Tetramorium tortuosum

A Sri Lanka specimen was found under a stone.

Identification
Bolton (1977) - This species is close to Tetramorium yerburyi and Tetramorium pilosum; its distinction from those species is discussed under yerburyi.

Distribution based on Regional Taxon Lists
Indo-Australian Region: Philippines. Oriental Region: India, Sri Lanka.

Nomenclature

 *  tortuosum. Tetramorium tortuosum Roger, 1863a: 181 (w.q.) SRI LANKA. Senior synonym of bellii, ethica: Bolton, 1977: 83.
 * bellii. Tetramorium (Xiphomyrmex) tortuosum var. bellii Forel, 1902c: 239 (w.) INDIA. Junior synonym of tortuosum: Bolton, 1977: 83.
 * ethica. Tetramorium (Xiphomyrmex) tortuosum var. ethica Forel, 1911i: 225 (w.) SRI LANKA. Junior synonym of tortuosum: Bolton, 1977: 83.

Worker
Bolton (1977) - TL 3.8-4.4, HL 0.82-0.92, HW 0.78-0.86, CI 89-95, SL 0.70-0.80, SI 89-97, PW 0.60-0.70, AL 1.12-1.20 (15 measured).

Mandibles striate. Antennal sea pes moderately long, with SI approaching 100 but apparently always with HW> SL. Frontal carinae long, reaching back almost or quite to the occipital margin, the latter broadly and very shallowly concave. Antennal scrobes shallow and feeble impressions, shorter than the scape and not capable of containing it. Pronotal corners in dorsal view with rounded angles. Propodeal spines strong and acute, the metapleural teeth acute and generally triangular, but narrow in some specimens. Node of petiole in profile longer than high, the dorsal surface feebly convex and meeting the anterior face in a blunt but distinct angle. Post petiole rounded, convex above. In dorsal view the petiole node slightly longer than broad, the postpetiole subglobular and somewhat broader than long. Dorsum of head firmly and predominantly longitudinally rugulose but with a tendency to form narrow and feeble cross-meshes, especially posteriorly. The rugulae themselves are narrow, low and rounded. Dorsal alitrunk with similar but even more feeble rugulation, in places the rugulae tending to be effaced and replaced by shining areas. Sides of petiole usually retaining faint traces of sculpture but the dorsum generally smooth, only rarely with vestiges of sculpture. Postpetiole and gaster unsculptured. Hairs on dorsal head and alitrunk variable in length, usually shorter and stouter in Sri Lankan populations than in examples from India.

Type Material
Bolton (1977) - Syntype worker, female, Sri Lanka (H. Nietner) (location of types not known).