Osoriellus sexpunctatus ( BERNHAUER, 1912 ) 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 : 307

Osoriellus sexpunctatus ( BERNHAUER, 1912) new combination

( Figs 113 A-C, 124A)

Osorius sexpunctatus BERNHAUER, 1912: 168

Type material examined: Argentina: Buenos Aires, female, leg. Richter (holotype in FMNH)

Further material examined: Argentina: La Plata, Rio Santiago, 5 specimens, 5.10.1919, leg. J. Weiser ( NHMP, UIC) .

Diagnosis: O. sexpunctatus is distinctly characterised by the large size and the sparse pronotal punctation. The species resembles O. neotropicus in the shape and punctation of the pronotum. It can be distinguished from that species by the teeth-like produced anterior angles of the pronotum, the more distinct microsculpture and the smaller eyes.

Description: Length: 7.8 mm. Colouration: Black; elytra and legs brown.

Head: 1.30 mm long, 1.50 mm wide; eyes small, only half as long as temples; anterior angels of clypeus granulate; punctation deep, but sparse; interstices between punctures irregular; on average, twice as wide as diameter of punctures; wide midline impunctate; yellow setae pointing to middle; two long supraocular setae and several long setae closer to middle; netlike microsculpture weak; surface slightly shiny.

Antennae with first antennomere as long as following 3 antennomeres; second antennomere oval and as long as conical third; antennomeres 4 to 6 approximately quadrate; following 4 antennomeres much thicker and wider than long.

Pronotum: 1.40 mm long, 1.65 mm wide; widest at anterior edge; anterior angles produced to hook-like teeth; sides evenly convergent to posterior angles; posterior edge two-third as wide as anterior edge; lateral margin extremely fine; several long setae at anterior angles and another seta in middle; along lateral margin with row of short yellow setae; punctation sparse; along wide impunctate midline row of 6 punctures; weak microsculpture netlike; surface slightly shiny.

Elytra: 1.70 mm long, 1.60 mm wide; with deep coriaceous ground-sculpture and slightly visible large punctures; surface slightly shiny.

Abdomen more densely punctate than pronotum except on wide impunctate midline; on impunctate midline of each abdominal segment several transverse striae.

Protibia: 0.85 mm long, 0.27 mm wide; 8 spines on outer edge; apical 3 spines inserted on long digits; WLR: 0.51; in posterior aspect, comb at inner edge of emargination visible throughout its total length.

Aedeagus with broad apical lobe ending in acute apex; upper edge of apical lobe sinuate; with lateral group of sensillae and row of sensillae on inner edge of apical lobe.

Figures

Fig. 109-113: Remaining-species-group: Osoriellus cordovensis (109), O. germanus (110), O. notmani (111), O. opacinotus (112), O. sexpunctatus (113); antenna (A), protibia (B), aedeagus in ventral and lateral aspects (C); scale bar: 0.1 mm.