Osorius canaliculatus SOLSKY, 1870

Irmler, Ulrich, 2010, The Neotropical species of the genus Osorius G - M, 1829 with remarks to the Neotropical Osoriid complex (Coleoptera: Staphylinidae: Osoriinae), Beiträge Zur Entomologie = Contributions to Entomology 60 (2), pp. 363-426 : 380-381

Osorius canaliculatus SOLSKY ,, 1870: 265 ( Figs 7 a-c)

Material examined:

Guatemala: Senahu (89°49' W, 15°25' N), 1 specimen, leg. Champion ( BMNH) ; Nicaragua: San Carlos (84°45 N, 11°07 N), Biologico Bartola, Selva alta perenifolia, ex troncos posridos, 2 specimens, 9.2.2000, leg. J. Marquez ( UNAM) ; Costa Rica: Heredia: La Selva (84°01' W, 10°26' N), 3.2 km SE, P. Viejo, flight intercept trap, 1 specimen, 10.06.1996, leg. R. Hanley ( KU) , from misc. mushrooms, 1 specimen, 18.05.1993, leg. J.S. Ashe ( KU) ; Puerto Viejo, Biol. Stat. (83°59' W, 10°26' N), 1 specimen, 18.2.1985, leg. L. Herman ( AMNH) ; Tapanti (83°47' W, 9°42' N), Vicente , 1 specimen, 2.1941, leg. A. Bierig ( AMNH) ; San José, Puerto Quepos (84°10' W, 9°25' N), Rio Damitas , 1 specimen, 16.8.1962, leg. C.D. Michener ( KU) ; Panama: La Fortuna (82°12' W, 8°46' N), Estacion Biologica (82.12 W, 8.46 N), 1250 m elevation, 3 specimens, 13.07.1995, leg. A.R. Gillogly ( KU) ; Bocas del Toro (82°14' W, 9°20' N), 7 km N Boquete, La Culebra trail, 3 specimens, 15.07.1995, leg. A.R. Gillogly ( KU, UIC) ; Bugaba (82°37' W, 8°28' N), leg. Champion ( BMNH) ; Chiriqui, Tres de Noviembre Trail, upper Rio Chiriqui drainage, 1400 m elevation, 1 specimen, 2.1976, leg. C. Myers ( AMNH) .

Diagnosis:

The species is extremely variable in size, density of punctation, microsculpture on the fore body, and the shape of clypeal front edge. It resembles O. brasiliensisbrasiliensis and O. intermediusintermedius in the absence of supraocular striae. Specimens of O. canaliculatuscanaliculatus with distinctly developed microsculpture and punctation can hardly be distinguished from O. brasiliensis , whereas the presence of the depressions at posterior angles and the longitudinal depression in the midline of the pronotum are differentiating characters to O. intermedius . Those specimens can be distinguished from O. brasiliensisbrasiliensis by the thick anterior prosternal process and the keel-like apex of the aedeagus. In O. canaliculatuscanaliculatus the anterior prosternal process never shows a triangular shape in lateral aspect.

Description:

Length: 14.5 – 17.5 mm. Colour: black.

Head :: 1.8 mm long, 2.8 – 3.5 mm wide; eyes not prominent, half as long as temples; front edge of clypeus with broad; obtuse lateral prominence and emargination in between; lateral prominence divided into an outer broad obtuse tooth and an inner small acute tooth; in intermediate gap with setiferous puncture; anterior emargination with irregular wide medial prominence that might reach lateral prominence in size; punctation irregularly dense and deep; distance between punctures partly not wider than diameter of punctures, partly twice or more than three times wider than diameter of punctures; on clypeus several granular setiferous punctures; with few granular setiferous punctures on lateral disc; three to five supraocular granular setiferous punctures; without supraocular striae, but with few postocular striae; microsculpture moderately deep and dense varying in distinctness; surface thus varying between slightly shiny and nearly polished.

AntennaeAntennae with 2 nd antennomere longer than wide, but only half as long as conical 3 rd antennomere; antennomeres 4 to 7 longer than wide, but successively decreasing in length; subsequent antennomeres quadrate.

Pronotum: 2.1 – 3.0 mm long, 2.7 – 3.7 mm wide; widest at anterior tooth-like prominent angles, with moderately distinct emargination in front of posterior angles; shape in anterior half varying from smoothly rounded to more or less straightly narrowed; lateral margin small at anterior angles; distinctly widened to posterior angles; at posterior angles with indistinct depression; with irregular punctation as on head; partly with larger punctures, partly with small punctures; micro-punctation also present; punctation varying in density; partly distance between punctures as wide as diameter of punctures, partly more than three times wider than diameter of punctures; microsculpture also varying between specimens from nearly absent to distinctly present; if present, microsculpture isodiametric; surface thus varying between nearly polished to slightly shiny; a distinct longitudinal depression always present; anterior prosternal process thick with at least 4 to 5 granular setiferous punctures in lateral aspect, anterior edge convex.

Elytra: 2.7 – 3.3 mm long, 2.7 – 3.3 mm wide; with coriaceous ground sculpture; sparse and large punctation scarcely visible in deep ground sculpture.

AedeagusAedeagus more or less circular, with carinate apex.

Figures

Fig. 7: Osorius canaliculatus. - Fig. 8: O. boops. - Fig. 9: O. affinis. - Fig. 10: O. granulatus (a: front body, b: antenna, c: aedeagus in ventral and lateral aspect scale bar: a - b: 1 mm, c: 0.1 mm).