Osoriellus coriaceus, 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 : 263

Osoriellus coriaceus n. sp.

( Figs 51 A-C, 95F)

Type material: Holotype, male: Brazil: Bahia, Urucuca, Cerro Grande, primary Atlantic forest (39°3.43'W, 14°25.17'S), 120 m elevation, 28.1.1995, leg. D. Agosti ( AMNH).

Paratypes: Brazil: 4 females with same data as holotype ( AMNH, UIC) .

Diagnosis: The species can be easily identified by the coriaceous punctation of the head that is unique in the similarly sized species of the Neotropical Osoriellus species.

Description: Length: 3.3 – 3.4 mm. Colouration: Black; legs and antennae reddish.

Head: 0.47 mm long, 0.68 mm wide; eyes slightly longer than temples and slightly prominent; sides of fore-head sinuate; anterior edge of clypeus slightly emarginate and each angle with short granule; setiferous punctation dense, coriaceous and striate; surface matt.

Antennae with second antennomere thick and oval; thicker than three following antennomeres; third antennomere conical and shorter than second; fourth to sixth antennomeres as wide as or slightly wider than third, but approximately quadrate; seventh to eleventh antennomeres much thicker than preceding antennomeres, but only slightly wider than long.

Pronotum: 0.65 mm long, 0.70 mm wide; widest at anterior angels; slightly convergent to smoothly rounded posterior angles; lateral margin narrow; in dorsal aspect, not visible in anterior fourth; setiferous punctation dense; punctures large; on average, interstices between punctures half as wide as diameter of punctures; narrow midline impunctate; without microsculpture; surface polished, but only slightly shiny, because of dense punctation.

Elytra: 0.83 mm long, 0.68 mm wide; with dense and deep ground-sculpture; dense punctation slightly visible in coriaceous ground-sculpture; surface matt.

Abdomen with dense setiferous punctation, but less dense than on elytra; narrow midline impunctate; surface polished and shiny.

Protibia: 0.43 mm long, 0.12 mm wide; at outer edge with 6 long spines; apical spines directly inserted on outer edge; WLR: 3.0; in posterior aspect, comb at inner emargination totally visible; posterior face densely covered by yellow setae.

Aedeagus with smoothly curved apical lobe; apex obtuse.

Etymology: The specific name refers to the dense coriaceous punctation of the head.

Figures

Fig. 48-52: Osoriellus-s. str.-group: Osoriellus lewisi (48); O. huggerti (49), O. flaveolus (50), O. coriaceus (51), O. latitibialis (52); antenna (A), protibia (B), aedeagus in lateral aspect (C); scale bar: 0.1 mm.