Osorius granulatus BERNHAUER

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 : 387-389

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https://doi.org/ 10.21248/contrib.entomol.60.2.363-426

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scientific name

Osorius granulatus BERNHAUER


Osorius granulatus BERNHAUER View in CoL ,, 1920: 137 (Fig. 10 a-b, 39 C)

Type material examined:

Brazil: Rio de Janeiro, Colonia alpina 1 female (holotype, FMNH) .

Additional material examined:

Brazil: Amapa, Serra de Navio , 1 female, 5.12.1959, leg. R. Arlé ( UIC) .


The species can be differentiated from the similar large species by the granular punctation of the head and the distinctly thicker last antennomeres. Unfortunately, only females could be studied.


Length: 9.5 mm. Colour: black.

Head :: 1.5 mm long, 1.8 mm wide; punctation moderately dense; a large area on posterior portion of head without punctures; front head with dense granular punctures; two small areas dorsad of antennal base without punctures; isodiametric microsculpture dense and deep; surface scarcely shiny; clypeus with obtuse, distinctly prominent angles; between tooth-like angles with deep emargination; labrum more than twice as wide as long; scarcely projecting clypeal emargination; eyes 1/3rd as long as temples; with few short striae behind eyes and several granular punctures dorsad to eyes.

AntennaeAntennae thick and stout; 2 nd antennomere oval; 3 rd one conical and as long as 2 nd; antennomeres 4 to 6 quadrate; subsequent antennomeres wider than long and much thicker than preceding ones. Pronotum: 1.6 mm long, 1.8 mm wide; widest at tooth-like anterior angles; more or less continuously narrowed to posterior angles; lateral margin narrow at anterior angles; slightly wider at posterior angles; posterior edge margined; punctation deep and sparse; distance between punctures at least two times wider than diameter of punctures; with smooth non-punctuate midline; isodiametric microsculpture deep and dense; surface scarcely shiny.

Elytra: 2.0 mm long, 1.8 mm wide; with weak coriaceous ground sculpture and few granular punctures; surface shiny.

Osorius guianensis sp. n. (Figs 26 a-c, 37 D)

Type material:

Holotype, male: British Guyana: Kamakusa, Jan. 1923, without information about the collector, but with No. Acc. 24895 ( AMNH).

Paratypes: one male with the same data as in holotype ( AMNH); French Guyana: Saül, Eaux Claires, 3.5 mi N Saül (3°38-40' N, 53°13-14' W), 155-260 m elevation , 2 males, Oct /5 – 13 / 95, leg. L. Herman, collected in fig fruit fall ( AMNH, UIC) .


The species is extremely similar to Osorius brasiliensisbrasiliensis and O. stipes / alternans concerning overall feature, shape of aedeagus, and density of punctation on pronotum. However, it is smaller than the two species. Striae of head are also present in the supraocular space as in O. stipes / alternans , whereas they are only present in the postocular space in O. brasiliensis . Aedeagus is very similar to both species. In O. guianensis , apex of aedeagus is pointing backwards as in O. alternans , whereas it is straight in O. brasiliensis . In O. guianensis , aedeagus is broader than in O. stipes , O. alternans , and O. brasiliensis .


Length: 11.0 mm. Colour: black, antennae and legs dark brown.

Head :: 1.7 mm long, 2.3 mm wide; with short, not prominent eyes; temples twice as long as eyes; front edge of clypeus dilated at both outer angles and with central emargination; front edge undulate; with numerous supraocular striae continued behind eyes; punctation deep and dense, but irregular; a space at base of antennae, in centre of clypeus, and at posterior disc without punctures; on average, distance between punctures half as wide as diameter of punctures; with two supraocular, setiferous and granular punctures; a pair of setiferous punctures on disc near neck; a few setiferous punctures in front of anterior edge of eyes; surface without microsculpture, shiny.

Antennae with 2 nd antennomere short, but longer than wide; 3 rd antennomere 1.5 times as long as 2 nd; subsequent antennomeres increasing in width; 4 th and 5 th antennomeres quadrate; subsequent antennomeres slightly wider than long.

Pronotum: 1.9 mm long, 1.9 mm wide; widest at anterior angles; anterior angles tooth-like prominent; sides behind anterior angles slightly narrowed in anterior half; in posterior half distinctly narrowed; a weak lateral emargination in front of posterior angles; lateral margin narrow at anterior angles; distinctly widened in posterior half; punctation deep and dense, but on average less dense than on head; short midline impunctate and with a longitudinal stria in posterior half; distance between punctures irregularly; between half as wide as to as wide as diameter of punctures; near depression at posterior angles with sparser punctation; with weak netlike microsculpture, but surface nevertheless shiny.

Elytra: 2.4 mm long, 2.4 mm wide; with deep coriaceous ground sculpture; surface less shiny than on pronotum.

Abdomen with extremely sparse and fine punctation; microsculpture on first visible tergite deep and distinct; surface matte; on subsequent tergites microsculpture weaker and surface shinier; on tergite VIII with numerous granular punctures.

Aedeagus short and broad, pear-shaped in ventral aspect; apex short, pointing shortly backwards.


The specific name derived from the region where the species was found.


Field Museum of Natural History


American Museum of Natural History













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