Osoriellus sinuatus, 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 : 243

Osoriellus sinuatus n. sp.

( Figs 19 A-C, 20E)

Type material: Holotype, male: Ecuador: Napo Prov. Sacha Lodge (76°27.32"W, 0°28.15'S), 250 mm elevation, 26.- 28.10.2004, leg. G. de Rougemont ( UIC).

Paratypes: Ecuador: 1 male with same data as for holotype ( UIC) ; Sucumbios Prov. Sacha Lodge (76°5'W, 0°5'S), 270 m elevation, collected by Malaise trap, 4 females, 2 males, 13.- 25.7.1994, 25.7.- 3.8.1994, 3.- 16.8.1994, 3.- 13.7.1994, leg. Hibbs ( KNHM) ; same location (76°27'35"W, 0°28'14"S), but flight intercept trap, 270 m elevation, male, 21.- 24.5.1999, leg. R. Brooks ( KNHM) ; Napo, Tena , 500 m elevation, 2.3.1987, leg. K.A. Johnson ( KNHM) ; Jatun Sacha Biol. Stat. (21 km E Puerto Napo, lowland rainforest, flight intercept trap, female, 18.7.1994, leg. Levy & Genier ( KNHM) ; Prov . Napo, Tiputini Res. Stat. (76°09'W, 0°38'S), flight intercept trap, 220 m elevation, 2 males, 1 female, 5.- 25.09.2000, leg. D.J. Inward & K.A. Jackson ( BMNH) ; Peru: Madre de Dios, Iberia , 500 ft elevation, male, 30.4.1947, leg. J.C. Pallister ( AMNH) .

Diagnosis: The species can be easily differentiated from all other Neotropical Osoriellus species by the deeply emarginate sides of the pronotum and the clypeal angles. produced to long acute teeth. In contrast to O. sinuatoangularis and O. subsinuatus , the emargination in front of the posterior angles is margined.

Description: Length: 4.8 mm. Colouration: Black; elytra dark red; legs and antennae brown.

Head: 0.60 mm long, 0.91 mm wide; eyes slightly prominent; sides of fore-head concavely narrowed to front angles; sides of clypeus parallel; front angles of clypeus produced to long teeth; anterior edge between lateral teeth even; setiferous punctation distinct, but weak and moderately dense; area at base of antennae and narrow midline impunctate; supraocular area more coarsely punctate than on vertex; on vertex, interstices between punctures on average as wide as diameter of punctures; netlike microsculpture distinct; surface slightly shiny.

Antennae slightly shorter than head and half of pronotum combined; second antennomere oblong; longer than wide; third conical antennomere not longer than wide; following antennomeres more or less quadrate; antennomere 4 and 5 not wider than preceding antennomeres; last 5 antennomeres distinctly thicker than preceding antennomeres, but quadrate.

Pronotum: 0.88 mm long, 0.95 mm wide; widest at anterior angles; anterior angles produced to short acute teeth; sides in anterior half nearly parallel; in posterior half slightly stronger convergent; deeply emarginate in front of posterior angles; lateral margin visible throughout its total length; setiferous punctation moderately dense and punctures much larger than on head; on average, interstices between punctures slightly shorter than diameter of punctures; wide midline impunctate; netlike microsculpture deep and partly isodiametric near anterior edge; surface slightly shiny.

Elytra: 1.08 mm long, 1.09 mm wide; with weak, but dense ground-sculpture; irregular rows of setiferous punctures distinctly visible.

Abdomen with dense setiferous punctation; microsculpture weak; on posterior tergites weaker than on anterior tergites; surface on posterior tergites polished and shiny. Protibia: 0.57 mm long, 0.18 mm wide; nearly semicircular; with 9 spines on outer edge; apical spines not inserted on digits; WLR: 3.5; in posterior aspect, comb at inner emargination partly covered; posterior face covered by long yellow setae.

Aedeagus with long abruptly curved apical lobe ending in obtuse broad apex; on inner edge with row of sensillae.

Etymology: The specific name derived from the same Latin word meaning emarginate and refers to the emarginate sides of the pronotum.

Figures

Fig. 16–19: Osoriellus-bicornis-group: Osoriellus sinuatoangularis (16), O. subsinuatus (17), O. corniculatus (18), O. sinuatus (19); antenna (A), protibia (B), aedeagus in lateral aspect (C), anterior edge of clypeus (D); scale bar: 0.1 mm.