Proceratium burundense

The only species of the genus with workers that have compound eyes.

Identification
A member of the arnoldi clade. Differing from its sister species, Proceratium lunatum, in the worker, by the head more elongate and the scape longer and less robust, by the smaller and more superficial foveae over the whole integument and by the subtler sculpture on the gaster. (Baroni Urbani and de Andrade 2003)

Key to Afrotropical Proceratium Species

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

Nomenclature

 *  burundense. Proceratium burundense De Andrade, in Baroni Urbani & De Andrade, 2003b: 294, fig. 122 (w.) BURUNDI.

Worker
Head slightly longer than broad, its sides weakly convex. Vertex in fill1 face view slightly convex, in full dorsal view flat and bearing on each side a round, semitransparent macula. Clypeus medially reduced, subconvex, between the and slightly longer than the antennal sockets. Anterior border of the clypeus minutely crenulate. Antennal socket with broad torulus. Frontal carinae far from each other, partially covering the antennal insertions. Frontal area concave posteriorly, the concavity connected to a longitudinal carina prolonging posteriorly. Lateral expansions of the frontal carinae broader than in lunatum, slightly raised, diverging on the two anterior thirds and slightly converging on the posterior third. Genal carinae marked, each carina corresponding to the external border of a deep sulcus. Eyes relatively large, composed by 9 ommatidia and placed on the midline of the head. First funicular joint slightly longer than broad. Funicular joints 2-10 broader than long. Last funicular joint about as long as the sum of joints 7-10. Scapes much shorter than the vertexal margin and gently thickening apically. External border of the mandibles concave. Masticatory margin of the mandibles with 3-4 denticles before the pointed apical tooth. Palp formula 3,2.

Mesosoma convex in profile and slightly longer than the maximum head length (mandibles included). Basal face of the propodeum gently declivous posteriorly. Area between the basal and declivous faces of the propodeum weakly concave. Basal and declivous faces of the propodeum separate laterally by a lamellaceous tooth. Sides of the declivous face of the propodeum with a broader and posteriorly obtuse lamella. Lower mesopleurae with well defined sutures, their posterior half strongly inflate and smooth. Propodeal spiracle round and above mid height in lateral view.

Petiolar node subconvex in profile, the dorsum of the node almost flat and bearing an irregular point postero-medially. Petiole in dorsal view with the sides diverging on the anterior fifth and convex posteriorly; its anterior border almost straight, carinate and laterally denticulate. Ventral process of the petiole lamelliform, subrectangular, the lamella strongly pointed posteriorly. Postpetiole anteriorly broader than the petiole; its sides gently convex. Postpetiolar dorsum with a postero-medial, semitransparent, flat bulla below the integument. Postpetiolar sternite anteromedially with a marked subtriangular projection. Postpetiolar stenlite strongly convex posteriorly in profile. Constriction between postpetiole and gaster impressed. Gastral tergite I convex on the curvature and with a postero-medial, semitransparent, flat bulla below the integument. Remaining gastral tergites and sternites curved ventrally.

Legs slender and more elongate than in lunatunz. 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. First tarsomere of hind legs subequal in size to the pretarsus. Pretarsal claws simple. Arolia present.

Sculpture. Head, mesosoma, petiole, postpetiole and gaster with small, irregular Foveae and granulate, the foveae smaller, shallower and sparser on the anterior third of the first gastral tergite. Caster with additional longitudinal, irregular, thin rugosities on the posterior two thirds. Legs punctate. Pilosity similar to lunatum but the hair type (1) suberect and subdecumbent and type (2) sparser.

Colour. Light fesrugineous-brown with lighter legs.

Measurernents in mrn and Indices: TL 3.44; HL 0.79; HW 0.72; EL 0.06; SL 0.54; WL 1.02; PeL 0.33; PeL 0.33; PeW 0.38; HFeL 0.59; HTiL 0.51; HBaL 0.39; LS4 0.24; LT4 0.61; CI 91.1; S168.3; IGR 0.39.

Type Material
Holotype worker (unique) from Burundi labelled: "Burundi, Bujumbura, 4.III.77, A. Dejean" in.

Etymology
"Burundense" is a neologism indicating the provenance from Burundi.