Osoriellus luteus, 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 : 276

Osoriellus luteus n. sp.

( Figs 46 A-C, 94D)

Type material: Holotype, male: Peru: Huánuco, Panguana (74°55.58'W, 9°36.55'S), forest, April/ May 1975, leg. W. Hanagarth ( UIC).

Paratypes: Peru: Huánuco, Panguana (74°55.58'W, 9°36.55'S), forest, female, Feb. 1975, leg. W. Hanagarth; river margin, female, 6.5.1976, leg. W. Hanagarth; clear cut forest, female, Jun.-Jul. 1975, leg. W. Hanagarth ( UIC) ; Brazil: Pará , 5 km E. Belém, soil litter layer in primary forest, male, 26.04.1976, leg. R.T. Schuh ( AMNH) ; French Guyana: Roura , 18.4 km SSE (52°13.25'W, 4°36.38'N), 240 m elevation, ex. flight intercept trap, male, 25.- 29.5.1997, leg. J.S. Ashe & R. Brooks, #FG1AB97 081 ( KNHM) .

Diagnosis: The species resembles O. exiguus and O. coruscus in size, but it can be easily differentiated from these species by the slightly prominent eyes. Concerning the shape of the head O. luteus resembles O. ocularis , but the eyes are less prominent and total size is smaller.

Description: Length: 2.8 mm. Colouration: Head brown; pronotum reddish; elytra and abdomen still lighter yellow; with darker spot in posterior half of elytra and on abdominal segments VI and VII.

Head: 0.33 mm long, 0.53 mm wide; with large and slightly prominent eyes; eyes as long as temples; area between eyes 9 times as wide as diameter of eyes; sides of fore-head sinuate and shortly convergent to anterior angles; anterior edge even; angles produced to short granules; setiferous punctures large and deep; punctation on vertex dense, but slightly finer and sparser than on clypeus; yellow setae pointing to middle; wide midline impunctate; with distinct netlike microsculpture; surface matt.

Antennae with first antennomere slightly longer than 2 following antennomeres combined; second antennomere globular; third antennomere conical and slightly shorter than second; the following 3 antennomeres quadrate and not wider than preceding antennomeres; last 5 antennomeres thicker and approximately quadrate.

Pronotum: 0.55 mm long, 0.60 mm wide; widest at anterior angles; slightly convergent to posterior angles; sides in anterior three-fourth nearly parallel; in front of posterior angles sinuate; lateral margin fine; in dorsal aspect, not visible in anterior half; setiferous punctation large and deep; moderately dense; along impunctate midline punctures in irregular rows; yellow setae pointing to middle; without microsculpture, but with extremely fine micro-punctation; surface polished and shiny.

Elytra: 0.65 mm long, 0.60 mm wide; with coriaceous ground-sculpture; setiferous punctation deep and large, but nearly invisible between ground-sculpture; yellow setae pointing to middle.

Abdomen deeply and densely punctate; setae pointing to middle.

Protibia: 0.35 mm long, 0.10 mm wide; 9 long spines at outer edge; WLR: 4.30; in posterior aspect, inner edge only slightly emarginate and comb partly covered in middle; posterior face with sparse setation.

Aedeagus with long and straight basal lobe and short smoothly curved apical lobe ending in acute apex.

Etymology: The specific name luteus derived from the same Latin word meaning yellow and refers to the yellow colouration of the elytra and the abdomen.

Figures

Fig. 43-47: Osoriellus-s. str.-group: O. exiguus (43), Osoriellus indescriptus (44), O. coruscus (45), O. luteus (46); O. punctatellus (47); antenna (A), protibia (B), aedeagus in lateral aspect (C); scale bar: 0.1 mm.