305.
 * isis. Tetramorium simillimum subsp. isis Weber, 1943c: 373 (w.) SUDAN. Junior synonym of altivagans: Bolton, 1980: 305.

Worker
Bolton (1980) - TL 2.6-2.7, HL 0.60-0.64, HW 0.52-0.56, CI 84-88, SL 0.44-0.50, SI 84-91, PW 0.36-0.40, AL 0.68-0.72 (10 measured).

Mandibles longitudinally striate, usually coarsely and conspicuously so, less commonly with the striation finer but always distinct. Anterior clypeal margin entire, without trace of a median notch. Frontal carinae present but only weakly developed, no more strongly defined than the dorsal cephalic rugulae; always running back beyond the level of the eyes and generally approaching the occiput. In many the carinae are broken or interrupted along their length or their margins are irregular, and in some the real frontal carinae end abruptly and their function is taken over by one or more of the cephalic rugulae which curve out to replace the carina. Antennal scrobes vestigial, at most merely a feeble impression in the side of the head below the frontal carina. Maximum diameter of eye 0.12-0.14, about 0.24-0.25 x HW and with 7-9 ommatidia in the longest row. Propodeum armed with a pair of short triangular teeth which at most are as long as the metapleural lobes but are usually shorter. Petiole node in dorsal view broader than long. Dorsum of head finely and quite densely longitudinally rugulose, the ground-sculpture feeble and consisting only of light shagreening or very weak superficial punctulation, the surface glossy. Dorsal alitrunk finely and densely punctulate, this sculpture more strongly developed than on head, and usually with numerous fine rugulae. Petiole and postpetiole superficially punctulate, commonly one or both segments with vestigial rugular traces. First gastral tergite unsculptured or with a narrow band of fine shagreening basally. All dorsal surfaces of head and body with numerous short, stout blunt hairs. Colour dark brown to blackish brown.

Type Material
Bolton (1980) - Syntype workers, Kenya: Mt Kinangop, chaine de I’Aberdare, 3100 m, st. no. 55, ii.1912 (Alluaud & Jeannel) [examined]. Tetramorium simillimum subsp. isis Weber, 1943: 373. Syntype workers, SUDAN: Imatong Mts, 8700 ft [2650 m], 28.vii.1939, no. 1350 (N. A. Weber) [examined].

References based on Global Ant Biodiversity Informatics

 * Bolton B. 1980. The ant tribe Tetramoriini (Hymenoptera: Formicidae). The genus Tetramorium Mayr in the Ethiopian zoogeographical region. Bulletin of the British Museum (Natural History). Entomology 40: 193-384.
 * Garcia F.H., Wiesel E. and Fischer G. 2013.The Ants of Kenya (Hymenoptera: Formicidae)Faunal Overview, First Species Checklist, Bibliography, Accounts for All Genera, and Discussion on Taxonomy and Zoogeography. Journal of East African Natural History, 101(2): 127-222
 * IZIKO South Africa Museum Collection
 * Weber N. A. 1943. The ants of the Imatong Mountains, Anglo-Egyptian Sudan. Bulletin of the Museum of Comparative Zoology 93: 263-389.
 * Wheeler W. M. 1922. Ants of the American Museum Congo expedition. A contribution to the myrmecology of Africa. VIII. A synonymic list of the ants of the Ethiopian region. Bulletin of the American Museum of Natural History 45: 711-1004