Baeocera stewarti, Löbl, 2018

Löbl, Ivan, 2018, Review of the genus Baeocera of Chile (Coleoptera: Staphylinidae: Scaphidiinae), Linzer biologische Beiträge 50 (2), pp. 1305-1317 : 1310

3.9 Baeocera stewarti nov.sp. ( Figs 10-12 )

T y p e m a t e r i a l: Holotype ♂, CHILE: Llanquihue , Frutillar Bajo , Univ. Chile Forest. Res. 22.CII.[sic, XII] 84-2.II.85 S&JPeck, 100 m, FIT, ravine mixed forest ( MHNG) . Paratypes: 1♂, CHILE: Llanquihue ; Salto Petrohue , V. Perez N.P. 23.XII.84-4.II.85 S&JPeck, 150m, FIT, mixed moist forest ; 1 specimen, CHILE: X Reg. Prov. Chiloé Cucao, 30 km SW Castro, NP Chiloé , 30 m, temp. rain forest, 4-6.I.1991 Agosti & Burckhardt nr 29a ; 1♀, CHILE: Palena Prov. 37 km SE Chaiten 28.XII.84 - 30.I.85 S&JPeck, FIT, 60 m riverside 2nd forest (all MHNG) .

D e s c r i p t i o n: Length 1.40-1.50 mm, width 0.84-0.88 mm. Frons brown posterior level of eyes, becoming gradually lighter anteriad. Pronotum ochraceous along base and anterior margin, with brown V-shaped transverse band. Elytron with basal sixth to fifth and apical third ochraceous, brown to blackish on prevailing surface. Ventral side of thorax and most of abdomen brown to blackish. Apical abdominal segments ochraceous to yellowish. Antennae light brown, with yellowish antennomeres I and II. Legs brown, femora about brown, tibiae and tarsi lighter. Eye width as half of shortest interval between eyes. Length/width ratios of antennomeres as: III 15/6: IV 20/7: V 24/8: VI 21/8: VII 25/10: VIII 24/10: IX 28/14: X 28/15: XI 45/15. Dorsal and ventral sides of body not microsculptured, punctation very fine, hardly visible at 60 times magnification, fine punctures bordering submesocoxal lines and base of ventrite 1 excepted. Tip of scutellum exposed. Elytra widest posterior basal sixth, distinctly narrowed from widest point toward apices; sutural striae shortened, starting abruptly posterior basal fourth of sutural length, adsutural areas flat. Mesepimera about three times as long as wide and twice as long as intervals to mesocoxae. Mesal part of metaventrite convex, lacking impressions. Submesocoxal areas 0.11 mm long, long as shortest intervals between them and metacoxae; outer margins to part parallel with body-axis, inner margin convex. Metanepisterna flat, about 0.03-0.04 mm wide, parallel-sided, with deep, straight suture. Tibiae straight, thickened apically.

Male characters: Protarsomeres I-III hardly widened. Aedeagus as Figs 10-12 , 0.47- 0.49 mm long.

E t y m o l o g y: The species is named after one of its collectors, Stewart B. Peck (Ottawa), an outstanding taxonomist and a great worker.

C o m m e n t s: The species may be easily distinguished by its colour pattern, notably by the darkened transverse pronotal band, and by the large submesocoxal areas, in combination with the sutural striae of elytra strongly shortened. The aedeagus with wide, obtuse apex of median lobe is unique among the Chilean congeners while the structure of the internal sac suggests relationships to B. chilensis REITTER and B. germaini PIC.

Figures

Figs 8-13: Aedeagi of Baeocera, in dorsal view; (8) B. jarmilae nov.sp., paramere, scale = 0.1 mm; (9) ditto, internal sac, scale = 0.1 mm; (10) B. stewarti nov.sp., scale = 0.1 mm; (11) ditto, parameres, scale = 0.1 mm; (12) ditto, internal sac, scale = 0.05 mm; (13) B. variicolorata nov.sp., scale = 0.1 mm.