Proceratium cubanum

Identification
A member of the micrommatum clade and resembling Proceratium poinari and Proceratium taino, in the worker, but differing from poinari by the lack of a clear propodeal carina, by the postpetiole anterolaterally round instead of angulate and by the mid basitarsi without hairs longer than 1/2 of the hind basitarsi; and from taino, in the worker, by the smaller size (TL ≤ 3.00 mm instead of ≥ 3.70 mm) and by the hairs of type 2 sparser.

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

Nomenclature

 *  cubanum. Proceratium cubanum De Andrade, in Baroni Urbani & De Andrade, 2003b: 194, fig. 83 (w.) CUBA.

Worker
Head longer than broad, slightly narrower anteriorly than posteriorly. Vertex in full face view weakly convex. Clypeus very reduced, triangular and slightly longer than the antennal sockets. Antennal socket with broad torulus. Frontal carinae close to each other, not covering the antennal insertions. Frontal area behind the frontal carinae weakly convex. Lateral expansions of the frontal carinae relatively narrow, raised and parallel. Genal carinae marked. A superficial sulcus between the genal carinae and the gular area. Eyes composed by a clearly convex facet and placed below the midline of the head. Scapes thicker in the distal half and short of the vertexal margin. First funicular joint 1/3 longer than broad. Funicular joints 2-10 broader than long. Last funicular joint as long as the sum of joints 6-10. Mandibles with 3 denticles before the apical tooth. Palp formula probably 3,2.

Mesosoma weakly convex in profile. Promesonotal and propodeal sutures absent. Promesopleural and mesometapleural sutures impressed on the ventral half only. Basal face of the propodeum gently declivous and with a superficial, transversal sulcus close to the declivous face; the sulcus poorly impressed and weakly marginate posteriorly. Declivous face of the propodeum with the sides superficially marginate, the margin more marked posteriorly. Propodeal lobes subround and with variably crenulate margin. Propodeal spiracles small and projecting.

Petiole about as long as broad, with the sides subparallel in the anterior fourth and convex posteriorly in dorsal view. Anterior border of the petiole slightly concave, carinate and angulate on each side. Ventral process of the petiole subtriangular and small. Postpetiole slightly shorter than 1/2 of the length of the gastral tergite I (LT4), anterolaterally convex in dorsal view. Postpetiolar sternite anteromedially with a superficially raised subtriangular projection. Posterior half of the postpetiolar sternite straight or slightly convex. Constriction between postpetiole and gastral segment I deeply impressed. Gastral tergite I convex on the curvature. Gastral sternite I very short medially. Sides of gastral sternite I not protruding, superficially carinate only. Remaining gastral tergites and sternites curved ventrally.

Mid tibiae without spur. Spurs of fore legs without basal spine. Fore basitarsi longer than the mid ones. Hind basitarsi about 1/5 shorter than hind tibiae. Second tarsomere of mid and hind legs longer than third and fourth tarsomeres, and slightly shorter than pretarsus. Pretarsal claws simple. Arolia very small.

Sculpture. Head, mesosoma, petiole and postpetiole granulopunctate, the granules more marked on the petiole and postpetiole. In addition, the head with thin, irregular rugosities. First gastral tergite smooth and with minute piligerous foveae; sides and posterior part of the first gastral tergite with larger piligerous punctures which are substituted by reticulation and granules close to the border. Legs variably granulate-punctate.

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

Colour light brown.

Measurements in mm and Indices: TL 2.96-3.00; HL 0.70; HW 0.62; EL 0.04-0.09; SL 0.44-0.45; WL 0.80-0.81; PeL 0.28; Pew 0.26-0.29; HTiL 0.43; HBaL 0.35-0.37; LS4 0.16; LT4 0.70-0.75; CI 88.6; SI 62.8-64.3; IGR 0.21 -0.23.

Type Material
Holotype worker from Cuba labelled "Holguin, Ote, II-1976, L. Armas bajo piedra", in.

Etymology
"Cubanum" is a neologism indicating the provenance of this species from Cuba.