Proceratium longiscapus

Known from a single queen collected at a light trap.

Identification
A member of the micrommatum clade. Differing from all the other species of the clade, in the gyne, by the antennal scapes reaching the cephalic vertex posteriorly and by the antennal joints longer than broad (Baroni Urbani and de Andrade 2003)

Distribution based on Regional Taxon Lists
Neotropical Region: Dominican Republic, Greater Antilles.

Castes
Workers and males are unknown.

Nomenclature

 * . Proceratium longiscapus De Andrade, in Baroni Urbani & De Andrade, 2003b: 190, figs. 81, 82 (q.) DOMINICAN REPUBLIC.
 * Type-material: holotype queen.
 * Type-locality: Dominican Republic: Bonao, 29.viii.1997, blacklight trap (C. O’Brien & R. Baronowski).
 * Type-depository: MCZC.
 * Status as species: Lubertazzi, 2019: 161.
 * Distribution: Dominican Republic.

Queen
Head longer than broad and with subparallel sides. Vertex in full face view weakly convex. Clypeus reduced, subround and slightly longer than the antennal sockets. Antenna1 socket with broad torulus. Frontal carinae close each other, not covering the antennal insertions. Frontal area behind the frontal carinae weakly convex. Lateral expansions of the frontal carinae relatively narrow, feebly raised and parallel. Genal carinae marked. A sulcus between the genal carinae and the gular area. Eyes large, about 1/4 of the head length and with ocular pilosity. Ocelli well developed. Scapes reaching the vertexal margin. First funicular joint about 1/2 longer than broad. Funicular joints 2-10 longer than broad. Last funicular joint about as long as the sum of joints 6-10. Mandibles with 4 denticles before the apical tooth. Palp formula probably 3,2.

Mesosoma convex in side view. Parapsidal furrows marked. Scutellum with the sides converging posteriorly and with the posterior border rounded. Metanotum without triangular tooth. Basal face of the propodeum short, weakly angulate laterally, incised and almost as flat as the declivous face medially. Propodeal lobes round. Propodeal spiracles small.

Petiole longer than broad, with the sides subparallel in the anterior third and convex posteriorly in dorsal view. Anterior border of the petiole almost straight and carinate. Ventral process of the petiole corresponding to a narrow, crenulate, longitudinal lamella. Postpetiole slightly shorter than 1/2 of the gastral tergite I (LT4), with the sides gently convex in dorsal view. Postpetiolar sternite anteromedially with a subtriangular projection. Posterior half of the postpetiolar sternite flat. Constriction between postpetiole and gastral segment I impressed. Gastral tergite I convex on the curvature. Gastral sternite I short medially. Sides of gastral sternite I flat and not protruding anteriorly. 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 116 shorter than hind tibiae. Second tarsomere of mid and hind legs longer than the third and fourth and slightly shorter than pretarsus. Pretarsal claws simple. Arolia very small.

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

Sculpture. Head with small reticulation, sparsely rugulose and granulate. Pronotum, scutellum, pleurae and basal face of the propodeum with small granulation and rare, short, thin, rugosities, the rugosities ticker on the metapleurae. Mesonotum with superficial, srnall piligerous punctures. Petiole and postpetiole granulate. First gastral tergite superficially smooth and covered by small piligerous punctures, larger on the sides. Legs punctate.

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

Colour light brown.

Measurements in mm and Indices: TL 3.15; HL 0.71; HW 0.58; EL 0.18; SL 0.60; WL 0.90; PeL 0.31; Pew 0.26; HTiL 0.48; HBaL 0.40; LS4 0.19; LT4 0.80; CI 81.6; SI 84.5; IGR 0.24.

Type Material
Holotype gyne from the Dominican Republic labelled "Dominican Republic, Bonao, 29.VIII.1997, C. O'Brien & R. Baronowski, blacklight trap", In. MCZ-ENT0035686

Etymology
From the Latin longus (= long) and scapus (= stalk), referred to the most salient morphological trait of this species.

References based on Global Ant Biodiversity Informatics

 * Baroni Urbani C., and M.L de Andrade. 2003. The ant genus Proceratium in the extant and fossil record (Hymenoptera: Formicidae). Museo Regionale di Scienze Naturali, Monografie 36: 1-480.
 * Perez-Gelabert D. E. 2008. Arthropods of Hispaniola (Dominican Republic and Haiti): A checklist and bibliography. Zootaxa 1831:1-530.