(Figs 15 –19)

Type material. Holotype ♂, PAPUA N. G. Morobe Prov. leg. A. Riedel / Aseki, Oiwa, 1600- 1700 m, 11- 12.III.1998 (MHNG). Paratype ♀, Papua New Guinea, Eastern Highlands, Kassem Pass, XI. 1957, J. Sedlacek (MHNG).

Description. Length 3.0- 3.20 mm, width 1.77 - 1.92 mm. Head and body black, with apex of abdomen lighter. Femora and tibiae black, tarsi blackish­brown. Antennae blackish. Pronotum very finely punctate. Scutellum rounded. Elytra with distinct humeral humps; adsutural areas raised; sutural striae with scattered, fine punctures; basal striae shortened, broadly interrupted laterally of elytral mid­width, lateral striae finely punctate in anterior halves. Elytra lacking sulci and impressions, punctation near sutural and lateral striae, and at bases very fine, similar to pronotal punctation, on apical fourth somewhat less fine, on prevailing discal surface rather coarse and irregular. Mesoventrite hardly convex, with robust mesal ridge nearly reaching margin of mesocoxal process, and with oblique striae. Metaventrite impunctate, not microsculptured; impressed mesally; mesocoxal process below level of mesoventrite, longitudinally striate. Metacoxal process slightly oblique, with transverse margin. Metanepisterna narrow, near anterior margins about 0.04 mm wide, weakly widened apically. Metanepisternal suture impunctate, straight and nearly reaching margin of mesepimeron. Abdomen very finely punctate, except for to distinct punctures along basal margin of ventrite I. Mesal area of ventrite I lacking basal bump, with strigulate microsculpture becoming punctulate near apical margin, lateral parts of ventrite Inot microsculptured. Ventrites II to IV and base of ventrite Vwith strigulate microsculpture, prevailing surface of ventrite Vwith punctulate microsculpture. Protarsomeres III lacking prominent ventral lobe.

♂: Protarsomeres Ito III moderately widened, similar in width, each about as wide as two thirds of protibial apex. Protarsomere III longer than following three tarsomeres combined, with apicoventral pair of long setae not widened. Aedeagus as Figs 15 -18, 1.50 mm long.

♀: Gonocoxite with gonostyle, as Fig. 19.

Distribution. Papua New Guinea.

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

Comments. The species may be distinguished from its Papuan congeners by the bodysize. Only four Asian species, B. feai (Achard, 1914), B. grouvellei (Achard, 1920), B. tonkineum (Pic, 1922) and B. yunnanum Löbl, 2020, have the body 3 mm long, or more than 3 mm long, in combination with the entirely black pronotum and elytra. This new species differs also conspicuously from the Papuan congeners by the punctate ventrites and the ventrite Ihaving microsculpture to part consisting of striae. The narrow notch situated posterior of the expanded apical section of the parameres is a unique character, and the gonostyle separates this species from the remaining Papuan Bironium known in females.