Scaphobaeocera plana, 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 : 115

Scaphobaeocera plana sp. nov.

Figs 24-27

Material examined: Holotype; MHNG; male; MALUK: Kai Besar , G. Tukrau nr Bombay , 4.IX.81, D. Agosti F911035 .

Paratype; MHNG; male; with the same data as the holotype but 5.IX. and F911046 .

Etymology: The species epithet is a Latin adjective meaning flat.

Diagnosis: Body-length 0.90 mm long, body light brown, not microsculptured and not iridescent; antennomere VIII exceeding half-length of antennomere VII, antennomere XI slightly longer than antennomere X and nearly 3 times as long as wide; elytra lacking parasutural stria; hypomeron lacking longitudinal striae; aedeagus as Figs 24-27 , with broad basal bulb, short, strongly sclerotized and bent apical process and short, bilobed apicodorsal plate, parameres expanded, notched mesally, internal sac with short, robust, incurved sclerite.

Description: Length 0.90 mm, width 0.52 mm, dorsoventral diameter 0.47 mm. Head, body, femora and tibiae nearly uniformly light brown, elytra somewhat lighter near apices, tarsi and antennae lighter than tibiae. Length/width ratios of antennomeres as: III 10/5: IV 13/5: V 14/5: VI 12/5: VII 23/10: VIII 13/8: IX 24/10: X 27/11: XI 33/12. Pronotum finely punctate, not microsculptured. Scutellum concealed. Elytra not iridescent, not microsculptured, lacking parasutural striae, sutural striae deep, curved near base, discal punctation coarser than pronotal punctation. Hypomera not microsculptured, smooth, lacking longitudinal stria. Mesoventrite with low mesal ridge. Metaventrite weakly convex between mesocoxae, lacking median stria; entire median area rather coarsely and densely punctate, with some punctures about as large as puncture intervals, pubescence short. Lateral parts of metaventrite very finely punctate, not microsculptured. Submesocoxal areas about 0.03 mm, as half of shortest interval to metacoxae, submesocoxal lines appearing impunctate. Metanepisterna about 0.05 mm wide, flat, not narrowed anteriad, impunctate, with straight suture reaching metepimera. Tibiae straight. Abdomen not microsculptured, very finely punctate, coarse basal punctures of ventrite I excepted.

Male characters: Protarsomeres I to III strongly widened, about as wide as apices of protibiae. Aedeagus as in Figs 24-27 , 0.36-0.38 mm long. Apical process of median lobe short, curved and strongly inflexed, in apical section nearly perpendicular to basal bulb. Articular process not prominent. Dorsal side of basal bulb produced to form bilobed, strongly sclerotized plate. Internal sac with strongly sclerotized, proximally hook-like piece.

Habitat: Secondary forests on limestone, 200-400 m, dead log and leaf litter infested by fungi.

Distribution: Indonesia: Moluccas, Kai Besar Island.

Remarks: The species differs from most congeners by its body comparatively weakly convex, lacking microsculpture, and the elytra lacking parasutural striae, in combination. The aedeagal characters of S. plana are unique. The presence of a narrow apicodorsal process of the median lobe, the shape of the parameres and that of the sclerite of the internal sac lacking a flagellum are diagnostic. The generic assigned is therefore tentative. Several character states used to define the Scaphisomatini genera (see Leschen & Löbl, 2005) have not been verified as they may be seen only on slides of the head and thorax, requiring more available specimens.

Figures

Figs 23-29. Scaphisoma donati sp. nov. (23) Parameres in ventral view, scale bar = 0.2 mm. Figs 24-27. Scaphobaeocera plana sp. nov. (24, 25) Aedeagus in dorsal and lateral views, scale = 0.1 mm. (26) Paramere in ventral view, scale = 0.05 mm. (27) Apical part of median lobe, in lateral view, scale = 0.05 mm. Figs 28, 29. Scaphoxium lobatum sp. nov. (28) Aedeagus in ventral view, scale = 0.1 mm. (29) Apex of median lobe with extruded internal sac and right paramere, in dorsal view, scale = 0.05 mm.