Osoriellus francke

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 : 268

Osoriellus francke i ( WENDELER, 1955) new combination ( Figs 72 A-C, 98A)

Osorius franckei WENDELER, 1955: 197

Type material examined: Brazil: Santa Catarina, Nova Teutonia (52°23'W, 27°11'S), male, leg. F. Plaumann (holotype in ZMHB) .

Further material examined:

Brazil: São Paulo, Teodoro Sampaio (52°10.15'W, 22°31.56'S), 2 females, August 1973, leg. F.H. Oliveira ( AMNH, UIC); Santa Catharina, Corupa (49°13'W, 26°26'S), Hansa Humboldt, female, Sept. 1948, leg. A. Maller ( AMNH) .

Diagnosis: Among the species of similar size and without pronotal microsculpture, O. franckei is characterised by the specific punctation of the pronotum. Compared to O. parumpunctatus , the pronotal punctation is denser, compared to O. tuxtlae and O. minor , the pronotal punctation is sparser. The aedeagus is charaterised by its strongly curved long apical lobe with only few sensillae on its inner edge.

Description: Length: 4.4 mm. Colouration: Black; elytra dark reddish-brown; legs and antennae reddish.

Head: 0.59 mm long, 0.90 mm wide; eyes not prominent; slightly longer than temples; sides of fore-head strongly narrowed in concave curve to anterior angles; front edge of clypeus even with short stout granules at angles; setiferous punctation on supraocular area coriaceous, on vertex coarse and dense, and on clypeus slightly sparser than on disc; wide midline impunctate; microsculpture weak, but dense; on supraocular area much denser and surface matter than on vertex; surface on vertex moderately shiny.

Antennae with oblong second antennomere; conical third antennomere as long as second; following three antennomeres approximately quadrate and as thick as preceding antennomeres; antennomeres 7 to 11 distinctly thicker than preceding antennomeres, but also approximately quadrate.

Pronotum: 0.88 mm long, 0.94 mm wide; widest at anterior angles; distinctly convergent to posterior angles in smooth curve; posterior angles smoothly rounded; lateral margin fine; in dorsal aspect, nearly invisible close to anterior angles; setiferous punctures much larger than on head; partly elongate and in irregular rows; row adjacent to impunctate midline consisting of 10 large punctures; on average, interstices between punctures of adjacent rows half as wide as diameter of punctures; distance between punctures within rows only one-fourth as wide as diameter of punctures; with weak netlike microsculpture and with sparse micro-punctation; surface shiny.

Elytra: 0.92 mm long, 0.95 mm wide; with weak coriaceous ground-sculpture; setiferous punctation in irregular rows; surface shiny.

Abdomen with dense setiferous punctation and impunctate midline; yellow setae pointing to midline; with weak netlike microsculpture; surface less shiny than on elytra and pronotum.

Protibia: 0.50 mm long, 0.15 mm wide; with 7 spines at outer edge; WLR: 1.6; in posterior aspect, comb of inner emargination totally visible; posterior face densely covered by yellow setae.

Aedeagus elongately curved; angulate in nearly rectangular angle.

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.