Osoriellus guiananus ( BERNHAUER, 1934 ) 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 : 252-253

Osoriellus guiananus ( BERNHAUER, 1934) new combination

( Figs 32 A-C, 41A)

Osorius guiananus BERNHAUER, 1934: 157

Type material examined: Guyana: Essequibo River , Moravalli Creek (58°38'W, 6°24'N), female, 30.8.1929, leg. Oxford Univ. Expedition (holotype in FMNH) .

Further material examined: Guyana: Essequibo River, Moraballi Creek (58°38'W, 6°24'N), female, 9.9.1929, leg. Oxford Univ. Expedition ( BMNH) ; French Guyana: Coralie (52°21.38'W, 4°30.41'N), male, 15.11.2011, leg. T. Struyve ( UIC) ; Suriname: Marowijne, Palumenu (55°26.18'W, 3°20.56'N), 160 m elevation, collected by flight intercept trap, female, 5.- 9.7.1999, leg. Z.H. Falin & D. Konoe, SUR1F99 185 ( KNHM) .

Diagnosis: O. guiananus closely resembles O. longipunctatus and O. breviceps in the shape and punctation of the pronotum and the rectangular shoulders of the elytra. O. breviceps is distinctly larger and the digits on outer edge of protibia shorter. Compared to O. longipunctatus , the colouration is black, whereas it is light brown in O. longipunctatus . The pronotal punctures are not elongate and the surface is without microsculpture and without iridescent shine.

Description: Length: 5.3 mm. Colouration: black, posterior edge of pronotum reddish, elytra dark red, antennae and legs lighter red.

Head: 0.65 mm long, 1.00 wide; front margin of clypeus with wide emargination and without teeth at outer angles; eyes as long as temples; with dense punctation, except moderately wide midline and large area at base of antennae; distance between punctures much shorter than diameter of punctures; each puncture with short yellow seta; without microsculpture, surface polished and shiny. Antennae with first antennomere as long as three following antennomeres, second antennomere globular, third shorter than second, antennomeres 4 to 6 increasing in width, sixth wider than long; antennomeres 7 to 10 distinctly larger than preceding antennomeres and wider than long. Pronotum: 0.90 mm long, 1.00 mm wide; widest at anterior edge; evenly convergent to posterior edge; lateral and posterior margin narrow; punctation conspicuously sparser than on head; interstices between punctures as wide as diameter of punctures; wide midline impunctate; each puncture with short yellow seta pointing posteriad and partly curved; sparse micro-punctation between coarse punctation; surface polished and shiny.

Elytra: 1.00 mm long, 1.00 mm wide; with coriaceous ground-sculpture, large dense punctation hardly visible in deep ground-sculpture; each puncture with short yellow seta pointing posteriad; surface less shiny than on pronotum.

Abdomen with dense punctation; each puncture with long yellow seta; surface polished.

Protibia: 0.59 mm long, 0.14 mm wide; with 7 spines, apical 5 spines inserted on moderately long digits; WLR: 0.57; in posterior aspect, comb of inner emargination totally visible; on anterior face with row of 7 long setae; posterior face sparsely covered by long yellow setae.

Aedeagus angulate in nearly rectangular angle; apical lobe thick at base; then suddenly narrowed to nearly acute apex; apical lobe laterally and apically with groups of three sensillae and at inner edge with row of numerous sensillae.

Figures

Fig. 32-37: Osoriellus-guiananus-group: Osoriellus guiananus (32), O. breviceps (33), O. solidus (34), O. macrops (35), O. melancholicus (36), O. diversus (37); antenna (A), protibia (B), aedeagus in lateral aspect (C); scale bar: 0.1 mm.