Osoriellus latitibialis, 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 : 273-274

Osoriellus latitibialis n. sp.

( Figs 52 A-C, 95A)

Type material: Holotype, male: Napo, 81 km NE of Baeza, 3 km SW Reventador (77°41'W, 0°06'S), 1750 m elevation, sampled from litter, 28./ 29.10.1988, leg. L. Herman ( AMNH).

Paratype: Ecuador: 69 km NE of Baeza, 15 km SW of Reventador (77°44'W, 0°09'S), 1500 m elevation, sampled from foliage, female, 28.- 30.10.1988, leg. L. Herman ( UIC) .

Diagnosis: O. latitibialis is characterised by the typical shape of the protibia. It slightly resembles O. eggersi and O. carinicollis in size and dense pronotal punctation. But the shape of the pronotum is more parallel than in these two species with a trapezoidal pronotal shape.

Description: Length: 3.6 – 3.7 mm. Colouration: Black; legs and antennae reddish; anterior margin of clypeus yellow.

Head: 0.47 mm long, 0.65 mm wide; eyes as long as temples; not prominent; sides of fore-head emarginate; anterior margin even; on supraocular area, setiferous punctation dense and distinct; fore-head and clypeus very sparsely punctate; on clypeus interstices between punctures as wide as diameter of punctures; on vertex much denser; interstices between punctures less than one-fourth of diameter of punctures; setae yellow and extremely long; on vertex with narrow impunctate midline; on densely punctate supraocular area with remains of microsculpture; on central vertex and forehead without microsculpture; surface polished and shiny.

Antennae with oval second antennomere and conical third antennomere; third antennomere slightly shorter than second; antennomeres 4 to 6 quadrate and not wider than preceding antennomeres; following antennomeres slightly thicker than preceding antennomeres; approximately quadrate.

Pronotum: 0.64 mm long, 0.71 mm wide; widest at anterior angles; sides in anterior two-third nearly parallel; in posterior third, smoothly narrowed in convex curve to obtuse posterior angles; lateral margin narrow; in dorsal aspect, only visible in posterior third; setiferous punctures dense and deep; nearly coriaceous; interstices between punctures less than one-fourth of diameter of punctures; narrow midline impunctate; yellow setae extremely long; without microsculpture; based on dense punctation surface matt.

Elytra: 0.75 mm long, 0.70 mm wide; with setiferous punctation; punctation nearly coriaceous; yellow setae extremely long; surface without microsculpture; based on dense punctation matt.

Abdomen with dense setiferous punctation, but slightly less dense than on elytra.

Protibia: 0.50 mm long, 0.17 mm wide; asymmetric; widest in apical third; on outer edge with 8 slender and short spines; WLR: 2.50; in posterior aspect, comb of inner emargination partly covered in apical third; posterior face covered by very long yellow setae; setae longer than half of protibial width.

Aedeagus with long, smoothly rounded apical lobe; apex acute.

Etymology: The specific name is a combination of the epithet latus meaning broad and tibia. It refers to the specific shape of the front leg.

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.