Baeocera humicola, Löbl, 2022

Löbl, Ivan, 2022, Supplement to the knowledge of the Scaphidiinae (Coleoptera: Staphylinidae) of the Moluccas, Revue suisse de Zoologie 129 (1), pp. 103-118 : 104

Baeocera humicola sp. nov.

Figs 1-3

Materiel examined: Holotype; MHNG; male; MALUK: Kai Besar , Bombay, G. Dab , 3.IX.81, D. Agosti F911019 .

Paratypes; MHNG; 3 females, with the same data as the holotype ; – MHNG; 1 male; MALUK: Kai Besar , G. Tukrau nr Bombay , 4.IX.81, D. Agosti F91035 .

Etymology: The species epithet is a noun meaning living in humus.

Diagnosis: The species is defined by the following characters in combination: Body-length about 1.20 mm, body blackish-brown; pronotum and elytra not microsculptured; lateral margins of pronotum and elytra separately arcuate, pronotum finely punctate; elytron entirely coarsely punctate, with basal stria extended to basal mid-width, sutural stria entire; hypomeron, mesanepisternum and mesepimeron impunctate; metaventrite and ventrite I coarsely punctate; ventrite I without basal wrinkles or striae; aedeagus symmetrical, with apical process abruptly narrowed near apex (lateral view), parameres hardly bent, nearly evenly broad, internal sac with complex sclerites, as in Fig. 3 , lacking membranous scale or denticle-like structures.

Description: Length 1.18-1.20 mm, width 0.86- 0.88 mm. Head and most of body blackish-brown, femora and tibiae lighter, reddish-brown, tarsi and antennae yellowish. Head with interocular distance about as dorsoventral eye diameter. Antennomere II about as long antennomere III. Length/width ratios of antennomeres as: III 23/5: IV 23/5: V 31/6: VI 29/6: VII 34/9: VIII 30/7: IX 37/11: X 37/13: XI 40/15. Pronotum and elytra separately arcuate. Pronotum not microsculptured, pronotal punctation hardly visible at 50 times magnification; lateral carinae of pronotum to part exposed in dorsal view. Point of scutellum exposed. Elytra nearly completely covering abdomen. Elytron weakly narrowed apically, with lateral margin rounded near base and apex, oblique in middle; lateral margin carinae concealed in dorsal view, adsutural area flat and narrow; sutural stria punctate, extended along base to form basal stria reaching basal mid-width; lateral stria punctate. Elytral disc not microsculptured, with punctation well delimited, much coarser than on pronotum, nearly regular, puncture intervals mostly two to three times puncture diameters. Hind wings fully developed. Hypomeron, mesanepisternum and mesepimeron impunctate. Mesoventrite punctate, without median ridge, fused with metaventral process. Mesepimeron about four times as long as wide and about three times as long as distance to coxa. Median part of metaventrite flattened, coarsely and densely punctate around smooth centre. Lateral area of metaventrite with punctation coarse and dense, denser than that on elytron; punctures well delimited, to part as large as puncture intervals, largest near anterior margin, evanescent near metacoxa. Submesocoxal lines parallel, with marginal punctures smaller than punctures on lateral area of metaventrite and not extended laterally along margin of metaventrite. Submesocoxal areas about 0.02 mm long, about as fourth of shortest interval to metacoxae. Metanepisternum flat, fused with metaventrite, its margin indicated by outer puncture row of metaventrite. Tibiae straight. Abdomen not microsculptured. Ventrite I about as coarsely and densely punctate as lateral area of metaventrite, basal punctures not enlarged and not elongate, not interrupted in middle, basal striae absent. Following ventrites finely punctate.

Male characters: Protarsomeres I to III hardly widened. Aedeagus ( Figs 1-3 ) 0.32 mm long, weakly sclerotized, symmetrical. Apical process of median lobe gradually narrowed, with tip bent and acute in lateral view. Parameres hardly bent in both, dorsal and lateral, views and throughout nearly evenly wide. Internal sac with sclerotized complex as in Fig. 3 , with long, apically widened flagellar guide-sclerite, lacking membranous scale- or denticle-like structures.

Habitat: Secondary forests on limestone, 200-400 m, litter from dead log and rotting leaves.

Distribution: Indonesia: Moluccas, Kai Besar Island.

Remarks: The species is a member of the B. lenta group. It falls in the key to the Moluccan species ( Löbl, 2015a) to B. vafra Löbl, 2015 . It may be distinguished by the parameres which are not widened and not bent apically, and by the bent tip of the apical process of the median lobe. In addition, the membranes of the internal sac of B. vafra bear denticle-like structures absent from B. humicola . The aedeagal characters of this new species suggest relationships with the New Guinean B. papua ( Löbl, 1975) which may be readily distinguished by the ventrite I bearing basal wrinkles.

Figures

Figs 1-9. Baeocera humicola sp. nov. (1, 2) Aedeagus in dorsal and lateral views, scale bar = 0.1 mm. (3) Internal sac, scale bar = 0.05 mm. Figs 4-6. Baeocera incurva sp. nov. (4, 5) Aedeagus in dorsal and lateral views, scale bar = 0.1 mm. (6) Internal sac, scale bar = 0.05 mm. Figs 7-9. Baeocera notata sp. nov. (7) Aedeagus in dorsal view, scale bar = 0.1 mm. (8) Paramere in ventral view, scale = 0.05 mm. (9) Internal sac, scale = 0.05 mm.