Tetramorium basum

Nothing is known about the biology of .

Identification
Bolton (1977) - In the ornatum-group two species are presently known in which the spaces between the carinate cephalic sculpture are filled with dense puncturation. T. basum is one of these, the other being Tetramorium rigidum. The two are separable as in rigidum there are a number of conspicuous cross-meshes between the longitudinal carinae of the head, absent in basum, and the gaster is uniformly coloured in rigidum, without the basal yellow area seen in basum.

Distribution based on Regional Taxon Lists
Indo-Australian Region: New Guinea.

Nomenclature

 *  basum. Tetramorium basum Bolton, 1977: 104, fig. 30 (w.) NEW GUINEA.

Worker
Holotype. TL 3.2, HL 0.74, HW 0.66, CI 89, SL 0.56, SI 85, PW 0.48, AL 0.90.

Mandibles striate, anterior clypeal margin convex and entire. Frontal carinae extending back beyond the posterior margin of the eyes but then broken or interrupted, their place taken by the coarse longitudinal sculpture which is as strongly developed as the frontal carinae and which extends back to the occipital margin. Maximum diameter of eye c. 0.14. Occipital margin of head broadly but shallowly concave in full-face view, the sides of the head only very feebly convex. Propodeal spines very long, narrow and acute, elevated and downcurved along their length. Metapleural lobes broad basally but quickly narrowing to an elongate acute point. Petiole in profile with a long, downcurved anterior peduncle, shape of the node as shown in Fig. 30. Clypeus with five main longitudinal carinae and with other shorter, weaker carinae present. Dorsum of head densely sculptured with regular coarse longitudinal carinae without cross-meshes of any sort, the spaces between the carinae filled with a dense and very conspicuous reticulate-puncturation. Dorsal alitrunk with a rugoreticulum, the meshes small and the spaces which they enclose with some puncturation which is much weaker than that seen on the head. Petiole with longitudinal rugae which are oblique and spaced out on the sides but more close-packed dorsally. Postpetiole and gaster unsculptured, smooth and shining. Fine hairs present on all dorsal surfaces of head and body. Dorsal (outer) surfaces of hind tibiae with short subdecumbent or decumbent hairs which are much shorter than the maximum tibial width. Colour reddish brown, the appendages yellow or yellow-brown. First gastral tergite with the basal third yellow, the remainder blackish brown.

Paratype. As holotype but slightly smaller, TL 2.9, HL 0.70, HW 0.64, CI 91, SL 0.52, SI 81, PW 0.46, AL 0.84.

Type Material
Holotype worker, New Guinea: Mongi Watershed, Huon Pen., Wamuki, 19-20.iv.1955, 800 m, no. 846 (E. O. Wilson). Paratype. 1 worker with same data as holotype.