Osoriellus ocularis, Irmler, 2014

Irmler, Ulrich, 2014, The Neotropical species of the genus Osoriellus FAGEL, 1959 (Coleoptera: Staphylinidae: Osoriinae), Beiträge Zur Entomologie = Contributions to Entomology 64 (2), pp. 231-354: 238-239

publication ID

http://doi.org/ 10.21248/contrib.entomol.64.2.231-354

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scientific name

Osoriellus ocularis

n. sp.

Osoriellus ocularis   n. sp.

( Figs 6 View Fig A-D, 11B)

Type material: Holotype, male: Brazil: Pará , Jacareacanga (57°45.38'W, 6°13.24S), X.1959, leg. M. Alvarenga ( INPA). GoogleMaps  

Paratypes: Brazil: 1 male, 7 females with same data as holotype ( INPA, UIC) GoogleMaps   ; French Guiana: Nason; Marowijne River, Wanaboo (54°26'36"W, 4°43'35"N), flight intercept trap, male, 5.6.1999, leg. Z.H. Falin ( KNHM) GoogleMaps   ; Bolivia: Beni, Ilha Flores (63°07'W, 12°46'S), Rio Iténez , 9 females, 9 males, 7.8.1964, leg. J.K. Bouseman & L. Lussenhop ( AMNH, UIC) GoogleMaps   ; Beni, Capivara , 30 km E Versales (63°16'W, 12°43'S), female, 22.7.1964, leg. J.K. Bouseman & L. Lussenhop ( AMNH) GoogleMaps   ; Beni, Guayaramerin, Fundo Nuevo Cuba, Soil Zoological Expedition , NO. 408, netted from vegetation, 2 females, 22. + 26.11.1966, leg. J. Balogh, L.S. Mahunka, Zicsi ( NMB)   .

Diagnosis: Among the species with a crenate front edge of the clypeus, i.e. O. oculatus   and O. hanagarthi   , the species can identified by its small size in combination with large, prominent eyes. In dorsal aspect, the space between eyes is only 6 times as wide as the diameter of eyes. The teeth at clypeal angles are longer than in O. oculatus   and O. hanagarthi   . Furthermore, the apical lobe of the aedeagus is longer than in the two other species.

Description: Length: 3.7 – 3.8 mm. Colouration: Head and pronotum dark brown, abdomen, elytra, legs, and antennae light red; elytra at posterior margin indistinctly darker.

Head: 0.65 mm long, 0.80 mm wide; eyes large and prominent; in dorsal aspect, space between eyes 6 times as wide as diameter of eyes; sides of fore-head convergent to front edge of clypeus in even concave curve; front margin of clypeus crenate and with larger teeth at angles; on large supraocular area with dense and coarse setiferous punctation; clypeus with distinctly finer and sparser setiferous punctation, setae yellow and pointing to apical centre; wide area on vertex impunctate and surface polished and shiny; on remaining vertex and on clypeus with distinct netlike microsculpture; surface matt except small shiny area at base of antennae.

Antennae with first antennomere as long as three following ones, second antennomere oval and longer than conical third antennomere; antennomeres four to six more or less quadrate and not wider than preceding antennomeres; following antennomeres distinctly thicker.

Pronotum: 0.67 mm long, 0.75 mm wide; widest at anterior margin; evenly convergent to posterior margin; at posterior angles only two-third as wide as at anterior angles; in dorsal aspect, lateral margin fine; visible in its total length; setiferous punctation coarse and deep; interstices between punctures only one-fourth of diameter of punctures; yellow setae pointing to middle; punctures close to impunctate midline in indistinct rows of up to 9 punctures; without microsculpture, but with sparse micro-punctation; surface shiny.

Elytra: 0.90 mm long, 0.80 mm wide; with coriaceous ground-sculpture; surface less shiny than pronotum; setiferous punctation as coarse and deep as on pronotum; yellow setae pointing distad.

Abdomen densely and deeply punctate; yellow setae pointing distad.

Protibia 0.50 mm long, 0.13 mm wide; moderately thick and with 9 long spines at outer edge; apical spines inserted on short digits; WLR: 3.8; in posterior aspect, inner edge nearly straight and comb covered in middle; posterior face densely covered by long yellow setae.

Aedaegus with long apical lobe; apical lobe even longer than basal lobe and widely rounded at obtuse apex; only two sensillae at lateral inner edge of apex.

Etymology: The specific name derived from the Latin word oculus meaning eye and refers to the large eyes.

Osoriellus oculatus ( SHARP, 1876)   new combination ( Figs 7 View Fig A-D, 11C)

Osorius oculatus SHARP, 1876: 386  

Type material examined: Brazil: Tefé (64°41'W, 3°21'S), without further data (holotype BMNH) GoogleMaps   .

Further material examined: Brazil: Mato Grosso, Cáceres (54°42'W, 16°03'S), 3 females, 7 males, 2./ 4.12.1955, leg. M. Alvarenga ( UIC) GoogleMaps   .

Diagnosis: Within the O.- oculatus   -group, the species is characterised by its prominent eyes and the 3 short teeth on each side of the middle at anterior edge of the clypeus. The punctation of the pronotum is similar as in O. hanagarthi   , but the shape of the pronotum is different. In O. oculatus   , the pronotum is more deeply sinuated shortly in front of the posterior angles than in O. hanagarthi   . The aedeagi are very similar in O. oculatus   and O. hanagarthi   , but the apex of the aedeagus in O. hanagarthi   is obtuse, whereas it is acute O. oculatus   .

Description: Length: 4.2 – 4.7 mm. Colouration: Dark brown; legs and antennae reddish.

Head: 0.60 mm long, 0.85 mm wide: with large and prominent eyes; eyes at least half as long as temples; angles of clypeus produced to short teeth; adjacent to tooth two smaller granules; middle not granulate, but slightly produced; clypeus and disc densely and coarsely punctate; interstices between punctures almost one-fourth as wide as diameter of punctures; large supraocular and indifferent area on vertex impunctate; surface moderately shiny; on parts of vertex indistinct weak microsculpture present.

Antennae with oblong second antennomere; third antennomere conical; one-fourth shorter than second; antennomeres 4 to 6 quadrate and equal in width; antennomeres 7 to 11 much wider and longer than preceding ones, slightly wider than long.

Pronotum: 0.80 mm long, 0.85 mm wide; widest at anterior angles, in anterior two-third slightly narrowed; in posterior third more strongly convergent to posterior angles; posterior angles obtusely rounded; lateral margin fine; in dorsal aspect, not visible at anterior angles; surface with large and deep setiferous punctures; interstices between punctures approximately half as wide as diameter of punctures; at each side of wide impunctate midline with row of 10 to 11 punctures partly forming coriaceous furrow; without microsculpture, but with sparse micro-punctation; surface shiny.

Elytra: 1.0 mm long, 0.90 mm wide; with dense, partly coriaceous setiferous punctures; punctures forming irregular rows; punctation laterally sparser than on disc; surface shiny, but partly with weak coriaceous groundsculpture.

Abdomen with dense setiferous punctation; setae pointing to middle; interstices between punctures less than one-fourth of diameter of punctures.

Protibia 0.48 mm long, 0.17 mm wide; with 9 spines at outer edge; apical spines inserted on short digits; WLR: 2.1; in posterior aspect, comb at inner emargination visible, but partly covered in apical part; on posterior face with dense setation.

Aedeagus stout with short apical lobe and four sensillae at inner edge.


Instituto Nacional de Pesquisas da Amazonia


The Educational Science Museum [=Kuwait Natural History Museum?]


American Museum of Natural History


Naturhistorishes Museum














Osoriellus ocularis

Irmler, Ulrich 2014

Osorius oculatus

SHARP, D. 1876: 386