Bironium bicolor, 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 : 231

Bironium bicolor sp. nov.

( Figs 7 10)

Type material. Holotype ♂, NEW GUINEA centr. BALIEM TAL­ 1700m MARCH 1992 leg. Jiłí KOLIB` ¨ ( NHMB). Paratypes 2 ♂, INDONESIA, Papua , Jayawijaya Prov., Nalca , 1900- 2100 m, 8.IX.1992, A. Riedel ( MHNG).

Description. Length 2.23 2.40 mm, width 1.34- 1.47 mm. Head, pronotum and legs ochraceous, elytra black, hypomera and venter of thorax reddish­brown, abdomen yellowish, legs and antennae about as light as pronotum. Pronotum very finely punctate. Scutellum triangulate. Elytra lacking humeral humps, sulci and impressions; adsutural areas slightly raised; sutural and lateral striae impunctate; basal striae shortened, broadly interrupted laterally of elytral mid­width. Elytral punctation very sparse and very fine, similar to pronotal punctation. Mesoventrite convex, smooth, appearing impunctate, with short and inconspicuous mesal ridge posterior of paxillum, without impressions. Metaventrite impressed in middle, with several hardly visible oblique striae converging toward mesal impression, not microsculptured and entirely impunctate, punctures absent from submesocoxal lines; anterior margin of mesocoxal process nearly in level with margin of mesoventrite. Metacoxal process horizontal, slightly impressed, margin weakly rounded. Metanepisterna narrow, in anterior halves about 0.02- 0.03 mm wide. Metanepisternal suture impunctate, curved along metepimeron and nearly reaching margin of metepimeron. Ventrites with punctulate microsculpture, appearing impunctate, few distinct punctures along basal margin excepted. Ventrite Iwithout distinct basal hump. Protarsomeres III lacking prominent ventral lobe.

♂: Protarsomeres Ito III slightly widened, similar in width, each about as wide as half of protibial apex. Protarsomere Islightly shorter than protarsomeres II and III combined. Protarsomere III with apicoventral pair of long setae gradually widened, reaching about level of mid­length of protarsomere V. Aedeagus as Figs 7 -10, 0.98- 1.10 mm long.

Distribution. Indonesia: Papua .

Etymology. The species epithet is a Latin adjective referring to bicolorous pattern of the elytra and pronotum.

Comments. This species may be easily distinguished from its congeners by the colour pattern, teneral specimens, as the two paratypes, excepted. The species is characterized by the aedeagal characters, and in external characters by the mesally impressed metaventrite in combination with the impunctate submesocoxal lines and the smooth mesoventrite bearing a very short mesal ridge. The parameres are similar to those of B. borneense Löbl. The latter species differs conspicuously by the coarse elytral punctures forming elongate rows. The "Tal" on the label of the holotype means valley in German.

Figures

Figs 1-10. 1–6, Bironium albertisi sp. nov.: 1, 2 – Aedeagus in dorsal and lateral views, scale = 0.2 mm; 3 – Tip of median lobe in lateral view, scale = 0.1 mm; 4 – Internal sac, scale = 0.1 mm; 5 – Paramere in ventral view, scale 0.1 mm; 6 – Gonocoxite, scale = 0.05 mm. 7–10, Bironium bicolor sp. nov.: 7, 8 – Aedeagus in dorsal and lateral views, scale = 0.2 mm; 9 – Internal sac, scale = 0.1 mm; 10 – Paramere in ventral view, scale = 0.1 mm.