Tetramorium regulare

Identification
Bolton (1980) - This yellowish brown species is closely related to Tetramorium grassii but differs from it by having stout, blunt pilosity rather than the long, acute hairs seen in T. grassii. The cephalic sculpture is more sharply defined and much more regular in T. regulare, and the clypeal notch, generally distinct in T. grassii, is here vestigial or absent.

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

Nomenclature

 *  regulare. Tetramorium regulare Bolton, 1980: 263, fig. 45 (w.m.) SOUTH AFRICA.

Worker
Holotype: TL 3.5, HL 0.79, HW 0.71, CI 90, SL 0.57, SI 80, PW 0.52, AL 0.92. Paratypes (20 measured): TL 3.0-3.6, HL 0.70-0.80, HW 0.64-0.72, CI 89-92, SL 0.52-0.58, SI 77-82, PW 0.46-0.53, AL 0.82-0.94. Maximum diameter of eye 0.16-0.18, about 0.24-0.26 x HW.

Mandibles longitudinally striate. Anterior clypeal margin entire, without a median impression but the margin centrally somewhat flattened. (In some paratypes an exceptionally feeble impression is visible.) Frontal carinae extending back almost to occiput, sharply defined and surmounted by a narrow raised rim or flange which is highest at the level of the eyes and becomes lower posterior to this, but is always more strongly defined than the remaining cephalic sculpture. Antennal scrobes present. Eyes moderate, maximum diameter 0.18, about 0.25 x HW. With the alitrunk in profile the metanotal groove very shallowly impressed, the propodeal dorsum sloping to a pair of long, stout spines. Metapleural lobes long triangular, acute apically and slightly upcurved along their length. Peduncle of petiole with a narrow sagittal crest ventrally. Node of petiole high and narrow, the tergal portion much higher than the dorsal length. In profile the anterodorsal angle more sharply rounded and on a slightly higher level than the posterodorsal, so that the dorsum slopes downwards behind to the very broadly rounded posterodorsal angle. In dorsal view both nodes broader than long. Clypeus with three longitudinal carinae, the median the strongest. Dorsum of head with regular, spaced, sharply defined carina-like rugulae which run uninterruptedly from clypeus to occiput without cross-meshes or anastomoses anywhere. 10-12 such carinate rugulae present between the frontal carinae at the level of the eyes. Spaces between the longitudinal components smooth, with only vestiges of ground-sculpture. Dorsal alitrunk less strongly and less regularly rugulose, with occasional cross-meshes, especially on the pronotum. Petiole, postpetiole and gaster unsculptured. All dorsal surfaces of head and body with numerous erect or suberect long stout hairs which are blunt apically. Scapes and tibiae with fine short pubescence, decumbent to appressed. Colour uniform yellowish brown.

Paratypes: As holotype but in some the clypeus with a further pair of carinae, much weaker than the principal three and usually incomplete. The anterior clypeal margin varies from entire and convex, through a majority of individuals in which the margin is flattened medially to a minority in which a feeble median impression can be seen.

Type Material
Holotype worker, South Africa: Cape Prov., Grahamstown, Signal Hill, 10.ii.1969, under rock, pine-native scrub (W. L. Brown). Paratypes. 4 workers with same data as holotype; 11 workers with same data but collected 20.ii.69, series M82; 5 workers and 4 males with same data but collected 18.ii.69, series M79 (L. Weatherill & W. L. Brown) (MCZ; ; ).

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.