Osoriellus flaveolus, 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 : 267-268

Osoriellus flaveolus n. sp.

( Figs 50 A-C, 95C)

Type material: Holotype, male: Ecuador: Rio Napo, Limóncocha, 40 km E Puerto Francisco de Orellana / La Coca , 21.- 27.11.1979, leg. J. Balogh ( NHMH).

Diagnosis: The species resembles O. bicolor , O. levyi , and O. salvini . It can be differentiated from these three species by the iridescent shine of the head and the sparser and weaker punctation of the head and pronotum.

Description: Length: 3.7-3.8 mm. Colouration: Light brown; head and posterior margin of elytra darker brown; elytra, legs and antennae yellow.

Head: 0.48 mm long, 0.74 mm wide; eyes slightly prominent; sides of fore-head deeply emarginate; side of clypeus parallel; front edge of clypeus even and without lateral teeth, but with slight emargination; setiferous punctation sparse and fine; irregularly dense; wide impunctate midline; on average, interstices between punctures as wide as diameter of punctures; surface with iridescent shine.

Antennae slightly longer than head and half of pronotum combined; second antennomere oblong; conical third antennomere slightly shorter than second; follow- ing antennomeres slightly increasing in width; fourth and fifth antennomeres slightly longer than wide, sixth quadrate; seventh to tenth antennomeres wider than preceding antennomeres, but also quadrate.

Pronotum: 0.76 mm long, 0.80 mm wide; widest at anterior angles; slightly convergent to obtuse posterior angles in smooth curve; lateral margin fine; slightly thicker close to posterior angles than at anterior angles; in dorsal aspect, visible throughout its total length except close to anterior angles; setiferous punctation sparse, but slightly deeper than on head; with wide impunctate midline; on average, interstices between punctures as wide as or slightly wider than diameter of punctures; with dense micro-punctation and extremely weak remains of microsculpture; surface slightly shiny, but not polished.

Elytra: 0.89 mm long, 0.89 mm wide; with weak coriaceous ground-sculpture; setiferous punctation in irregular rows; distinctly visible; surface slightly shiny.

Abdomen with moderately dense setiferous punctation; without microsculpture; surface polished and shiny.

Protibia: 0.50 mm long, 0.13 mm wide; slender; with 9 spines at outer edge; apical spines inserted on short digits; WLR: 1.66; in posterior aspect, comb at inner emargination visible throughout its total length; setation of posterior face sparse.

Aedeagus with thick apical lobe ending in short acute apex; inner edge of apical lobe with 3 sensillae.

Etymology: The specific name derived from the same Latin word meaning yellow and refers to the light brown to dark yellow colouration and, in particular, to the yellow elytra.

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.