Osoriellus loreti, 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 : 301-302

Osoriellus loreti n. sp.

( Figs 116 A-C, 125C)

Type material: Holotype, male: Peru: Dept. Loreto, 1.5 km Teniente Lopez, (76°06.92'W, 2°36.66'S), 210-240 m elevation, collected from palmfruit by berlese method, 17.7.1993, leg. R. Leschen ( KNHM).

Paratypes: Peru: 4 females, 3 males with same data as holotype ( KNHM, UIC) ; 1 female from same location, but collected by berlese method at ridge top on 21.7.1993; Peru, Dept. Loreto, Campamento San Jacinto (75°51.77'W, 2°18.75'S), 175-215 m elevation, collected from flower fall by berlese method, 4 females, 2.7. and 10.7.1993, leg. R. Leschen ( KNHM) ; 1 female from same location, but collected by berlese method at Qd. 22 on 2.7.1993 ( KNHM) .

Diagnosis: Among the species with long digits at the outer edge of the protibia, O. loreti resembles O. lescheni in the size and shape of the pronotum. It is differentiated from that species by the weak pronotal microsculpture, the rectangular shoulders and the less long digits of the protibia. Furthermore, the shapes of the aedeagi are conspicuously different between the two species.

Description: Length: 4.2 mm. Colouration: Dark brown; elytra and posterior margin of pronotum lighter reddish brown; abdomen, legs and antennae still lighter yellowish brown.

Head: 0.52 mm long, 0.76 mm wide; eyes not prominent; as long as temples; sides of fore-head convergent to slightly prominent anterior angles in smooth concave curve; anterior edge very slightly sinuate; setiferous punctation weak and moderately dense; punctures at least partly granulate; narrow midline and small area at base of antennae impunctate; interstices between punctures at least twice as wide as diameter of punctures; yellow setae mostly shorter than interstices between punctures; few setae on supraocular area longer; isodiametric microsculpture extremely dense and deep; surface matt with iridescent shiny.

Antennae as long as head and half of pronotum combined; second antennomere oval and slightly longer than short conical third antennomere; antennomeres 4 to 6 approximately as wide as third, but quadrate; following antennomeres distinctly wider, but also approximately quadrate.

Pronotum: 0.80 mm long, 0.91 mm wide; widest in anterior third; slightly convergent to rectangular anterior angles; slightly more strongly convergent to posterior angles in smooth concave curve; posterior angles rounded, but nearly rectangular; posterior margin slightly emarginate; lateral margin thick; slightly widened to posterior angles; in dorsal aspect, visible throughout its total length; setiferous punctation much deeper and larger than on head; on average, interstices between punctures twice as wide as diameter of punctures; yellow setae nearly as long as interstices between punctures; between coarse punctures with sparse micro-punctation; impunctate midline wider in posterior half than in anterior half; isodiametric microsculpture much weaker and wider than on head; surface slightly shiny.

Elytra: 0.94 mm long, 0.87 mm wide; shoulders nearly rectangular; sides parallel; setiferous punctation as deep and dense as on pronotum; in irregular rows; coriaceous ground-sculpture deep; surface less shiny than on pronotum.

Abdomen with setiferous punctation weaker but much denser than on pronotum; netlike microsculpture weak; surface shiny.

Protibia: 0.43 mm long, 0.13 mm wide; on outer edge with 7 spines; apical spines inserted on moderately long digits; WLR: 1.00; in posterior aspect, inner emargination with comb visible throughout its total length; posterior face sparsely covered by long yellow setae.

Aedeagus symmetric with thick basal lobe and thin and slender apical lobe; in lateral aspect, apical lobe narrowed to acute apex in long smooth curve; apical lobe with lateral row of sensillae and group of three sensillae at base; inner edge of apical lobe with numerous sensillae.

Etymology: The specific name derived from the Peruvian Departamento Loreto, where the species was found.

Figures

Fig. 114-118: Remaining-species-group: Osoriellus neotropicus (114), O. lescheni (115), O. loreti (116), O. digitatus (117), O. opticus (118); antenna (A), protibia (B), aedeagus in ventral and lateral aspects (C); scale bar: 0.1 mm.