Osoriellus seriatus, 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 : 286-287

Osoriellus seriatus n. sp.

( Figs 90 A-C, 100E)

Type material: Holotype, male: Peru: Tambopata Prov. Madre de Dios Depto., 15 km NE Puerto Maldonado, Reserva Cuzco Amazónico (69°03'W, 12°33'S), 200 m elevation, collected by flight intercept trap by Plot #Z2E17, 20.6.1989, leg. J.S. Ashe & R.A. Leschen, ( KNHM).

Paratypes: Peru: male with same data as holotype, but 17.7.1989 by flight intercept trap at swamp trail ( UIC) .

Diagnosis: Among the similarly sized species of the O.-s. str.-group with non-digitate protibia, O. seriatus resembles O. debilis in the size and punctation of the head and pronotum. In contrast to O. debilis , the lateral pronotal margin is slightly wider at the posterior angles, whereas in O. debilis the width is equal throughout the total length. Furthermore, the pronotal sides are more curved than in O. debilis . The aedeagus in O. seriatus is angulate, but evenly curved in O. debilis .

Description: Length: 5.4 long. Colouration: Black; legs and antennae reddish brown.

Head: 0.74 mm long, 1.13 mm wide; eyes slightly prominent; as long as temples; fore-head convergent to anterior angles in deep sinuate curve; anterior edge slightly emarginate; setiferous punctation moderately deep and dense; narrow midline, area at base of antennae, and transverse oval area close to neck impunctate; on clypeus, interstices between punctures wider than diameter of punctures; on vertex, interstices between punctures shorter than diameter of punctures; small supraocular area with dense coriaceous and partly granulate punctation; isodiametric microsculpture dense and moderately deep; surface slightly shiny.

Antennae slightly shorter than head and half of pronotum combined; second antennomere oval and as long as conical third; following three antennomeres slightly increasing in width; antennomeres 4 and 5 approximately quadrate; sixth antennomere slightly wider than long; following antennomeres distinctly wider than preceding antennomeres, but approximately quadrate.

Pronotum: 1.16 mm long, 1.31 mm wide; widest shortly behind anterior angles; convergent to posterior angles in smooth curve; posterior angles obtuse and shortly rounded; lateral margin fine; finer near anterior angles than at posterior angles; shortly and slightly widened near posterior angles; setiferous punctation deep and moderately dense; adjacent to wide impunctate midline in dense row; posteriad sparser; on average, interstices between punctures wider than diameter of punctures; between normal deep punctures with fine and sparse micro-punctation; isodiametric microsculpture dense and moderately deep; surface slightly shiny.

Elytra: 1.42 mm long, 1.27 mm wide; shoulders shortly rounded in nearly rectangular angle; sides nearly parallel; setiferous punctation finer than on pronotum and in irregular rows; coriaceous ground-sculpture deep; surface slightly shiny.

Abdomen with dense setiferous punctation; netlike microsculpture weak; surface slightly shiny.

Protibia: 0.65 mm long; 0.22 mm wide; 8 spines at outer edge; apical spines inserted on short broad teeth; WLR: 1.77; in posterior aspect, comb of inner emargination covered in middle; posterior face densely covered by long yellow setae.

Aedaegus acutely angulate; apical lobe and basal lobe thick and equally long; apical lobe evenly narrowed to obtuse apex; inner edge of apical lobe with 4 sensillae.

Etymology: The specific name seriatus derived from the same Latin word meaning in rows and refers to the punctation of pronotum and elytra.

Figures

Fig. 90-93: Osoriellus-s. str.-group: Osoriellus seriatus (90), O. majusculus (91), O. fumarius (92), O. caliginosus (93); antenna (A), protibia (B), aedeagus in lateral aspect (C); scale bar: 0.1 mm.