Tetramorium setigerum

A common, ground-dwelling species. Tetramorium setigerum occurs in open to semi-open habitats, e.g., grassland, savanna, thornveld, and bushveld. Many collections of this species are from pitfall-trap and litter samples. There are no records with nest information.

Identification
Bolton (1980) - Tetramorium setigerum is the central species of the largest complex included in this group (as discussed under the species-group). The closest related species within the complex are Tetramorium agile and Tetramorium laevithorax, but the first of these has the mandibles without striate sculpture and the second has the promesonotal dorsum wholly or mostly smooth. The somewhat more distantly related Tetramorium avium and Tetramorium frenchi are smaller and more slenderly built species.

Distribution based on Regional Taxon Lists
Afrotropical Region: Democratic Republic of Congo, Gabon, Kenya, Mozambique, South Africa, Sudan, Uganda, United Republic of Tanzania, Zimbabwe.

Nomenclature

 *  setigerum. Tetramorium setigerum Mayr, 1901b: 22 (w.) SOUTH AFRICA. Forel, 1910e: 424 (q.m.). Senior synonym of anteversa, quaerens: Bolton, 1980: 283.
 * quaerens. Tetramorium setigerum r. quaerens Forel, 1914d: 226 (w.) ZIMBABWE. Junior synonym of setigerum: Bolton, 1980: 283.
 * anteversa. Tetramorium setigerum var. anteversa Santschi, 1921c: 121 (w.) TANZANIA. Junior synonym of setigerum: Bolton, 1980: 283.

Worker
Bolton (1980) - TL 3:4-4-0, HL 0:84-0:90, HW 0:68-0:72, CI 77-83, SL 0-70-0-80, SI 103-113, PW 0:50-0:56, AL 0-98-1-12 (20 measured). Mandibles longitudinally striate. Anterior clypeal margin entire, without a median notch or impression. Frontal carinae strongly developed, running back almost to occipital margin and surmounted by a raised rim or flange. Frontal carinae roughly parallel, only feebly sinuate or somewhat convergent posteriorly, quite close together, their maximum separation being about 0-47-0-51 x HW. Antennal scrobes narrow and shallow but fairly distinct. Antennal scapes relatively long, SI > 100. Maximum diameter of eye 0:18-0:22, about 0-28-0-31 x HW. With alitrunk in profile the propodeal spines quite short, stout and straight, distinctly longer than the low, triangular metapleural lobes but shorter than the maximum diameter of the eye. In a few individuals the propodeal spine length may approach the maximum eye diameter. Petiole in profile with a high node, the length of the dorsum less than the height of the tergal portion. The anterior face nearly vertical, meeting the dorsal surface in a sharp right-angle. Behind this the dorsum slopes slightly downwards posteriorly to the blunt or rounded posterodorsal angle. In dorsal view the petiole node much broader than long, distinctly broader behind than in front. Dorsum of head irregularly and quite finely longitudinally rugulose, often with scattered cross-meshes behind the level of the eyes. Occipital area with more cross-meshes or with a weak reticulum present. Ground-sculpture of dorsal head a fine but fairly conspicuous punctulation or granulation between the rugulae. Dorsal alitrunk finely and densely rugulose, often (but not always) forming reticulations in places; the rugulose sculpture overlying a fine densely punctulate ground-sculpture. Dorsal surfaces of petiole and postpetiole finely rugulose with punctulate ground-sculpture. First gastral tergite either smooth basally or with a band of fine shagreening of variable development. All dorsal surfaces of head and body with numerous strong standing hairs but tibiae of middle and hind legs only with fine, short, decumbent to appressed pubescence. Colour uniform mid to dark brown, usually with the gaster darker in shade than the head and alitrunk.

Type Material
Bolton (1980):

Syntype workers: Syntype workers, SOUTH AFRICA: Bothaville (H. Brauns) [examined].

Syntype workers, RHODESIA: Bulawayo 1.xii.1912 (G. Arnold) [examined].

Tetramorium setigerum var. anteversa. Holotype worker, TANZANIA: Bukoba (Viehmeyer) (type not found, presumed lost).

References based on Global Ant Biodiversity Informatics

 * Arnold G. 1917. A monograph of the Formicidae of South Africa. Part III. Myrmicinae. Annals of the South African Museum. 14: 271-402.
 * 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.
 * Forel A. 1910. Note sur quelques fourmis d'Afrique. Annales de la Société Entomologique de Belgique 54: 421-458.
 * 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
 * Kotze D. J., and M. J. Samways. 2001. No general edge effects for invertebrates at Afromontane forest/grassland ecotones. Biodiversity and Conservation 10: 443466.
 * Lindsey P. A., and J. D. Skinner. 2001. Ant composition and activity patterns as determined by pitfall trapping and other methods in three habitats in the semi-arid Karoo. Journal of Arid Environments 48: 551-568.
 * Samways M. J. 1990. Species temporal variability: epigaeic ant assemblages and management for abundance and scarcity. Oecologia 84: 482-490.
 * 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