Osoriellus schubarti, 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 : 235-236

Osoriellus schubarti n. sp.

( Figs 4A – D , 5C )

Type material: Holotype, male: Brazil: Est. Rio de Janeiro, Petropolis (43°11'W, 22°30'S), Alto da Serra , male, 10.09.1961; leg. H. Schubart ( INPA).

Paratype: Petropolis , Meio da Serra, male, 15.8.1960, leg. H. Schubart ( UIC) .

Diagnosis: Together with O. laeviusculus , the species has a specific combination of characters. It has no setiferous punctation and the aedeagus is symmetric with both sides of apical lobe sclerotised. Concerning the lateral margin of the pronotum and the absent spines on the posterior face of the protibia the species must be placed to the genus Osoriellus . The species resembles O. laeviusculus in the absence of the setiferous punctation, but the punctation is finer and sparser and the anterior edge of the clypeus is crenate, whereas it is even in O. laeviusculus . Furthermore, the microsculpture of the pronotum in O. schubarti is netlike, but longitudinal in O. laeviusculus . A crenate anterior edge and a symmetric aedeagus are also found in the O.- oculatus -group, but these species have a setiferous punctation.

Description: Length: 5.2 mm. Colouration: Black; posterior angles and suture of elytra reddish; legs and antennae red.

Head: 0.70 mm long, 1.10 mm wide; eyes slightly prominent and slightly longer than temples; sides of clypeus evenly convergent to front angles; crenate edge truncate with outer angles produced to short teeth; punctation fine and moderately sparse; on average, interstices between punctures as wide as or slightly wider than diameter of punctures; on supraocular space, punctures elongate or striate; few supraocular punctures with setae; two setiferous punctures on each side of middle on line between front edge and posterior edge of eyes; with dense longitudinal microsculpture; surface matt.

Antennae slightly longer than head; second antennomere oblong; conical third antennomere as long as second; following three antennomeres as wide as preceding antennomeres; more or less quadrate; antennomeres 7 to 11 thicker than preceding antennomeres, but also quadrate.

Pronotum: 1.06 mm long, 1.20 mm wide; widest at anterior angles; evenly convergent to widely rounded posterior angles; lateral margin fine; in dorsal aspect, visible throughout its total length; punctation fine and sparse; still finer and sparser than on head; distance between punctures at least two times wider than diameter of punctures; indistinct impunctate midline; few setiferous punctures along anterior and lateral margin

Key to the species

1 Longer than 5.0 mm, anterior edge of clypeus crenate and pronotum with netlike microsculpture. .............. ......................................................... O. schubarti n. sp.

- Smaller than 5.0 mm, anterior edge of clypeus even and pronotum with longitudinal microsculpture. ................ ................................. O. laeviusculus ( BERNHAUER, 1920) and two setiferous punctures on lateral third; netlike microsculpture distinct; less dense than on head; thus, surface slightly shiny.

Elytra: 1.28 mm long, 1.24 mm wide; with weak coriaceous ground sculpture; punctation fine and sparse, but punctures larger than on pronotum; surface shiny.

Abdomen with sparse and fine punctation; on segment VII with deeper and larger punctation than on preceding segments; without microsculpture; surface polished and shiny.

Protibia: 0.65 mm long, 0.17 mm wide; outer edge with 7 long spines; apical spines on moderately long digits; WLR: 0.83; in posterior aspect, comb at inner emargination visible throughout its total length; posterior face sparsely covered by long setae.

Aedeagus symmetric; with beak-like apical lobe ending in acute apex.

Etymology: The specific name derived from the collector of the species, Prof. H. Schubart.

Figures

Fig. 2-4: Osoriellus-coronatus- and –laeviusculus-group: Osoriellus coronatus (2), O. laeviusculus(3), O. schubarti (4); antenna (A), protibia (B), aedeagus in lateral aspect (C), anterior edge of clypeus (D), abdominal segment VII (E); scale bar: 0.1 mm.

Fig. 5: Osoriellus-coronatus- and –laeviusculus-group: Head, pronotum and elytra of Osoriellus coronatus (A); O. laeviusculus(B), O. schubarti (C); scale bar: 0.5 mm.