Osoriellus ashei, 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 : 258-259

Osoriellus ashei n. sp.

( Figs 57 A-C, 97B)

Type material: Holotype, male: Mexico: Veracruz, 2.5 km S. Jalapa (96°54'W, 19°29'N), 1370 m elevation, ex. Sifted from leaf litter, 26.5.1991, leg. J.S. Ashe ( KNHM).

Paratypes: Mexico: 2 males, 2 females with same data as holotype and 25.5.1991 ( KNHM); 3 km S. Jalapa, ex flight intercept trap, 1370 m elevation, 2 males, 26.5.1991, leg. J.S. Ashe ( KNHM, UIC) .

Diagnosis: Concerning the size and the punctation of the pronotum, the species is extremely similar to the species with irregular rows of the pronotal punctures, i.e. O. salvini , O. flaveolus , O. levyi , O. bicolor , and O. loksai . In particular, O. bicolor and O. loksai resemble O. ashei in the absence of the pronotal microsculpture and the smaller size than the other three species. Compared to O. bicolor and O. loksai , the pronotal punctation in O. ashei is denser and coarser. The aedeagi of the three species are also very similar, but the number of sensillae at the inner edge of the apical lobe is different.

Description: Length: 3.4 mm. Colouration: Reddish brown; front edge of head and legs reddish; antennae yellow.

Head: 0.48 mm long, 0.64 mm wide; eyes not prominent and as long as temples; fore-head narrowed in concave curve to front angles; anterior clypeal angles rectangular; setiferous punctation deep and irregularly dense; on average, interstices between punctures half as wide as diameter of punctures; on supraocular area and on midline impunctate or sparsely punctate; between setiferous punctures with micro-punctation; without microsculpture; surface polished and shiny.

Antennae as long as head and half of pronotum combined; second antennomere oblong and 1.5 times as long as conical third; antennomeres four to six as wide as or slightly wider than third; more or less quadrate; antennomeres seven to ten distinctly wider than preceding antennomeres and distinctly wider than long.

Pronotum: 0.65 mm long, 0.67 mm wide; widest at anterior angles; evenly convergent to obtusely rounded posterior angles; shape trapezoidal; lateral margin fine; in dorsal aspect, not visible close to anterior angles; setiferous punctures large and in irregular rows; within rows, interstices between punctures half as wide as diameter of punctures; between rows, interstices slightly wider; approximately 8 punctures per row; between setiferous punctures with sparse micro-punctation; without microsculpture; surface polished and shiny.

Elytra: 0.82 mm long, 0.69 mm wide; shoulders obtusely rounded; densely and coarsely punctate; setiferous punctation irregular on weakly coriaceous ground-sculpture; interstices between punctures half as wide as diameter of punctures; surface less shiny than on pronotum.

Abdomen with impunctate midline; on each side of midline with dense and deep setiferous punctation; interstices half as wide as diameter of punctures; surface polished and shiny.

Protibia: 0.40 mm long, 0.13 mm wide; with 8 spines at outer edge; apical spines inserted directly on outer edge; WLR: 6.7; in posterior aspect, comb at inner emargination covered in middle; posterior face covered by long and thick setae; setae at least half as long as protibial width.

Aedeagus with continuously curved apical lobe ending in obtusely rounded apex; inner edge of apical lobe with 8 sensillae.

Etymology: The species is named in honour of its collector, Prof. Dr. J.S. Ashe, who unfortunately passed too early.

Figures

Fig. 53-57: Osoriellus-s. str.-group: Osoriellus brevicornis (53), O. micros (54), O. surinamensis (55), O. grossopunctatus (55); Osoriellus ashei (57); antenna (A), protibia (B), aedeagus in lateral aspect (C); scale bar: 0.1 mm.