Osorius brasiliensis GUÉRIN, 1829

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 : 378-379

Osorius brasiliensis GUÉRIN, 1829 ( Figs 4 a-f, 38 B)

Osorius asymetricus FAUVEL, 1901: 72 new synonymy

Type material examined:

Brazil: without further data, 1 female det. as O. tardustardus Dej (neotype, BMNH) ; Venezuela: 1 male without further data (syntype of O. asymetricusasymetricus with remarks of Fauvel given by Sharp ‘trés semblable a canaliculatus ’ ,, ( IRSNB).

Additional material examined:

Venezuela: Ve Caripe (10°10' N, 63°63' W), 7.4.1998, leg. M. v. Tschirnhaus, 21 specimens collected in rotten log ( UIC) ; Caracas (66°53' W, 10°26' N), San Esteban (70°06' W, 10°57' N), 1.11.1888, leg. Simon ( O. asymetricus )) ( IRSNB) ; 1 specimen det. as O. intermediusintermedius by Cameron ( BMNH) ; près de Puerto Cabello , 1 specimen, 1st trimestre 1877, leg. H. de Sagan ( BMNH) ; as punctatelluspunctatellus Bernh. manuscript name, 1 specimen, Nov. 1888, leg. E. Simon ( BMNH) , 2 specimens, Nov. 1888, leg. E. Simon ( BMNH, IRSNB) ; 1 specimen, Mus. Drews ( ZMUK) ; Maracay (67°35' W, 10°14' N) 19 km N, road to Choroni, litter near stream, 1 specimen, 16.4.1994, leg. L. Herman ; 1 specimen, 26.4.1946, leg. W. Beebe, Rancho Grande, 1 specimen, 21.6.1946, leg. W. Beebe ( AMNH) ; Miranda (68°23' W; 10°08' N), 19 km N, road to Choroni, Agua Blanca, humid trop. forest, 1 specimen, 15.02.1987, leg. M.G. Paoletti ( AMNH) ; Tovar (71°45' W, 8°20' N), 1 specimen, det. as O. asymetricusasymetricus by Fauvel ( IRSNB) ; Puerto Cabello (68°00' W, 10°27' N), 1 specimen, leg. E. Bugnion ( IRSNB) ; Carabobo (61°24' W, 6°18' N), Mun. Bejuma, Via Palmichal, 1 specimen, 15.11.2005, leg. L. Brachat ( AC) ; Trinidad: 1 specimen, 1904, leg. F. Birch ( BMNH) ; Tobago, St. Mary's Pa. Gilpin Trace , 1 specimen, 14.6.1991, leg. D. Brzoska ( KU) ; Guyana: without further data, 2 specimens, leg. Lansberg ( ZMUK) ; French Guyana: 1 specimen without further data, coll. Sharp ( BMNH) ; Roura (52°19' W, 4°43' N), 2 specimens, 8.1.1999, leg. P. Krásensky ( JC) ; Saül (53°12' W, 3°37' N), Les Eaux claires, 1 specimen under bark, 14.11.1995, leg. A. Berkov ( AMNH) ; Matoury (52°19' W, 4°50' N), trail, Sentier de la Miranda, primary tropical rainforest under wood and bark, 2 specimens, 18.12.2004, leg. J. Huff ( AMNH) ; Suriname: Sarmaca , 1 specimen under bark, 6.8.1980, leg. M. Russell ( BMNH) ; Columbia: Santa Marta (74°08' W, 11°13' N), Sierra Nevada, Buritaca-Remol ino trail, 1 specimen, 11.12.1974, leg. M. Cooper ( BMNH) ; Columbia without further data, det. as tardustardus Déjean, Mus. Drews (ZMUK) ; Ecuador: 1 specimen, 1879, leg. Buckley ( BMNH) ; Sucumbios, Shushufindi (76°38' W, 0°11' S), 1 specimen, 8.12.2004, leg. P. Banar ( JC) ; 1 specimen without further data, 1879, leg. Buckley ( BMNH) ; Brazil: Mato Grosso (51°47' W, 12°50' S), 1 specimen, 10.10.1968, gallery forest, leg. O. W. Richards ( BMNH) .

Diagnosis:

The species is very similar to O. intermedius and can be hardly distinguished from that species without analysis of the aedeagus. The indistinct depressions at the posterior angles of pronotum seem to be absent in O. intermedius , and the elytra seem to be more shiny in O. brasiliensis . The prosternal process in O. brasiliensisbrasiliensis is more triangularly shaped than in O. intermediusintermedius and in apical aspect, the process is usually emarginate in the middle. However, the shape of the process is varying in both species and reflects no consistent character. The aedeagus in O. brasiliensisbrasiliensis is slightly asymmetric with a straight short apex, while apex in O. intermediusintermedius is hook-like and thicker. As already mentioned for O. alternans , the asymmetric shape of labrum in O. asymmetricus described by FAUVEL (1901) is not valid because of the movable character of the labrum.

Description:

Length: 12.5 – 14.5 mm. Colour: black.

Head :: 1.8 mm long, 2.7 mm wide; with eyes half as long as temples; front edge of clypeus emarginate with two or three obtuse short lateral teeth on each side; central part of emargination indistinctly prominent; with reduced supraocular striae and distinct postocular striae; 3 to 4 supraocular granular setiferous punctures; punctation on disc distinct, but sparse; distance between punctures on average twice as wide as diameter of punctures; one granular setiferous puncture on each side of middle near neck; isodiametric microsculpture distinct; surface shiny.

AntennaeAntennae with 2 nd antennomere oval; half as long as conical 3 rd antennomere; antennomeres 4 to 5 longer than wide and decreasing in length; subsequent antennomeres more or less quadrate, but penultimate antennomeres slightly shorter than 6 th antennomere.

Pronotum: 2.2 mm long, 2.8 mm wide; widest at tooth-like prominent anterior angles; in anterior half lateral margin small; distinctly widened to posterior angles; indistinct flat depression at posterior angles; punctation as dense and sparse as on head, but varying in size; with deeper and larger punctures near posterior edge and on lateral disc; between normal, large punctation with sparse micro-punctation; on each side of middle a slightly larger granular setiferous puncture; longitudinal depression in midline varying in depth; distinct microsculpture isodiametric; as deep as on head, but surface slightly mattet; anterior prosternal process triangular; with two or three granular setiferous punctures; front edge of process slightly concave.

Elytra: 3.0 mm long, 2.9 mm wide; with weak and sparse coriaceous ground sculpture; punctation deeper and larger than on pronotum, but distinctly sparser; without remains of microsculpture; surface nearly polished.

AedeagusAedeagus with short apical part; broad at base and abruptly narrowed shortly in front of acute apex.

Figures

Fig. 4: Osorius brasiliensis. - Fig. 5: O. intermedius. - Fig. 6: O. columbinus (a: front body, b: antenna, c: aedeagus in ventral and lateral aspect, d: prosternal process, e: head in lateral aspect; scale bar a, b, e: 1 mm, c, d: 0.5 mm)