Bironium punctatum, 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 : 239-243

Bironium punctatum sp. nov.

( Figs 31 -36)

Type material. Holotype ♂: IRIAN JAYA Prov. Jayawijaya, Samboka Upper Kollf River , ca 200 m, 10- 14.X.96, Riedel ( MHNG) . Paratypes 2 ♂, 2 ♀, with the same data as the holotype ; 1 ♀, Papua , Jayawijaya Prov., Lereh , 300- 550 m, 25.I.1996, A. Riedel ( MHNG) ; 1 ♀, Papua , Jayawijaya Prov., Sumo - Uarn , 100- 1000 m, 26- 27.VI.1994, A. Riedel ( MHNG).

Description. Length 1.95- 2.15 mm, width 1.20- 1.34 mm. Head, thorax and elytra black or blackish­brown, abdomen very dark brown, light brown to yellowish apical segments excepted. Legs reddish­brown, with tarsi lighter than tibiae, antennae light brown. Pronotum very finely punctate. Scutellum rounded. Elytra lacking humeral humps; adsutural areas hardly raised; sutural and lateral striae punctate; basal striae entire, very shallow and hardly visible at humeral areas. Elytral disc impunctate along base and lateral striae, with very fine, hardly visible punctation on apical third; prevailing discal surface coarsely punctate. Coarse punctures forming two longitudinal rows, outer row impressed, interval between rows somewhat raised. Mesoventrite weakly convex, with well delimited mesal ridge extended from paxillum nearly to apical margin and with longitudinal striae evanescent anteriorly; area near lateral margins of mesocoxal process densely punctate and uneven. Metaventrite not microsculptured. Median part of metaventrite with minute hump between mesocoxae, flat anterior of hump, impressed posterior of hump, with anterior margin below margin of mesoventrite, bearing few longitudinal striae at each side of mesocoxal process; hump and area posterior of hump irregularly punctate; apical stripe flat, not impressed; metacoxal process horizontal, with rounded margin. Lateral parts of metaventrite coarsely punctate, except near apical margin. Submesocoxal lines coarsely punctate. Metanepisterna narrow, about 0.03 mm wide. Metanepisternal suture impunctate, straight, not curved along metepimeron, reaching or nearly reaching margin of metepimeron. Ventrite Iwithout basomedian hump, with punctulate microsculpture, distinctly punctate along basal margin. Following ventrites with punctulate microsculpture. Protarsomeres lacking prominent ventral lobe.

♂: Protarsomeres Ito III distinctly widened, protarsomere Iabout as wide as two thirds of protibial apex, somewhat shorter than following two tarsomeres combined; protarsomeres II and III slightly narrower that protarsomere I. Apicoventral pair of long setae of protarsomere III not flattened apically. Aedeagus as Figs 31 -35, 0.86 mm long.

♀: Gonocoxite as Fig. 36 , without gonostyle.

Distribution. Indonesia: Papua .

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

Comments. This species may be readily distinguished from its congeners having similar body­colour by the pattern of the elytral punctation combined with the coarsely punctate lateral parts of the metaventrite, and the presence of a hump situated between mesocoxae. The comparatively narrow parameres lacking lobes are similar to those in B. flavapex while the hook­like shape of the apex of the median lobe is unique.

Figures

Figs 30-38. 30 – Bironium ornatum sp. nov.: gonocoxite, scale = 0.05 mm. 31–36, Bironium punctatum sp. nov.: 31, 32 – Aedeagus in dorsal and lateral views, scale = 0.2 mm; 33 – Tip of median lobe, scale = 0.05 mm; 34 – Internal sac, scale = 0.05 mm; 35 – Paramere in ventral view, scale = 0.1 mm; 36 – Gonocoxite, scale = 0.05 mm. 37–38, Bironium riedeli sp. nov.: Aedeagus in dorsal and lateral views, scale = 0.1 mm.