Osoriellus hirtulus ( FAUVEL, 1891 ) 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 : 245-246

Osoriellus hirtulus ( FAUVEL, 1891) new combination ( Figs 21C , 27A )

Osorius hirtulus FAUVEL, 1891: 92

Type material: Venezuela: Colonia Tovar, 2 males, 2 females, 1.11.1888, leg. E. Simon (lectotype and syntypes ISBN).

Diagnosis: Among the species of this group with dense setiferous punctation of the pronotum, O. hirtulus is characeterised by its large size and the slightly emarginate clypeus.

Description: Length: 7.4-7.8 mm. Colouration: Black, legs dark red; antennae black.

Head: 1.2 mm long, 1.4 mm wide; eyes small and not prominent, temples one-third longer than eyes; front edge of clypeus with obtuse large prominence at each side and a deep emargination between them; with deep and dense setiferous punctures; distance between punctures on average as wide as diameter of punctures; small space on posterior disc and at base of antennae without punctures; setae yellow; shorter on clypeus than on disc; without microsculpture; surface shiny.

Antennae as long as head; second antennomere globular; third oval, half times longer than second antennomere; following antennomeres approximately quadrate; increasing in width.

Pronotum: 1.4 mm long, 1.6 mm wide; widest at anterior angles; continuously convergent to obtusely rounded posterior angles; at anterior angles one-third narrower than at posterior angles; lateral margin slightly elevated to posterior angles; setiferous punctures deeper and denser than on head; with wide impunctate midline; yellow setae long; pointing posteriad; without microsculpture; surface polished.

Elytra: 1.5 mm long, 1.35 mm wide; with similar punctation as on pronotum, but with weak coriaceous ground-sculpture, surface less shiny than pronotum; yellow setae pointing backwards.

Abdomen with similar setiferous punctation as on elytra and pronotum; base of abdominal segments with small transverse depression.

Protibia: 1.01 mm long, 0.32 mm wide; 8 spines on outer edge; apical spines on long digits; WLR: 0.4; in posterior aspect, comb of inner emargination nearly totally visible; posterior face sparsely covered by long yellow setae; on average, setae as long as protibial width.

Aedeagus nearly symmetric; apical lobe narrow and slightly pointing to left side.

Figures

Fig. 21-26: Osoriellus-hirtulus-group: Osoriellus hirtulus (21), O. setosus (22), O. pubescens (23), O. pubicollis (24), O. setulosus (25), O. setifer (26); antenna (A), protibia (B), aedeagus in ventral and lateral aspects (C); scale bar: 0.1 mm.

Fig. 27: Osoriellus-hirtulus-group: Head and pronotum and elytra of Osoriellus hirtulus (A), O. pubicollis (B), O. setulosus (C), O. pubescens (D), O. setosus (E), O. setifer (F); scale bar: 0.5 mm.