Osoriellus fumarius, 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 : 269-270

Osoriellus fumarius n. sp.

( Figs 92 A-C, 100F)

Type material: Holotype, male: Peru: Huanuco Prov., Panguana, Cocha , collected between June – October 1976, leg. W. Hanagarth ( UIC).

Diagnosis: The species is very similar to O. caliginosus concerning the sligthly sinuate sides of the pronotum. The further differentiating characters are described under O. caliginosus .

Description: Length: 6.4 mm. Colouration: Black; legs and antennae dark brown; elytra and abdomen lighter brown.

Head: 0.81 mm long, 1.33 mm wide; eyes slightly prominent; approximately twice as long as temples; sides of fore-head narrowed to slightly produced anterior angles in smoothly concave curve; anterior edge of clypeus slightly emarginate; setiferous punctation moderately deep and irregularly dense; on clypeus much sparser than close to neck; wide midline, area at base of antennae and transverse oval area close to neck impunctate; on clypeus, interstices between punctures at least as wide as diameter of punctures; on vertex, interstices between punctures approximately half as wide as diameter of punctures; on supracocular area punctation still denser; partly coriacous; setae long and yellow; isodiametric microsculpture dense, but weak; surface slightly shiny.

Antennae slightly longer than head; second antennomere oval; slightly longer than conical third antennomere; antennomeres four to six as wide as preceding antennomeres, but quadrate; following antennomeres slightly wider than preceding antennomeres and also quadrate; last antennomere elongately oval and less wide than tenth antennomere.

Pronotum: 1.19 mm long, 1.42 mm wide; widest close to rectangular anterior angles; in anterior half slightly narrowed; in posterior half strongly narrowed in concave curve to rectangular posterior angles; lateral margin distinct; in dorsal aspect, covered close to anterior angles; widened close to posterior angles; setiferous punctation deep and moderately dense; on average, interstices between punctures approximately twice as wide as diameter of punctures; wide midline impunctate; isodiameteric microsculpture as dense as but deeper than on head; surface matt.

Elytra: 1.50 mm long, 1.49 mm wide; shoulders shortly rounded; sides slightly widened to posterior third; setiferous punctation as deep as but denser than on pronotum; coriacous ground-sculpture weak, but isodiametric microsculpture as deep as and as dense as on pronotum; surface matt.

Abdomen with dense setiferous punctation; narrow midline impunctate; netlike microsculpture weak; surface shiny.

Protibia: 0.63 mm long, 0.23 mm wide; nearly semicircular; outer edge with 9 spines; apical spines inserting on very short digits; WLR: 1.8; in posterior aspect, comb at inner emargination visible throughout its total length; posterior face with moderately dense setation.

Aedeagus angulate in obtuse angle; basal lobe thick; apical lobe more slender; apical lobe evenly narrowed from base to obtuse apex; inner edge of apical lobe with numerous sensillae.

Etymology: The specific name fumarius derives from the same Latin word and means dark brown. It refers to the dark brown colouration of the species.

Figures

Fig. 90-93: Osoriellus-s. str.-group: Osoriellus seriatus (90), O. majusculus (91), O. fumarius (92), O. caliginosus (93); antenna (A), protibia (B), aedeagus in lateral aspect (C); scale bar: 0.1 mm.