Proceratium catio

Workers have been collected from the leaf litter of tropical rainforest.

Identification
A member of the micrommatum clade. catio is the sister species of Proceratium brasiliense (q. v.) but differs from it, in the worker and gyne, by the petiole 1/5 longer than broad instead of at most 1/8 longer than broad, by the postpetiole shorter than 1/2 of the length of the gastral tergite I (LT4) instead of slightly longer and by the postpetiole and gaster, both more convex than in brasiliense. (Baroni Urbani and de Andrade 2003)

Key to Nearctic and Neotropical Proceratium Species

Distribution
Known from Colombia, Ecuador and Venezuela.

Distribution based on Regional Taxon Lists
Neotropical Region: Colombia, Venezuela.

Nomenclature

 *  catio. Proceratium catio De Andrade, in Baroni Urbani & De Andrade, 2003b: 135, figs. 62 - 64 (w.) COLOMBIA.

Worker
Head longer than broad, with subparallel sides. Vertex in full face view convex. Clypeus corresponding to a small triangular tooth between the antennal socket. 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 diverging posteriorly. Genal carinae strongly marked. Sulcus between the genal carinae and the gular area impressed. Eyes composed by a clearly convex facet slightly below the midline of the head. Scapes thicker in the distal half and far 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 7-10. Mandibles with 5-6 denticles before the apical tooth. Palp formula 3,2.

Mesosoma slightly elongate. Promesopleural and mesometapleural sutures impressed on the ventral half only. Basal face of the propodeum with a high medial tumulus; area behind the propodeal tuinulus short, resembling a transversal sulcus with the postero-lateral border carinate. Declivous lace of the propodeum flat, the sides crenulate and sub-convex close to the propodeal lobes. Propodeal lobes truncate. Propodeal spiracles tumuliform.

Petiole longer than broad, subparallel in the anterior fourth and convex posteriorly in dorsal view. Anterior border of the petiole straight, strongly carinate and slightly denticulate on each side. Ventral process of the petiole very small and sub-triangular. Postpetiole shorter than 1/2 of the gastral tergite I (LT4), with the sides strongly convex in dorsal view. Postpetiolar dorsum with a median, short tumulus close to the posterior border. Postpetiolar sternite anteromedially with a marked, subround projection. Posterior half of the postpetiolar sternite slightly convex. Constriction between postpetiole and gastral segment I strongly impressed. Gastral tergite I convex dorsally and round on the curvature. Gastral sternite I (LS4) very short medially, carinate and slightly protruding anteriorly on the sides. Remaining gastral tergites and sternites curved ventrally.

Legs slightly elongate. Mid tibiae without spur. Spurs of fore legs without a basal spine. Fore basitarsi longer than the mid ones. Hind basitarsi about 1/4 shorter than hind tibiae. Second tarsomere of mid and hind legs longer than the third and fourth tarsomeres and shorter than pretarsus. Pretarsal claws simple. Arolia small.

Sculpture. Head granulopunctate and irregularly rugulose. Mesosoma granulate, with short, irregular rugae and with sparse, very irregular, superficial foveae. Petiole and postpetiole granulate-foveolate, the granulation raised to form small peaks and the foveae deeper than on the mesosoma. Anterior half of the gaster smooth and with rare, small granulation. Posterior half of the gaster with strong, dense granules.

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

Colour dark ferrugineous with slightly lighter antennae and legs.

Measurements in mm and Indices: TL 3.38; HL 0.79; HW 0.68; EL 0.06; SL 0.49; WL 0.91; PeL 0.36; PeW 0.29; HFeL 0.60; HTiL 0.50; HBaL 0.37; LS4 0.14; LT4 0.78; CI 86.1 ; SI 62.0; IGR 0.18.

Queen
(tentative attribution). Differing from the worker in the following details: eyes large, about 1/4 of the head length and with interocellar pilosity. Ocelli well developed. Funicular joints 2-10 slightly broader than long. Mandibles with 5-6 denticles before the apical tooth.

Mesosoma robust and convex in profile. Parapsidal furrows marked. Scutellum convex. Metanotum without tooth or spine-like projection. Basal face of the propodeum short and separate from the declivous face by a carina more marked and sub-angulate laterally.

Fore wings of our type 4, hind wings of our type 3 as defined in the description of the genus.

Sculpture. Rugosities on the mesosoma weakly arranged longitudinally. Mesosoma and scutellum without foveae.

Pilosity as in the worker except for the hair type (2) slightly shorter, rare on the basal face of the propodeum.

Colour light ferrugineous.

Measurements in mm and Indices: TL 3.40-4.03; HL 0.73-0.87; HW 0.62-0.74; EL 0.18-0.21; SL 0.45-0.55; WL 0.96.1.20; PeL 0.34-0.39; PeW 0.28-0.31; HFeL 0.56-0.71; HTiL 0.45-0.58; HBaL 0.32-0.45; LS4 0.16-0.20; LT4 0.85-0.98; CI 84.9-85.0; SI 61.6-63.2; IGR 0.19-0.20.

Type Material
Holotype worker (unique) from Colombia labelled: "Valle, Bosque El Ensueno, K 27 Via mar, 1700 m, 5.VI. 2000, 1 worker, P. Chacon", deposited in the.

Etymology
This species is named after the Catios, the former inhabitants of this part of Colombia.