Bironium taurus, 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 : 245-247

Bironium taurus sp. nov.

( Figs 50 -53)

Type material. Holotype ♂, IRIAN JAYA Jayawijaya Prov., Borme . 1000- 1300 m, 13- 18.VIII.92, leg. A. Riedel ( MHNG).

Description. Length 2.45 mm, width 1.48 mm. Head and thorax blackish, elytra, abdomen and appendages brown or reddish­brown. Pronotal punctation extremely fine and scattered, hardly visible at 100 times magnification. Scutellum triangulate. Elytra lacking humeral humps; adsutural areas distinctly raised; sutural and lateral striae sparsely punctate; basal striae entire, joined to lateral striae; prevailing discal punctation similar to pronotal punctation, several larger punctures scattered on disc. Mesoventrite convex, impunctate, lacking microsculpture, with well delimited mesal ridge extended from paxillum nearly to apical margin and becoming lower and broader apically, and with striae on mesocoxal process. Metaventrite not microsculptured, entirely very finely punctate. Median part of metaventrite impressed, with anterior margin below level of margin of mesoventrite, longitudinally striate between mesocoxae, deeply impressed at centre of anterior margin; with two coarse admesal punctures; apical stripe somewhat flattened, not impressed; metacoxal process inflexed, with slightly concave margin. Submesocoxal lines margined by coarse punctures. Metanepisterna about 0.05 mm wide. Metanepisternal suture impunctate, straight, ending comparatively far from margin of metepimeron. Ventrite Iwithout basomedian hump, with punctulate microsculpture evanescent on lateral areas, impunctate along basal margin. Following ventrites with well visible punctulate microsculpture. Protarsomeres lacking prominent ventral lobe.

♂: Protarsomeres Ito III widened, protarsomere Iabout as wide two thirds of protibial apex, following two tarsomeres narrower. Protarsomere Iabout as long as following two tarsomeres combined. Apicoventral pair of long setae of protarsomere III not flattened apically. Aedeagus as Figs 50 -53, 1.20 mm long.

Distribution. Indonesia: Papua .

Etymology. The species epithet is a Latin noun meaning bull. It refers to the two prominent processes of the median lobe of the aedeagus.

Comments. This species is unique in having robust processes on the ventral side of the aedeagus, near bases of the parameres. It may be also distinguished from most congeners by the conspicuously elongate widened part of the parameres. In external characters it is similar to B. albertisi from which it may be readily distinguished by the impressed median part of the metaventrite and the impunctate basal margin of ventrite I.

Figures

Figs 50-53. Bironium taurus sp. nov.: 50, 51 – Aedeagus in dorsal and lateral views, scale = 0.2 mm; 52 – Paramere and apical half of median lobe, in ventral view, scale = 0.2 mm; 53 – Apical part on median lobe, in lateral view, scale = 0.1 mm.