Scopaeus posoanus Frisch, spec. nov.

(Figs 9, 34, 71 –73, 126, 127, 155, 156)

Type specimens: Indonesia, Sulawesi Tengah: Holotype ♂, Poso: Tentena – Taipa (Lake Poso), (01°47’58’’S, 120°31’48’’E), 530 m, 11.5.2017, leg. Frisch (MZB) . Paratypes (14 specimens): 9 ♂, 4 ♀, same data as holotype (MFNB, MZB); 1♀, Poso: Tentena – Peura (Lake Poso), (01°47’59’’S, 120°38’08’’E), 550 m, 9.5.2017, leg. Frisch (MFNB) .

Description: Habitus and coloring as in Fig. 9. Head subquadrate. Antennae with penultimate segment somewhat elongate. Mesotibia slender. Forebody surface with fine, setose punctation, shiny; abdomen matter than forebody. Pubescence of body surface short, decumbent, without conspicuous macrosetae. Body black-brown except for yellow-brown posterior fourth of elytra, light brown tip of abdomen, medium brown maxillary palps with darker penultimate segment, and yellow-brown legs with darker brown femora gradually lighter towards distal ends; antennae with scapus medium brown, from blackish pedicellus gradually lighter towards segment 6, segments 7 – 11 yellow-brown. Total body length 3.4 – 3.7 mm; forebody length 2.0 – 2.1 mm.

Male: Abdominal sternite VII with emargination in median third of posterior twelfth with wide, triangularly concave median lobe, appearing like three small, close, triangular incisions (Fig. 126). Emargination in posterior fifth of abdominal sternite VIII wide, triangular, somewhat convex in middle; disc of sternite VIII in posterior two-thirds with wide, light, shallow, spaciously setose depression divided in two lateral portions by darker, somewhat raised, longitudinal midline (Fig. 127). Aedeagus (Figs 34, 71 – 73) about 0.9 mm long with asymmetrical distal lobes; apical lobes, in lateral view, broad with triangular, dorsad curved ends (Figs 34, 71), in ventral view rhomboid in distal portion with small, ventroproximad pointing ends and gradually widened ventrolaterad in proximal portion (Figs 72, 73); ventral margin of dextral apical lobe with proximad pointing tooth with lobate apex (Fig. 71: arrow IV); dorsal lobe weakly sclerotized, triangular distally (Figs 72, 73: arrows V, VI); flagellum long, notably projecting from apical lobes dorsally in basal portion, then semicircularly curved ventroproximad (Figs 34, 71) and continued in dextrodistad curved apical portion (Fig. 72); ventral lobe strongly projecting, subrectangularly widened ventrally, with acute, ventroproximal end (Fig. 71); setose lateral lobes absent; median foramen wide, elongate, limited by triangularly distad bent, transverse ridge (Fig. 72).

Female: Bursal duct about three times as long as sperm pump, membranous in proximal half; bursa membranous (Fig. 155, 156).

Phylogeny: Scopaeus posoanus is to be classified in the S. gracilis species group (Frisch et al. 2002: 39).

Distribution: Scopaeus posoanus is known only from the vicinity of Lake Poso, Sulawesi Tengah.

Etymology: The epithet posoanus (adjective, Latin, derived from the noun Poso, with suffix – anus, which indicates the geographical affiliation) refers to the type localities of the new species at Lake Poso, Sulawesi.