Cataulacus regularis

Cataulacus regularis is found in a variety of forest habitats in Madagascar.

Identification
The sculpturation seen in Cataulacus regularis is very uncommon, being met with only in one other Madagascan species, the seemingly closely related Cataulacus porcatus. This latter species is, however, smaller and has some erect hairs on the dorsal alitrunk, besides differences in sculpturation, In species of other groups in which at least the alitrunk is longitudinally sulcate there are other marked differences, most obvious amongst which are presence of hairs or denticles or both upon the alitrunk, and marked differences in the shape of this portion of the body.

Distribution
This taxon was described, and is only known, from Madagascar.

Nomenclature

 *  regularis. Cataulacus regularis Forel, 1892l: 252 (w.) MADAGASCAR. See also: Bolton, 1974a: 27.

Worker
Bolton (1974) - TL 5.3 – 5.9, HL 1.22 – 1.32, HW 1.30 – 1.32, CI 100 – 107, EL 0.42 – 0.46, OI 32 - 35, IOD 1.04 – 1.06, SL 0.68 – 0.72, SI 52 - 54, PW 1.10 – 1.18, AL ca 1.68, MTL 0.66 – 0.70 (2 measured).

Lateral portions of occipital crest developed, unarmed. Medially the crest is very poorly developed, concave or broadly V-shaped in full-face view. Sides of head behind eyes smooth, not denticulate. Occipital corners irregular or with one or two obtuse, low prominences, not armed with teeth or spines. Sides of alitrunk without denticles. Humeral angles acute, separated by a short but marked concavity from the beginnings of the pronotal margination; the latter joining the mesonotum at a slight notch. Promesonotal suture visible as an impression across the sculpturation but not breaking it. Mesonotal margination ending in a triangular, dentiform process posteriorly, in front of a distinct notch separating mesonotum from propodeum, Propodeal marginations strongly convex anteriorly, converging behind to a pair of short, narrow, virtually parallel spines. Petiole longer than broad in dorsal view, with a small but distinct laterally projecting tooth at about the mid length on either side. In profile the petiole somewhat flattened, with a steep anterior face and a long, somewhat sloping dorsal face; without a differentiated free posterior surface before the junction with the postpetiole. Subpetiolar process complex, with a tooth posteroventrally. Anterior subpostpetiolar process variable in size but simple. Sides of postpetiole in dorsal view with one or two denticles. Gaster not marginate laterally.

Dorsal surfaces of head behind clypeus, alitrunk, petiole and postpetiole strongly sculptured with regular, parallel longitudinal sulci, the spaces between the sulci broadly convex and giving the cuticle a ploughed appearance. The pronotal sulci are slightly wavy in the larger specimen examined, much more regularly organized in the smaller. First gastral tergite finely reticulate-punctate with a few scattered, fine, longitudinal rugulae. Clypeus sculptured much as rest of head but more finely so, and with a tendency for the sulci to fade out anteriorly.

Dorsal surfaces of head and alitrunk and margins of alitrunk without hairs. Short hairs are present upon the petiole, postpetiole, apex of first gastral tergite and margins of frontal carinae; appendages with numerous short, erect hairs.

Type Material
Bolton (1974) - Syntype workers, Madagascar: Bezanozano, Anosibe (Sikora) (MHN, Geneva) [examined].