Tetramorium warreni

A species of open to semi-open habitats, T. warreni has been collected from grassland, open woodland, and shrubland.

Identification
Bolton (1980) - Like the closely related Tetramorium typhlops, T. warreni is distinguished from its closest relatives by its small size, single-faceted eyes, complete lack of frontal carinae and antennal scrobes, and vestigial sculpture. Characters useful in separating T. warreni and T. typhlops are discussed under the latter name.

Distribution based on Regional Taxon Lists
Afrotropical Region: South Africa.

Nomenclature

 *  warreni. Tetramorium warreni Arnold, 1926: 268, fig. 75 (w.) SOUTH AFRICA. See also: Bolton, 1980: 294.

Worker
Bolton (1980) - TL 2.1-2.3, HL 0.52-0.53, HW 0.44-0.45, CI 84-85, SL 0.30-0.33, SI 68-71, PW 0.30-0.32, AL 0.56-0.58 (2 measured).

Mandibles longitudinally striate. Anterior clypeal margin with a minute median indentation on the apron, difficult to see when mandibles are fully closed. Median carina faint but running the length of the clypeus. Lateral portions of clypeus strongly developed into a raised shield on each side in front of the antennal insertions (see discussion under Tetramorium typhlops). Frontal carinae absent, the posteriormost part of the frontal lobes curving outwards around the rim of the antennal fossa for a short distance. Antennal scrobes absent, the dorsum of the head rounding smoothly into the sides. Eyes minute, of a single ommatidium, the maximum diameter approximately 0:03, about 0:07 x HW. Minute species with HW < 0-50, the antennal scapes both absolutely and relatively short, SL < 0-35, SI < 75. Propodeum in profile armed with a pair of short triangular teeth which are about the same length or slightly shorter than the triangular metapleural lobes. Petiole in profile with a narrow node, the dorsal length less than the height of the tergal portion. Posterodorsal angle of node more rounded than the anterodorsal, which is roughly a blunt right-angle. Petiole node in dorsal view broader than long. Dorsum of head with faint, feeble and irregular longitudinal rugulae, with only the weakest vestiges of ground-sculpture between them. Dorsal surfaces of alitrunk, petiole, postpetiole and gaster unsculptured or the alitrunk with a few faint, poorly defined and exceptionally feeble vestiges of sculpture. All dorsal surfaces of head and body with short, fine, standing hairs, the dorsal (outer) surface of the hind tibiae with fine short pubescence. Colour uniform clear, pale yellow.

Type Material
Bolton (1980) - Syntype workers, SOUTH AFRICA: Natal, 15.x 1898 (Haviland) [examined].

References based on Global Ant Biodiversity Informatics

 * Arnold G. 1926. A monograph of the Formicidae of South Africa. Appendix. Annals of the South African Museum. 23: 191-295.