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

Osoriellus ocularis n. sp.

( Figs 6 A-D, 11B)

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

Paratypes: Brazil: 1 male, 7 females with same data as holotype ( INPA, UIC) ; 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) ; 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) ; Beni, Capivara, 30 km E Versales (63°16'W, 12°43'S), female, 22.7.1964, leg. J.K. Bouseman & L. Lussenhop ( AMNH) ; 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.

Figures

Fig. 6-10: Osoriellus-oculatus-group: Osoriellus ocularis (6), O. oculatus (7), O. hanagarthi (8) O. sexdentatus (9) O. denticornis (10); antenna (A), protibia (B), aedeagus in lateral aspect (C), anterior edge of clypeus (D); scale bar: 0.1 mm.