Bironium amicale, Löbl, 2012

Löbl, Ivan, 2012, On a collection of Scaphisomatini (Coleoptera: Staphylinidae: Scaphidiinae) from West Malaysia, Acta Entomologica Musei Nationalis Pragae 52 (1), pp. 173-184 : 174-176

Bironium amicale sp. nov.

( Figs. 1–4 )

Type material. HOLOTYPE: ♂, ‘ MALAYSIA, Pahang Cameron Highlands Tanah Rata vill. env. Gunung Jasat [Mt.]; 1470–1705 m 04°28.4–7’ N, 101°21.6–22.1’ E Jiří Hájek leg. 18.iv.–10.v.2009 ’ ( NMPC). PARATYPES: 2 ♂♂ 6 ♀♀, ‘ MALAYSIA, Pahang Cameron Highlands Tanah Rata vill. env. Gunung Jasat [Mt.] ; 1470–1705 m 04°28.4–7’N, 101°21.6–22.1’ E Jiří Hájek leg. 18.iv.–10.v.2009 ’ ( NMPC, MHNG); 3 ♂♂ 1 ♀, ‘W. Malaysia Pahang Fraser’s Hill 23.– 24.6.1995 110 km N of K. Lumpur lgt. S. & E. Becvar’ ( MHNG).

Description. Length 2.20–2.70 mm, width 1.30– 1.68 mm. Body brown to dark reddish-brown, elytra reddish or ochraceous, each with two dark, irregular, transversal fasciae ( Fig. 1 ). Anterior fascia extended apically in middle and along sutural striae. Margins of posterior fascia irregular and not well delimited, narrowed mesally, sometimes reaching apical elytral margin. Apical abdominal segments and femora reddish, tibiae about as light parts of elytra, tarsi, antennae and mouth-parts lighter. Length ratio of antennomeres as: II 16: III 22: IV 35: V 30: VI 45: VII 61: VIII 53: IX 45: X 37: XI 36 (holotype). Pronotum very finely punctate, not microsculptured. Exposed tip of scutellum small. Elytra with deep, finely punctate sutural striae. Adsutural areas raised. Humeral protuberance low, impunctate. Discal punctation of elytra consisting of large, coarse punctures forming oblique, more or less regular rows. Coarse punctures usually smaller or about as large as puncture intervals, becoming irregular near elytral apices. Two punctures rows impressed apically, area along outer impressed row swollen. Punctation on hypomera and mesepisterna hardly visible and very sparse. Mesoventrite convex, lacking ridge and not striate. Middle of metaventrite convex, transversally impressed along metacoxale process, impunctate except for few large punctures situated between mesocoxa, coarse submesocoxale puncture rows and fairly distinct punctures in transverse impression. Lateral parts of metaventrite with few large, coarse punctures. Exposed abdominal tergites and ventrites with punctulate microsculpture. First sternite with distinct median protuberance, impunctate except for submetacoxal rows of coarse punctures. Pro- and mesotibiae slightly curved, longitudinally striate. Protibiae distinctly thickened apically. Metatibiae straight.

Male. Protarsi without lobed segments, segments 1 to 3 strongly widened, segment 1 about as wide as apex of protibia, following segments slightly narrower. Aedeagus ( Figs. 2–4 ) 0.65–0.70 mm long. Median lobe weakly sclerotized, with apical process in same plan as basal bulb and not inflexed, apically moderately narrowed, with obtuse tip. Parameres arcuate in dorsal view, almost straight in lateral view, explanate apically. Internal sac with central sclerotized plate extended proximally by two processes, semicircular basal margin and membranes consisting of finely striate structures.

Differential diagnosis. The aedeagal characters of this species are similar to those of the Philippine B. trisulcatum (Heller, 1917) . These two species share the shape of the median lobe of the aedeagus and also possess similar parameres. However, B. trisulcatum has the apical process of the median lobe weakly inclined and the parameres narrower, in dorsal view being almost straight, not widened at the apex. Bironium amicale sp. nov. may readily be distinguished from B. trisulcatum by its colour pattern that is similar to that of B. nepalense Löbl, 1992 , although the shape of the anterior elytral fasciae is distinctive.

Etymology. The name is a Latin adjective, referring to the friendly attitudes of the collectors of the species.

Figures

Fig. 1. Bironium amicale sp. nov., paratype.

Figs. 2–4. Bironium amicale sp. nov. 2 – aedeagus in dorsal view; 3 – detail of internal sac; 4 – aedeagus in lateral view. Scale bars: 0.1 mm (Figs. 2, 4); 0.2 mm (Fig. 3);