Osoriellus setosus, 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 : 247-248

Osoriellus setosus n. sp.

( Figs 22B, C , 27E )

Type material: Holotype, male: Ecuador: Napo, 81 km NE Baeza, 3 km SW Reventador, 5300 ft elevation, litter, 28., 29.10.1988, leg. L. Herman ( AMNH).

Paratypes: Ecuador: Napo Prov. 5 km S. Baeza, on Road to Tena , 1700 m elevation, under rocks and logs, 2 males, 28.4.1990, leg. C. Carlton & R. Adrave ( KNHM) ; Napo Prov. 81 km NE Baeza, 3 km SW Reventador , 5300 ft elevation, litter, 2 males, 2 females, 28., 29.10.1988, leg. L. Herman ( AMNH, UIC) ; Prov . Napo, Cosanga (77°51.52'W, 0°34.45'S), 1950 m elevation, beating of forest vegetation, female, 25.11.2009, leg. L. Sekerka & K. Stajerova ( BMNH) .

Diagnosis: Among the O.- hirtulus -group, O. setosus can be easily identified by the symmetric aedeagus, similar as in O. setifer . The species is larger than O. setulosus and O. pubicollis , but smaller than O. hirtulus . Compared to O. pubicollis , the pronotum is more triangular. It resembles O. pubescens in shape and size. However, the aedeagus of O. pubescens is asymmetric like in O. setulosus and O. pubicollis .

Description: Length: 6.6 mm. Colouration: Brown; pronotum and abdominal segments III-VI lighter brown; legs and antennae light brown.

Head: 1.11 mm long, 1.44 mm wide; eyes moderately large; not prominent; as long as temples; sides of fore-head emarginate; anterior edge of clypeus even; setiferous punctation irregularly dense; on fore-head sparser than close to neck; close to neck, interstices between punctures one fourth as wide as diameter of punctures; small area on central posterior vertex and at base of antennae impunctate; on supraocular area punctures partly granulate; netlike microsculpture weak; surface shiny.

Antennae slightly longer than head; second antennomere globular; as long as third; following antennomeres approximately quadrate.

Pronotum: 1.36 mm long, 1.55 mm wide; widest at anterior angles; evenly convergent to widely rounded posterior angles; anterior angles produced to short acute teeth; lateral margin fine; finer at anterior angles than at posterior angles; setiferous punctation deep and dense; interstices between punctures half as wide as diameter of punctures; moderately wide midline impunctate; without microsculpture; surface shiny.

Protibia: 0.81 mm long, 0.24 mm wide; 8 spines at outer edge; apical four spines inserted on short teeth; WLR: 0.7; in posterior aspect, comb of inner emargination visible throughout its total length; posterior face with moderately dense setation; on average, setae slightly longer than half of protibial width.

Aedeagus symmetric; apical lobe triangular; smoothly curved to acute angle.

Etymology: The specific name refers to the dense setiferous punctation of the total body.

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.