Osoriellus sticticus, 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 : 307-308

Osoriellus sticticus n. sp.

( Figs 105 A-C, 126B)

Type material: Holotype, male: Bolivia: Cochabamba, 67.5 km NE Est. Biol. Valle de Sajita, Univ. de San Simon (64°47.52'W, 17°06.33'S), 300 m elevation, collected by flight intercept trap, 7.- 9.2.1999, leg. F. Genier ( KNHM), #1BOL1G99041.

Paratypes: Bolivia: Cochabamba, Cochabamba, 109 km E Yungas (Cochabamba – Villa Tunari Rd.) (65°42.54'W, 17°08.52'S), 1400 m elevation, collected by flight intercept trap, male, 8.- 12.2.1999, leg. F. Genier ( KNHM), # BOL1 G99060; Cochabamba, Cochabamba 109 km E Yungas (Cochabamba – Villa Tunari Rd.) (65°42.29'W, 17°08.50'S), 1480 m elevation, collected by flight intercept trap, male, 1.- 6.2.1999, leg. F. Genier ( KNHM), # BOL1 G99027; Santa Cruz, Amboro National Park , Los Volcanes (63°36'W, 18°06'S), 1000 m elevation, collected by flight interecept trap, male, 20.11.- 12.12.2004, leg. H. Mendel & M.V.L. Barcley ( BMNH) ; Peru: Hunanuco, Panguana (74°56'W, 9°37'S), rainforest, collected by pitfall trap, Aug.-Sept. 1975, male, leg. W. Hanagarth ( UIC) .

Diagnosis: The species is characterised by its large size, the polished surface of the pronotum and the dense pronotal micro-punctation. The lateral margin of the pronotum is evenly convergent to the posterior angles in a smooth curve. Therefore, the posterior angles are obtuse without forming distinct angles.

Description: Length: 6.4 mm. Colouration: Black; legs and antennae brown.

Head: 0.92 mm long, 1.35 mm wide; eyes slightly prominent, longer than temples; fore-head convergent to anterior edge of clypeus in slight and even concave curve; sides close to anterior angles of clypeus parallel; anterior angles of clypeus shortly produced to acute teeth; anterior edge between teeth even; setiferous punctation irregular; on clypeus slightly sparser than on vertex; large transverse oval area on vertex and area at base of antennae impunctate; short midline on anterior vertex impunctate; setae moderately long; lateral punctures of vertex and on supraocular area granulate; netlike microsculpture distinct; surface moderately matt.

Antennae slightly longer than head; second antennomere oval; slightly longer than wide; third conical and as long as second; fourth antennomere conical and as wide as third, but shorter; antennomeres 5 and 6 quadrate and as wide as preceding antennomeres; following antennomeres wider than preceding antennomeres and approximately quadrate.

Pronotum: 1.21 mm long, 1.40 mm wide; widest at obtuse anterior angles; sides evenly convergent to posterior angles; posterior angles obtuse; in front of posterior angles shortly and slightly emarginate; lateral margin fine; slightly widened in front of posterior angles; setiferous punctation deep and moderately dense; setae extremely short; shorter than diameter of punctures; on average, interstices between punctures twice as wide as diameter of punctures; line of punctures adjacent to impunctate midline denser; partly coriaceous; netlike microsculpture moderately deep; surface moderately matt.

Elytra: 1.53 mm long, 1.40 mm wide; widest in posterior third, but sides nearly parallel; setiferous punctation as deep and dense as on pronotum, but hardly visible in deep coriaceous ground-sculpture; surface matt.

Abdomen with dense setiferous punctation; setae longer than on fore-body; punctures on abdominal tergites VII and VIII partly granulate and striate.

Protibia: 0.86 mm long, 0.29 mm wide; 10 spines on outer edge; 4 apical spines inserted on moderately long digits; WLR: 0.73; in posterior aspect, inner emargination with comb visible throughout its total length; posterior face densely covered by long yellow setae.

Aedaegus rectangularly angulate; apical lobe long with straight inner edge; apex of apical lobe moderately acute and slightly curved; inner edge of apical lobe with numerous sensillae.

Etymology: The specific name derived from the same Latin word meaning punctate and refers to the dense punctation of the abdomen.

Figures

Fig. 103-108: Remaining-species-group: Osoriellustrinitatis (103), O. carinicollis (104), O. sticticus (105), O. acutus (106), O. orbiculatus (107), O. adustus (108); antenna (A), protibia (B), aedeagus in lateral aspect (C); scale bar: 0.1 mm.