The Neotropical species of the genus Osorius G - M, 1829 with remarks to the Neotropical Osoriid complex (Coleoptera: Staphylinidae: Osoriinae) Irmler, Ulrich Beiträge Zur Entomologie = Contributions to Entomology 2010 2010-12-20 60 2 363 426 75BRS BERNHAUER BERNHAUER [184,511,823,841] Insecta Staphylinidae Osorius Animalia Coleoptera 11 374 Arthropoda species alternans    Typematerial examined:    Peru: Lima, leg. Linke, 1 malewithout further data ( syntype, FMNH);   Bolivia:Yuracaris 1 female( syntype, FMNH).  Additional material examined:    Bolivia: Yuracaris,  1500 melevation, 1 specimen( FMNH);   Peru: San Ramon( 75°17' W, 11°02' W), 1 specimen,  9.9.1906, leg. Iconikoff( FMNH);  Iquitos, lowland forest, Rio Napoand Rio Sucusari, 1 specimen,  Dec. 1998, leg. Bracley( BMNH);  Loreto, Boqueron del Padre Abad, 7 specimens,  8.8.1946, leg. F. Woytkowski( AMNH);  San Martin, 2 specimens, 9.3.194, leg. F. Woytkowski( AMNH);  La Merced, 15 kmE, Pasco, 1 specimen,  24.11.1971, leg. R.T.Schuh( AMNH);  Bagua( 78°30' W, 5°38' S), Montenegro, Amazonas, 1 specimen,  2.10.1963, F. Wygodzinski( AMNH);  Tingo Maria( 75°59' W, 9°17' S), 1 specimen,  21.10.1947, leg. J. Pallister( AMNH);  Madre de Dios, Manu National Park, Cocha Otorongo, under bark ( 71°11'58 W, 12°02'1 S),  310 melevation, 5 specimens,  21.10.2000leg. R.W. Brooks( KU, UIC);  Villa Rica( 74.50 W, 10.08 S); 15 kmE, Pasco,  100 melevation, 2 specimens,  24.11.1971, leg. R.T. Schuh( AMNH);  Tambopata: PuertoMaldonado ( 69.12 W, 12.37 S), 15 kmN, ex molassas,  200 melevation, 2 specimens,  11.07.1989, leg. J.S. Ashe( KU);  Madre de Dios: Pentiacolla Lodge, Monk Saki Trail, under bark, 1 specimen,  25.10.2000, leg. R.W. Brooks( KU);   Ecuador: Sucumbios, Sacha Lodge( 76°5' W, 0°5' S), 4 specimens,  22.03.1999, leg. R.W. Brooks( KU, UIC);  Sacha Lodge, 5 specimens,  28.10.2004, leg. Rougemont( RC, UIC);  La Bonita( 77°32' W, 0°24'1 N), 17.5 kmS, Santa Barbara Rd., 1 specimen,  11.10.1998, leg. D. Brzoska( KU);  Napo, Jatun Sacha,  16 kmE Puerto Napo, rain forest, under bark ( 77°37'42 W, 1°03'57 S), 1 specimen,  22.7.2009, leg. U. Irmler( UIC).   Diagnosis: BERNHAUERBERNHAUER (1920) already mentioned the high similarity between  O. alternansand  O. stipes. Even the differences noted by Bernhauer could not be considered to be constant in a larger number of specimens. The short labrum mentioned by BERNHAUERBERNHAUER (1920) is no valid character, because the labrum in  Osoriuscan be moved fore and back by the beetle and is thus variably covered by the clypeus. I found no significant constant characters to identify the two species except in the shape of the aedeagus. After studying the typespecies I was convinced that  O. alternansalternansis synonym to  O. stipes. However, after the study of a number of specimens from the eastern Andean region, no variation was found in the aedeagus of the specimens of this region. It is clearly different from the Central Amazonian specimens. Thus,  O. alternansalternansseems to be a distinct species. The aedeagus in  O. alternansalternanshas a short, very small, even apex, whereas the aedeagus in  O. stipeshas a longer acute apex.   Description:  Length: 11.5 – 13.5 mm. Colour: black.  Head:: 1.5 – 2.0 mm long, 2.5 – 3.1 mmwide; eyes not prominent; slightly shorter than temples; with numerous supraocular and postocular striae; irregular punctation moderately deep and dense; on average distance between punctures two times wider than diameter of punctures; an impunctate space at base of antennae and an adjacent space with sparser punctation on each side of disc; close to neck a further transversal space with sparser punctation; on each side of clypeus with denser granular punctation; few granular punctures also between eyes and neck; on each side of disc with two supraocular setiferous punctures and three setiferous punctures in front of eyes; microsculpture densely netlike reticulate; surface only slightly shiny.  AntennaeAntennaeone third longer than head; 2 ndantennomere short and globular; 3 rdantennomere nearly two times longer than 2 nd; subsequent antennomeres slightly increasing in width; 4 thto 6 thantennomeres more or less quadrate; subsequent antennomeres slightly wider than long.  Pronotum: 2.1 – 2.5 mmlong, 2.6 – 3.3 mmwide; widest at anterior tooth-like prominent angles; narrowed to posterior angles; in front of posterior angles slightly emarginate; a second smooth emargination in anterior half; lateral margin narrow in anterior half, widened in posterior half; punctation deep, but sparser than on head; distance between punctures 2.5 to 3 times wider than diameter of punctures; with small impunctate midline; midline with short furrow in posterior half; netlike microsculpture deeper and more distinct than on head; surface less shiny than on head.  Elytra: 2.6 – 3.3 mmlong, 2.7 – 3.4 mmwide; with coriaceous ground sculpture, but without microsculpture; sparse punctation nearly invisible in coarse ground sculpture; surface shinier than on pronotum and head; nearly polished between striae of ground sculpture.  AedeagusAedeagusrelatively slender with short apical part; apex obtuse and slightly curved back. [107,817,916,940] FMNH Linke Peru Lima 11 374 1 1 Lima syntype FMNH Bolivia Bolivia 11 374 1 1 syntype [107,683,1031,1054] FMNH Bolivia 1500 Yuracaris 11 374 1 1906-09-09 FMNH Iconikoff Peru San Ramon -11.033334 11 374 1 1998-12 BMNH Bracley Peru Iquitos Rio Sucusari Rio Napo 11 374 1 1946-08-08 AMNH F. Woytkowski Peru Boqueron del Padre Abad 11 374 7 Loreto [356,976,1118,1140] AMNH F. Woytkowski Peru San Martin 11 374 2 San Martin 1971-11-24 AMNH La Merced & R. T. Schuh Peru Pasco 11 374 1 Pasco 1963-02-10 AMNH Montenegro & F. Wygodzinski Peru -5.633333 Amazonas 1305 -78.5 Bagua 11 374 1 1947-10-21 AMNH J. Pallister Peru -9.283334 Tingo Maria 1300 -75.98333 11 374 1 2000-10-21 KU, UIC R. W. Brooks Peru 310 -12.033611 Cocha Otorongo 21 -71.19945 Manu National Park 11 374 5 Madre de Dios 1971-11-24 AMNH R. T. Schuh Peru 100 -10.08 Villa Rica 779 -74.5 11 374 2 Pasco 1989-11-07 KU J. S. Ashe Peru 200 -12.37 Puerto 776 -69.12 Tambopata 11 374 2 2000-10-25 KU R. W. Brooks Peru Monk Saki Trail Pentiacolla Lodge 11 374 1 Madre de Dios 1999-03-22 KU, UIC R. W. Brooks Ecuador -0.083333336 Sacha Lodge 1308 -76.083336 11 374 4 Sucumbios 2004-10-28 RC, UIC Rougemont Ecuador Sacha Lodge 11 374 5 1998-11-10 KU La Bonita & D. Brzoska Ecuador 0.4002778 Santa Barbara Rd. 925 -77.53333 11 374 1 2009-07-22 UIC U. Irmler Ecuador -1.0658333 Jatun Sacha 21 -77.628334 11 374 1 Napo