Baeocera chamba, Löbl, 2023

Löbl, Ivan, 2023, Baeocera chamba sp. nov., an unusual new Scaphisomatini (Coleoptera: Staphylinidae: Scaphidiinae) from North India, Acta Musei Moraviae, Scientiae biologicae 108 (1 - 2), pp. 35-38 : 36-37

Baeocera chamba sp. nov.

Figs 1 4

Type material. Holotype, male, N. INDIA, Uttaranchal state, 30 km N of Rishikesh , NW of CHAMBA , Arakot vill. env. 1500 m, 29 31.vii.2003 Z. Kejval & M. Trýzna lgt. ( MHNG).

Description. Length 1.98 mm, width 1.42 mm. Head with frons and vertex very finely punctate, with shortest intervals between eyes 0.22 mm, nearly a half of maximum head width with eyes in dorsal view. Head, body rufous, femora and tibiae uniformly rufous, tarsi yellowish, antennomeres I and II light rufous, antennomeres II to VI yellowish, the following antennomeres light brown. Length/width ratios of antennomeres III 38/8: IV 39/8: V 45/10: VI 43/9: VII 45/10: VIII 40/10: IX 42/15: X 42/15: XI: 51/15. Lateral margins of pronotum and elytra separately arcuate. Pronotum with lateral margins evenly rounded; lateral margin carinae hardly visible in dorsal view; lateral margin striae impunctate; discal punctation very fine, shallow and poorly delimited, hardly visible at magnification 50 times, Exposed part of scutellum rounded at tip. Elytron weakly narrowed apicad, with lateral margin rounded, lateral margin carinae visible anterior of mid­length in dorsal view, lateral margin stria punctate, apical crenulation distinct near inner angles, sutural stria parallel to suture up to apical third, converging in apical third, curved at base and forming deep basal stria gradually narrowing to basal margin and joined with lateral stria; adsutural area flat, with row of very fine punctures; discal punctation fine, much coarser than pronotal punctation, punctures rather poorly delimited, puncture intervals mostly about two to three times as large as puncture diameters. Hind wings fully developed. Hypomeron smooth. Mesoventer distinctly punctate. Mesepimeron four times as long as wide and slightly more than twice as long as shortest interval to mesocoxa. Mesanepisternum with few extremely fine and scattered punctures. Metaventrite in median part flattened, with rather coarse punctures at each side and posterior smooth mesal stripe; lateral parts of metaventrite with scattered, extremely fine punctures; submesocoxale areas about 0.02 mm long, as long as tenth of shortest interval to metacoxae; submesocoxal lines parallel, coarsely punctate, with punctures not elongate and not extending lateral mesocoxae. Metanepisternum flat, smooth, 0.12 mm wide, with straight, deep, impunctate suture. Ventrite I with basal puncture row interrupted between metacoxae, consisting of coarse punctures separated by slightly elongate wrinkles; punctation extremely fine, similar to that on metaventral sides; macrosetae absent. Ventrites II to IV with pair of admesal macrosetae. Ventrite VI with six macrosetae.

Male. Protarsomeres I to III strongly widened, I somewhat narrower than apex of protibial. Aedeagus ( Figs 1 4 ) 0.70 mm long.

Etymology. The species epithet is the name of the North Indian district in which the species was found.

Differential diagnosis. To date, 14 species of Baeocera are known to occur in the north Indian state of Uttarakhand, formerly Uttaranchal Pradesh ( LÖBL, 2018). The new species may be distinguished from them, as from all other Old World congeners, by the combination of the following characters: Body about 2 mm long, uniformly light rufous; antennomeres VII and VIII similar, much narrower than antennomere IX; elytron with basal stria deep, gradually approaching basal margin and joining lateral stria; hypomeron smooth, lateral parts of metaventrite extremely finely punctate; metanepisternum broad, with deep, impunctate suture; punctures margining submesocoxal and submetacoxal lines not elongate; abdomen extremely finely punctate; aedeagus symmetrical, weakly sclerotized; median lobe with unsplit dorsal valve overlapping ostium; internal sac bulbous with basal plates and membranous ejaculatory duct free, lacking supporting sclerites. This new species would fall in the key to the Himalayan species of Baeocera ( Löbl, 1992) under the couplet 5, to B. callida Löbl, 1986 and B. hamifer Löbl, 1977 , both very distinct externally and by their genital characters. Baeocera chamba cannot be placed in any of the recognized species­groups and its relationships to them are unknown.

Figures

Figs 1-4. Baeocera chamba sp. nov., genital characters: 1, 2 – Aedeagus in dorsal and lateral views; 3 – Paramere in ventral view; 4 – Internal sac. Scales = 0.1 mm.