Bironium rufulum, 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

Bironium rufulum sp. nov.

( Figs 42 -45)

Type material. Holotype ♂, INDO: West Papua Manokwari Prov. Testega , 1200 m 13.IV.93, A. Riedel ( MHNG) . Paratypes 5 ♀, with the same data as the holotype ( MHNG).

Description. Length 1.80-2.0 mm, width 1.02- 1.80 mm. Head, thorax, elytra and legs uniformly rufous, abdomen lighter, with apical segments yellowish, antennae yellowish. Pronotum very finely punctate. Scutellum triangulate. Elytra lacking humeral humps; adsutural areas hardly raised; sutural and lateral striae impunctate; basal striae interrupted at level of humeral areas; discal punctation as fine as pronotal punctation. Mesoventrite convex, lacking mesal ridge, impunctate, not microsculptured and not striate. Metaventrite not microsculptured, impunctate. Median part of metaventrite flattened between mesocoxae, with anterior margin below level of margin of mesoventrite, distinct longitudinal striae extended to mid­length; centre with large, shallow impression situated posterior of mid­length; apical stripe flat, not impressed; metacoxal process horizontal, margin notched in middle and near coxae. Submesocoxal lines with few coarse punctures. Metanepisterna to large part concealed, exposed posterior section about 0.01- 0.02 mm wide. Metanepisternal suture impunctate, curved apically, ending well anterior margin of metepimeron. Ventrite Iwithout basomedian hump, not microsculptured, lacking puncture row along basal margin. Following ventrites with punctulate microsculpture. Protarsomeres lacking prominent ventral lobe.

♂: Protarsomeres Ito III hardly widened, protarsomere Iabout as wide as half of protibial apex, following two tarsomeres hardly narrower. Protarsomere Inearly as long as following two tarsomeres combined. Apicoventral pair of long setae of protarsomere III not flattened apically. Aedeagus as Figs 42 -44, 0.70 mm long.

♀: Gonocoxite as Fig. 45 , without gonostyle.

Distribution. Indonesia: West Papua .

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

Comments. The species may be distinguished from most Papuan congener by the mesoventrite lacking, or having a reduced mesal ridge, as it is in B. basicolle , B. bicolor , B. flavapex , and B. maindai . These four species have elytra with entire basal striae and wider exposed parts of the metanepisterna, and two of them, B. maindai and B. bicolor , differ drastically by their body size and colour pattern, respectively. The habitus and the aedegus of B. rufulum are similar to those of B. riedeli , suggesting relationships. However, the mesoventrite with a robust mesal ridge, and the subquadrate lobes and the broad apical section of the parameres of the latter species are diagnostic.

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.