Bironium striatum, Löbl, 2021

Löbl, Ivan, 2021, A review of the Bironium Csiki, 1909 (Coleoptera: Staphylinidae: Scaphidiinae) of New Guinea and the Moluccas, Acta Musei Moraviae 106 (2), pp. 227-248 : 244-245

Bironium striatum sp. nov.

( Figs 46 -49)

Type material. Holotype ♂, IRIAN JAYA Jayapura Prov., leg. A. Riedel / Lereh 300- 550 m, 25.I.1996 / from base of dead palm leaves ( MHNG) . Paratypes 6 ♀, with the same data as the holotype ( MHNG).

Description. Length 2.20- 2.35 mm, width 1.32- 1.35 mm. Head, thorax and elytra dark reddish­brown to blackish, abdomen lighter than thorax, appendages ochraceous to yellowish. Pronotum very finely punctate. Scutellum triangulate. Elytra lacking humeral humps; adsutural areas flat or slightly raised; sutural and lateral striae punctate; basal striae entire, joined to lateral striae; discal punctation sparse, irregular, to part similar to pronotal punctation, very shallow and hardly visible at 100 times magnification, most punctures much larger than pronotal punctures, well visible at 15 times magnification. Mesoventrite slightly convex, with well delimited mesal ridge extended from paxillum to apical margin, impunctate, lacking microsculpture, with conspicuous longitudinal to oblique striae on mesocoxal process. Metaventrite not microsculptured, entirely very finely punctate. Median part of metaventrite slightly convex, with anterior margin below level of margin of mesoventrite, short longitudinal striae between mesocoxae and oblique mesal striae, shallowly impressed posterior centre; apical stripe somewhat convex, not impressed; metacoxal process inflexed, with margin sinuate, notched near coxae. Submesocoxal lines margined by fairly fine punctures and elongate striae. Metanepisterna about 0.03- 0.05 mm wide. Metanepisternal suture impunctate, straight, curved along margin of metepimeron. Ventrite Iwithout basomedian hump, with punctulate microsculpture, distinctly punctate along basal margin. Following ventrites with well visible punctulate microsculpture. Protarsomeres lacking prominent ventral lobe.

♂: Protarsomeres Ito III slightly widened, protarsomere Iabout as wide as half of protibial apex, following two tarsomeres hardly narrower. Protarsomere Iabout as long as following three tarsomeres combined. Apicoventral pair of long setae of protarsomere III not flattened apically. Aedeagus as Figs 46 -48, 0.93 mm long.

♀: Gonocoxite as Fig. 48 , without gonostyle.

Distribution. Indonesia: Papua .

Etymology. The species epithet is a Latin adjective meaning striate.

Comments. This species may be distinguished from its Papuan congeners by the striae margining submesocoxal lines. Its aedeagal characters are similar to those of B. riedeli and B. rufulum , the middle section of the parameres is significantly narrower than that of these two species, and the internal sac has a single, narrow semi­circular sclerite.

Figures

Figs 39-49. 39–41, Bironium riedeli sp. nov.: 39 – Paramere, ventral view, scale = 0.1 mm; 40 – Internal sac, scale = 0.1 mm; 41 – Gonocoxite, scale = 0.05 mm. 42–45, Bironium rufulum sp. nov.: 42, 43 – Aedeagus in dorsal and lateral views, scale = 0.2 mm; 44 – Paramere in ventral view, scale = 0.1 mm; 45 – Gonocoxite, scale = 0.05 mm. 46–49, Bironium striatum sp. nov.: 46, 47 – Aedeagus in dorsal and lateral views, scale = 0.2 mm; 48 – Paramere in ventral view, scale = 0.1 mm; 49 – Gonocoxite, scale = 0.05 mm.