Osoriellus loksai, 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 : 275-276

Osoriellus loksai n. sp.

( Figs 59 A-C, 96E)

Type material: Holotype, male: Paraguay: Puerto Presidente Stroessner , Soil-Zool. Exp., 26.12.1965, leg. I. Loksa ( NHMH).

Paratypes: Paraguay: 1 female with same data as holotype; Puerto Presidente Stroessner, Acaray water fall, Soil-Zool. Exp. , female, 2.1.1966, leg. I. Loksa; Puerto Presidente Stroessner, Soil-Zool. Exp. , female, 26.- 29.12.1965, leg. J. Balogh , female, 5.1.1966, leg. J. Balogh & L.S. Mahunka; Brazil: Paraná, Hungarian Soil-Zool.Exp., female, Foz do Iguazu, Iguazu Waterfalls , 2 females, 29.12.1965, leg. J. Loksa ( NHMH, UIC); Santa Catarina , Linha Facão, 2 males, May 1954, leg. F. Plaumann ( KNHM) .

Diagnosis: The species resembles O. bicolor , O. levyi , O. salvini , and O. flaveolus . It is slightly smaller than O. salvini and O. flaveolus . According to the pronotal punctation it is intermediate between O. levyi and O. bicolor . The punctation is slightly denser than in O. levyi , but sparser and less deep than in O. bicolor . The three species can be differentiated mainly be the shape of the apical lobe of the aedeagus. In O. levyi the apical lobe is ending in an acute apex, whereas it is ending in an obtuse apex in O. bicolor and O. loksai .

Description: Length: 3.3 – 3.4 mm. Colouration: Reddish; posterior margin of pronotum and suture of elytra lighter reddish; legs and antennae yellow.

Head: 0.46 mm long, 0.65 mm wide; eyes small and not prominent; temples nearly 1.5 times as long as eyes; sides of fore-head moderately sinuate; sides of clypeus parallel; front edge of clypeus even without lateral teeth; setiferous punctation moderately deep and dense, but with large area at base of antennae and wide midline impunctate; on vertex, interstices between punctures shorter than half of diameter of punctures; partly coriaceous, in particular, on supraocular area; without microsculpture; surface polished and shiny.

Antennae as long as head and half of pronotum combined; second antennomere oblong; thicker and longer than conical third antennomere; fourth to sixth antennomeres not wider than third, but quadrate or shortly wider than long; seventh to tenth antennomeres thicker than preceding antennomeres; penultimate antennomere nearly twice as wide as long.

Pronotum: 0.64 mm long, 0.64 mm wide; widest at anterior angles; slightly and evenly narrowed to posterior angles; in posterior third more distinctly convergent than in anterior two-third; posterior angles widely rounded; lateral margin extremely fine, but visible throughout its total length; setiferous punctation moderately dense and deep; in irregular rows; interstices between punctures within rows half as wide as diameter of puncture; interstices between adjacent rows as wide as diameter of punctures; with wide midline impunctate; moderately dense micro-punctation; remains of weak microsculpture; surface nearly polished and shiny.

Elytra: 0.69 mm long, 0.65 mm wide; weak coriaceous ground-sculpture; setiferous punctation in irregular rows; punctures distinctly visible within ground-sculpture; surface shiny.

Abdomen with dense setiferous punctation and wide impunctate midline on tergites; without microsculpture; surface polished and shiny.

Protibia: 0.40 mm long, 0.14 mm wide; 9 spines on outer edge; apical 2 spines on short digits; WLR: 2.60; in posterior aspect, comb at inner emargination visible throughout its total length; posterior face with moderately dense setation.

Aedeagus with long and slender apical lobe ending in obtuse apex; at inner edge of apical lobe with 4 sensillae.

Etymology: The species is named in honour of its collector Dr. I. Loksa.

Figures

Fig. 58-62: Osoriellus-s. str.-group: Osoriellus levyi (58), O. loksai (59), O. bicolor (60), O. salvini (61), O. eggersi (62); antenna (A), protibia (B), aedeagus in lateral aspect (C); scale bar: 0.1 mm.