Baeocera rudis Löbl, 2021

Löbl, Ivan & Smetana, Aleš, 2021, On the Baeocera Erichson (Coleoptera: Staphylinidae: Scaphidiinae) of Sabah, Malaysia, and a tale on mystified biodiversity, J. Insect Biodiversity 23 (2), pp. 23-42 : 30-31

Baeocera rudis Löbl , sp. nov.

urn:lsid:zoobank.org:act:ECCBFA35-5536-42AD-9D14-B876D86A5638

( Figs 4–7 )

Material examined. Holotype ♂, SABAH: Poring Hot Springs , 500 m 8.V.1987 Burckhardt & Löbl ( MHNG). Paratypes: 4 ♂, Crocker Range, Tenom env., Kalang Waterfall env., 18.VI.98, Kodada & Čiampor ( MHNG) ; 1 ♂, Kibongol village 7 km N Tambunan , 700 m, 20.V.87, Burckhardt & Löbl ( MHNG) ; 1 ♂, Poring Hot Springs, 500 m, 6.V.87, Burckhardt & Löbl ( MHNG) ; 3 ♂, Poring Hot Springs , 550–600 m, 9.V.87, Burckhardt & Löbl ( MHNG) ; 3 ♂, Poring Hot Springs , 500 m, 13.V.87, Burckhardt & Löbl ( MHNG) ; 2 ♂, Poring Hot Springs , 495 m, 21. and 25.VIII.88, Smetana [B135, B148] ( CNC) ; 1 ♂, same data but 510 m, 30.VIII. [B162] ( CNC) ; 9 ♂, Sabalangan River env. 25 km SE Sapulut , 26.06.98, Kodada & Čiampor ( MHNG) .

Description. Length 0.98–1.10 mm, width 0.65–0.70 mm. Body reddish-brown with usually slightly darkened meso- and metaventrite. Apex of abdomen yellowish. Femora and tibiae about as elytra or lighter, tarsi and antennae yellowish. Head with interocular distance about as dorsoventral eye diameter. Lateral contours of pronotum and elytra continuously arcuate. Pronotum not microsculptured, with punctation very fine, hardly visible at 40 times magnification, lateral margin carinae not visible in dorsal view. Scutellum concealed. Elytra not microsculptured, with lateral margins oblique, lateral margin carinae visible in dorsal view only near bases, sutural striae starting near base, parallel, curved along bases to form complete basal striae joined with lateral striae, adsutural areas flat, very finely punctate. Discal punctation fairly coarse and dense on anterior two-thirds of elytron, very fine on apical third, punctures usually smaller than puncture intervals. Hind wings fully developed. Hypomera appearing impunctate. Mesoventrite with short mesal ridge and scattered, coarse punctures. Mesepimera about 2.5 times as long as wide and as intervals to coxae. Entire metaventrite densely and coarsely punctate, punctures round, on lateral areas coarse than on centre, to part larger than puncture intervals; centre flattened. Submesocoxal areas 0.01–0.02 mm long, margined by punctures about as those on lateral areas of metaventrite. Metanepisterna concealed. Tibiae straight. Ventrite I lacking striae, with punctures margining base not or weakly elongate, smaller than those on sides of metaventrite, not interrupted at middle. Remaining abdominal punctation very fine and sparse, hardly visible at 40x magnification.

Male characters. Protarsomeres I to III hardly widened. Aedeagus ( Figs 4–7 ) 0.28–0.34 mm long. Median lobe in dorsal view abruptly narrowed apically, with tip acute and not bent; apical process hardly inflexed, about as long as basal bulb, ventral contour of apical process in lateral view slightly arcuate to oblique. Articular process not prominent. Parameres narrow, not or hardly widened apically, bent in basal halves in dorsal view, slightly sinuate in lateral view. Internal sac with flagellar-guide sclerite gradually narrowed apically, joined basally with flagellum and ring shaped sclerite. Membranes of internal sac lacking denticulate or squamous vesicles, ejaculatory duck not vesicular before entering sclerotized complex.

Differential diagnosis. This species may be distinguished from other members of the Baeocera lenta group having coarse elytral punctures limited onto the anterior two-thirds of the disc, complete basal striae and the ventrite I smooth posterior of basal puncture row, by the metaventrite entirely densely punctate, the concealed scutellum, and the aedeagal characters. The shape of the parameres, the comparatively elongate apical process of the median lobe and the narrow flagellar guide-sclerite are similar to those of B. rufula (Löbl) , and B. secreta and B. semirufa described below. These species share also an internal sac lacking vesicles. Baeocera rudis may be distinguished from them by its parameres narrow and weakly bent near bases, and by the shape of the sclerites of the internal sac.

Distribution. East Malaysia: Sabah.

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

Figures

Figures 1–7. Baeocera spp., aedeagi; (1, 2) B. omnigena sp. nov., in dorsal and lateral views, internal sac extruded, scale = 0.1 mm; (3) ditto, paramere in ventral view, scale = 0.05 mm. (4, 5) B. rudis sp. nov., in dorsal and lateral views, scale = 0.1 mm; (6) ditto, paramere in ventral view, scale = 0.05 mm; (7) ditto, internal sac in dorsal view, scale = 0.05 mm.