Osoriellus longipunctatus, 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 : 253

Osoriellus longipunctatus n. sp.

( Figs 38 A-C, 42A)

Type material: Holotype, male: Brazil: Pará, Ilha de Mosqueiro (48°22'W, 1°09'S), soil litter layer in primary forest, 20.6.1974, leg. R.T. Schuh ( AMNH).

Paratypes: Brazil: 5 males, 5 females with same data as holotype ( AMNH, UIC, INPA) ; Pará , Belém, IPEAN, primary terra firme forest, Plot #5, 3 females, 2 male, 6.6.1973, leg. R.T. Schuh ( AMNH, UIC) ; Belém , 2 males, 30.5.- 6.6.1973, leg. R.T. Schuh ( AMNH) .

Diagnosis: The species is characterised by the elongate punctures and the iridescent shine of the pronotum. It can be confused with O. guiananus concerning the size, the trapezoidal shape of the pronotum, and the digitate outer edge of the protibia. But the pronotal surface of O. guiananus is polished and shiny. A trapezeoidal shape of the pronotum is also found in O. breviceps , but O. breviceps is larger, the clypus is not emarginate and the posterior pronotal angles are obtuse and not nearly rectangular such as in O. longipunctatus .

Description: Length: 5.2 mm. Colouration: Dark brown; elytra, abdomen, legs, and antennae lighter brown.

Head: 0.65 mm long, 1.09 mm wide; eyes thick and prominent; twice as long as temples; sides of fore-head narrowed to acute anterior angles of clypeus in sinuate curve; on inner side of anterior angles with second short acute teeth; anterior edge emarginate; punctation dense; nearly coriaceous; punctures elongate; at least punctures of clypeus with very short yellow setae; on supraocular area punctation still denser and with striae; few punctures with long setae; pair of punctures on clypeus and on vertex close to neck with long setae; surface with weak and extremely dense microsculpture; surface with iridesence shine.

Antennae slightly longer than head; second antennomere oval, third conical and as long as second; antennomeres four to six nearly equally wide and quadrate; following antennomeres distinctly wider, but also nearly quadrate.

Pronotum: 1.06 mm long, 1.17 mm wide; widest at anterior angles; anterior angles very shortly produced to acute teeth; sides evenly narrowed to posterior angles; in front of posterior angles shortly emarginate; shape nearly trapezoidal; posterior angles still obtuse, but nearly rectangular; lateral margin fine in anterior half; thicker and widened to posterior angles; punctation dense and deep; punctures elongate; adjacent to midline, partly coriaceous; very narrow midline in posterior half and pair of small areas in posterior half impunctate; on average, interstices between punctures as wide as half of diameter of punctures or slightly wider; punctures without setae; between normal coarse punctures with sparse micro-punctation; surface with iridesence shine, but less distinct than on head.

Elytra: 1.28 mm long, 1.19 mm wide, sides nearly parallel; shoulders nearly rectangular; punctation indistinct; hardly visible in deep coriaceous ground-sculpture; punctures in irregular rows.

Abdomen with dense setiferous punctation; abdominal tergites III-VI with narrow impunctate midline; abdominal tergites VII and VIII with elongate punctures; without microsculpture; surface shiny.

Protibia: 0.52 mm long, 0.13 mm wide; outer edge with 7 spines; apical spines inserting on long teeth; WLR: 0.50; inner emargination with comb visible throughout its total length; posterior face sparsely covered by long yellow setae.

Aedeagus with thick apical lobe at base; then suddenly narrowed to shortly rounded apex; apical lobe laterally with six sensillae and at inner edge with row of numerous sensillae.

Etymology: The specific name longipunctatus is a combination of the epithet longus meaning long and punctatus meaning punctate and refers to the elongate punctation of the pronotum.

Figures

Fig. 38-40: Osoriellus-guiananus- and -mrazi-group:Osoriellus longipunctatus (38), Osoriellus silvaticus (39), O. mrazi (40); antenna (A), protibia (B), aedeagus in lateral aspect (C), clypeus (D); scale bar: 0.1 mm.