Proceratium terraealtae

The holotype was collected in the Cameron highlands.

Identification
A member of the silaceum clade, resembling Proceratium caledonicum, but differing from it in the worker, by the broader frontal carinae and by the SI > 70 instead of < 65. Proceratium terraealtae, for its smooth mesosoma and gaster, is apparently similar to two geographically distant species, i.e. Proceratium caledonicum and Proceratium politum, both from New Caledonia. It can be easily distinguished from both, among other characters, by the head more sculptured and by the denticulate sides of the propodeum. (Baroni Urbani and de Andrade 2003)

Key to Indomalayan Proceratium Species

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

Nomenclature

 *  terraealtae. Proceratium terraealtae De Andrade, in Baroni Urbani & De Andrade, 2003b: 330, fig. 133 (w.) WEST MALAYSIA.

Worker
Head slightly longer than broad and with the sides gently diverging posteriorly. Vertex in full face view weakly convex. Clypeus reduced and as long as the antennal sockets. Anterior border of the clypeus truncate. Frontal carinae broad and not covering the antennal insertions. Lateral expansions of the frontal carinae narrow, little raised, diverging on the two anterior fourths, converging on the third fourth, diverging and carinate only on the posterior fourth. Frontal area gently concave and with a marked longitudinal carina prolonging posteriorly. Head anterolaterally with a short, longitudinal carina. Genal carinae marked, each carina corresponding to the external border of a deep sulcus. Eyes visible as a dark dot below the integument, small and on the middle of the head sides. First funicular joint slightly broader than long. Funicular joints 2-10 broader than long. Last funicular joint as long as the sum of joints 6-10. Scapes short of the vertexal margin and gently thickening apically. Masticatory margin of the mandibles with 8 denticles before the pointed apical tooth. Palp formula 2,2.

Mesosoma weakly convex in profile, shorter than maximum head length (mandibles included). Protlotal and propodeal sutures absent. Basal face of the propodeum declivous posteriorly. Area between basal and declivous faces of the propodeum weakly concave and denticulate on each side. Declivous face of the propodeum sloping posteriorly. Sides of the declivous face of the propodeum weakly marginate. Propodeal spiracle round and above mid height in lateral view.

Petiole subrectangular and not very thick, its anterior border straight and anterolaterally carinate. Ventral process of the petiole large, triangular and curved posteriorly. Postpetiole less than 1/3 shorter than gastral tergite I, with the anterior half diverging and the posterior half gently convex in dorsal view. Postpetiolar sternite anteromedially with a marked subtriangular projection and gently convex posteriorly in profile. Constriction between postpetiole and gaster impressed. Gastral tergite 1 convex on the curvature. Remaining gastral tergites and sternites curved ventrally.

Legs not very elongate. All tibiae with a pectinate spur. Spurs of fore legs without basal spine. Fore basitarsi longer than the mid ones. Hind basitarsi about 1/4 shorter than hind tibiae. Second tarsomere of hind legs shorter than pretarsus. Pretarsal claws simple. Arolia absent.

Sculpture. Body largely shining. Head densely punctate and with sparse, thin, irregular rugosities. Area below the eyes and ventral part of the head reticulorugose. Mesosoma, petiole, postpetiole, gaster and legs minutely punctate.

Body covered by hairs of three main types: (1) short, dense, suberect or subdecumbent on the whole body, sparse on the funicular joints; (2) longer than type (1), erect on the whole body, absent on the antennae; (3) shorter than hair type (1), dense and decumbent on the funicular joints only. In addition the funicular joints bear whitish, thick, appressed, sparse hairs, and the scapes with sparse hairs similar to type (2) but shorter.

Colour. Light brown with lighter legs.

Measurements in mm and Indices: TL 2.72-2.86; HL 0.65-0.67; HW 0.62-0.65; EL 0.03-0.04; SL 0.46-0.48; WL 0.76-0.80; PeL 0.18-0.19; PeW 0.27-0.28; HFeL 0.48-0.49; HTiL 0.41 -0.43; HBaL 0.31-0.32; LS4 0.30-0.33; LT4 0.59-0.62; CI 95.4-97.0; SI 70.7-71.6; IGR 0.51-0.53.

Type Material
Holotype worker labeled: "W-Malaysia, Pahang, Cameron Hlnds., XI.1987, Wheatcroft", in.

Etymology
From the Latin "terra alta", a literal translation of highlands, referred to the Cameron Highlands, the mountains of Malaysia where the species was collected.