Osoriellus setifer, 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 : 247

Osoriellus setifer n. sp.

( Figs 26A, C , 27F )

Type material: Holotype, male: Peru: Madre de Dios, Pentiacolla Lodge, Alto Madre de Dios River , (71°13.55'W, 12°39.22'S), 400 m elevation, collected by flight intercept trap, 23.- 26.10.2000, leg. R. Brooks ( KNHM).

Diagnosis: Among the species of this group with dense setation on the fore-body, this species can be differentiated by the flattened area at posterior pronotal angles. The aedeagus is symmetric as in O. setosus , but the apical lobe is thicker.

Description: Length: 6.1 mm. Colouration: Dark brown; legs and antenne slightly lighter brown.

Head: 0.69 mm long, 1.10 mm wide; eyes not prominent, slightly longer than temples; sides of fore-head strongly narrowed in front of eyes; clypeus trapezoidal; anterior edge even; setiferous punctation moderately weak; with wide impunctate midline on vertex; on clypeus punctures deeper than on vertex; yellow setae long; on supraocular area punctures slightly granulate; punctate area with dense netlike microsculpture; surface matt; impuncate midline without microsculpture; surface shiny.

Antennae slightly longer than head and half of pronotum combined; second antennomere oval; third conical and slightly longer than second; following antennomeres more or less quadrate; not increasing in width.

Pronotum: 1.19 mm long, 1.36 mm wide; widest in anterior third; slightly narrowed to anterior angles; more strongly narrowed to posterior angles; in front of posterior angles slightly emarginate; sides close to posterior angles nearly parallel; in dorsal aspect, lateral margin visible throughout ist total length; close to posterior angles slightly thicker than at anterior angles; flattened at anterior angles; setiferous punctation dense and even except at wide impuncate midline; punctures deeper than on head; interstices between punctures slightly shorter than diameter of punctures; irregular microsculpture extremely weak; surface shiny.

Elytra: 1.37 mm long, 1.40 mm wide; with distinctly rectangular shoulders; widest in posterior third; coriaceous ground sculpture weak; dense setiferous punctation distinctly visible; yellow setae long.

Abdomen with dense setiferous punctation and long yellow setae except on moderately wide impunctate midline; netlike microsculpture deep; surface matt.

Protibia: 0.74 mm long, 0.19 mm wide; slender; 8 spines at outer edge; apical spines inserted on moderately long digits; WLR: 0.9; in posterior aspect, comb of inner emargination visible throughout its total length; posterior face with moderately dense setation; on average, setae slightly shorter than protibial width.

Aedeagus rectangularly angulate; both lobes equal in length; apical lobe narrowed to thick apex; apex curved to short hook.

Etymology: The specific name means carrying setae.

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.