Osoriellus boliviensis, 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 : 260-261

Osoriellus boliviensis n. sp.

( Figs 68 A-C, 98D)

Type material: Holotype, male: Bolivia: Cochabamba, 67.5 km NE, Estacion Biol. Valle del Sajita (64°47.52'W, 17°06.33'S, Univ. de San Simon , 300 m elevation, male, 7.-9.Feb.1999, leg. F. Genier, #1Biol1G99041, collected by flight intercept trap ( KNHM).

Paratype: Peru: Huanuco, Sta. Panguana (74°56'W, 9°37'S), Rio Llullapichis , female, 11.-12.2008, leg. F. Wachtel ( UIC) .

Diagnosis: Concerning its size and absence of microsculpture on the pronotum, the species resembles O. minor and O. tuxtlae . It can be easily differentiated from these two species by the prominent eyes. Moreover, it differs from O. tuxtlae by the wider pronotum and elytra. The shape of the pronotum and the elytra are very similar to O. minor , but the pronotal punctation is distinctly sparser in O. boliviensis than in O. minor . In O. minor the interstices between the pronotal punctures are approximately as wide as the diameter of the punctures, whereas in O. boliviensis the interstices are nearly twice as wide as the diameter of the punctures.

Description: Length: 4.5 mm. Colouration: Brown; elytra lighter reddish; legs and antennae lighter brown.

Head: 0.57 mm long, 0.94 mm wide; eyes distinctly prominent and longer than temples; sides of fore-head narrowed to anterior angles in concave curve; sides of clypeus nearly parallel; apical margin even without granules at angles; setiferous punctation dense and deep with wide impunctate midline; interstices between punctures slightly smaller than half of diameter of punctures; on supraocular area punctation still denser, coriaceous and with granulate punctures; without microsculpture; surface shiny.

Antennae with flagellum as long as head and half of pronotum combined; with oblong second and conical third antennomere, both more or less quadrate; following antennomeres increasing in width, but all antennomeres more or less quadrate.

Pronotum: 0.93 mm long, 1.02 mm wide; widest at anterior angles; anterior angles not produced to teeth; smoothly convergent to posterior angles; posterior angles indistinct, obtuse; lateral margin in anterior half finer than in posterior half; in dorsal aspect, visible throughout its total length; setiferous punctation as deep, but sparser than on head; more or less equally dense on disc except wide impunctate midline; on average, distance between punctures approximately twice as wide as diameter of punctures; between normally coarse punctures with extremely fine micro-punctation; without microsculpture; surface polished and shiny.

Elytra: 0.98 mm long, 1.09 mm wide; with weak coriaceous ground-sculpture and weak setiferous punctation; punctures in irregular rows and hardly visible in ground sculpture.

Abdomen with dense and deep setiferous punctation; wide midline on tergite III to VIII impunctate; without or with weak remains of microsculpture; surface shiny, nearly polished.

Protibia: 0.50 mm long, 0.14 mm wide; slender; 8 long spines at outer edge; 3 apical spines inserted on short digits; WLR: 1.75; in posterior aspect, comb at inner emargination visible throughout its total length; posterior face with sparse setation.

Aedeagus with broad, slightly curved apical lobe; shortly narrowed in front of apex to obtuse apex.

Etymology: The specific name boliviensis refers to the country, where the species was collected.

Figures

Fig. 68-72: Osoriellus-s. str.-group: Osoriellus boliviensis (68), O. minor (69), O. rugipennis (70), O. triangulatus (71), O. franckei (72); antenna (A), protibia (B), aedeagus in lateral aspect (C); scale bar: 0.1 mm.