Proceratium malesianum

Identification
A member of the itoi clade. Sister species of Proceratium bhutanense with which it shares synapoanorphically the palp formula 3,2 and the presence of a propodeal lamella. The two species are easily distinguished by the erect hairs present in malesianum and absent in bhutanense. (Baroni Urbani and de Andrade 2003)

Distribution
Malaysia: Pahang.

This taxon was described from West Malaysia.

Nomenclature

 *  malesianum. Proceratium malesianum De Andrade, in Baroni Urbani & De Andrade, 2003b: 275, fig. 115 (w.) WEST MALAYSIA.

Worker
Head longer than broad, its sides subparallel. Vertex in full face gently convex. Clypeus medially reduced, triangular, between and slightly longer than the antennal sockets. Clypeal dorsum with longitudinal carina. Antenna1 socket with broad torulus. Frontal carinae slightly far from each other, partially covering the antennal insertions. Frontal area behind the frontal carinae convex. Lateral expansions of the frontal carinae relatively narrow, raised, and diverging. Genal carinae marked. Eyes small, reduced to a dark dot below the integument, placed on the midline of the head. First funicular joint subeq~lalin size. Funicular joints 2-10 much broader than long. Last funicular joint about as long as the sum of joints 6-10. Scapes much short of the vertexal margin and gently thickening apically. Masticatory margin of the mandibles with 3 denticles before the pointed apical tooth. Palp formula 3,2.

Mesosoma slightly longer than the maximum head length (mandibles included). Promesopleural and meso-metapleural sutures impressed ventrally only. Basal face of the propodeum weakly declivous. Declivous face of the propodeum gently concave anteriorly. Basal and declivous faces of the propodeum separate laterally by a weakly carinate angle. Sides of the declivous face ofthe propodeum with a broad lamella. Propodeal spiracle round and placed above mid height in lateral view.

Petiole strongly convex in profile, with the sides diverging and strongly convex posteriorly in dorsal view. Anterior border of the petiole deeply concave and carinate, the carina strongly denticulate on each side. Ventral process of the petiole with 2-4 small, triangular denticles. Postpetiole anteriorly broader than the petiole; its sides diverging and gently convex posteriorly. Postpeliolar sternite anteromedially with a marked subtriangular projection. Postpetiolar sternite straight in profile. Constriction between postpetiole and first gastral segment impressed. Gastral tergite I strongly convex on the curvature. Remaining gastral tergites and sternites curved ventrally.

Legs slender but 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 113 shorter than hind tibiae. Second tarsomere of hind legs subequal to the fourth. Pretarsal claws simple. Arolia present.

Sculpture. Head, mesosoma, petiole and postpetiole granulate. First gastral tergite smooth and covered by piligeroirs punctures; its sides and the posterior border with additional granulation. Legs granulate, the granules less marked than in the other body parts.

Body covered by hairs of three main types: (1) short, dense, subdecumbent on the whole body, sparse and suberect on the funicular joints; (2) longer than type (I), sparse and s~tberecot n the whole body, slightly shorter on the scapes, absent on the funiculi; (3) shorter than hair type (I), dense and decumbent on the funicular joints only. In addition the funicular joints bear whitish, thick, appressed, short, sparse hairs.

Colour. Dark brown.

Measurements in mm and Indices: TL 2.57-3.24; HL 0.61-0.75; HW 0.53-0.65; EL 0.03-0.04; SL 0.36-0.45; WL 0.71-0.90; PeL 0.26-0.32; PeW 0.24-0.29; HFeL 0.43-0.55; MTiL 0.35-0.49; HBaL 0.21-0.31; LS4 0.20- 0.27; LT4 0.57-0.72; CI 87.0; SI 59.0-60.0; IGR 0.35-0.38.

Type Material
Holotype worker from West Malaysia labelled: "W. Malaysia. Pahang, Ringlet. 1250 m, ravine # 20, Lob1 & Calame, 26.3.93", in

Etymology
"malesianum" is a neologism indicating the provenance of this species from Malaysia.