Diomus dafushanensis Bi, Peng & Chen, 2023

Diomus dafushanensis Bi, Peng & Chen , sp. nov.

( Fig. 3)

Diagnosis. This species can be distinguished from other Chinese species of Diomus by the unique coloration of pronotum, the abdominal postcoxal lines with short oblique associate lateral lines, ventrite 1 posteriorly medially arcuate and ventrite 2 at middle narrower than both sides.

Description. TL 1.25–1.71 mm, TW 0.88–1.26 mm, TH 0.52–0.75 mm, TL/TW 1.35–1.42, EL/EW 0.97–1.05, PL/PW 0.51–0.52, HW/PW 0.67–0.69, PW/EW 0.71–0.77.

Male. Body moderately ovoid and slightly convex, dorsum with dense and white pubescence ( Figs 3a–f). Head, antennae and mouthparts yellow, tip of mandibles brown ( Fig. 3c). Pronotum black with anterior margin 1/3 and lateral margin yellow, but not reaching posterior margin ( Figs 3a–c). Scutellar shield black. Elytra black with apical half gradually faded from black to dark brown ( Figs 3a–c). Prothoracic hypomeron yellow, prosternum black with sides yellowish brown. Mesoventrite, metaventrite black, and elytral epipleurae dark brown with black margin. Legs yellow to dark brown ( Figs 3b–c).

Eyes densely faceted, small, interocular distance about 0.5 times head width ( Fig. 3c). Antenna shorter than half width of head, composed of 11 antennomeres with antennomeres 7–11 forming a fusiform club. Head and pronotal punctures fine, densely distributed. Surface of elytra with punctures relatively coarse, uniformly distributed, distinctly larger than those on pronotum.

Ventrite 1 posteriorly medially arcuate, ventrite 2 at middle narrower than both sides ( Fig. 3g). Ventrite 6 posteriorly arcuate. Abdominal postcoxal lines incomplete, merged with posterior margin of ventrite 1 with short oblique associate lateral lines ( Fig. 3g), area enclosed by the lines finely and densely punctate, irregularly distributed in anterior margin, broadly smooth along the lines; ventrite 1 with fine and sparse punctures at middle, uniformly distributed ( Fig. 3g).

Male genitalia. Penis slender and long, penis capsule with long inner arm and short outer arm ( Fig. 3h), apex of penis slightly curved with a little membranous appendage ( Fig. 3i); tegmen with penis guide subtriangular, widest at base, narrowed to an acute tip in lateral view, slightly shorter than parameres ( Fig. 3j); in inner view, penis guide fusiform, constricted at base, widest at middle, apex pointed ( Fig. 3k); parameres elongate oval with bluntly rounded apices in lateral view, with few setae at outsides ( Figs 3j–k).

Female. Head black, antennae and mouthparts yellow, except tip of mandibles dark brown and labrum black ( Fig. 3f). Pronotum all black ( Figs 3d–f). Scutellar shield black. Elytra black with apical half gradually faded from black to dark brown ( Figs 3d–f). Prothoracic hypomeron yellowish brown, prosternum all black. Mesoventrite, metaventrite black, and elytral epipleurae dark brown with black margin. Legs darken and uneven with femora blackishish brown, tibiae dark brown, tarsi yellowish ( Figs 3e–f).

Material examined. Holotype, male, No. SCAU (E) 17588, CHINA: Guangdong: Feifeng Mountains, Dafushan Forest Park, Panyu District , Guangzhou City , Guangdong Province, 10.III.2022, Malaise Trap, Liu ZW leg. ( SCAU) . Paratypes. Guangdong : 2♂ 3♀, Feifeng Mountain, Dafushan Forest Park, Panyu District , Guangzhou City , Guangdong Province, 23.I.2022, Malaise Trap, Liu ZW leg. ; 1♂ 2♀, Feifeng Mountain, Dafushan Forest Park, Panyu District , Guangzhou City , Guangdong Province, 12.X.2021, Malaise Trap, Liu ZW leg. ; 1♂ 2♀, Feifeng Mountain, Dafushan Forest Park, Panyu District , Guangzhou City , Guangdong Province, 9.XII.2021, Malaise Trap, Liu ZW leg. ; 1♀, Feifeng Mountain, Dafushan Forest Park, Panyu District , Guangzhou City , Guangdong Province, 10. V .2022, Malaise Trap , Liu ZW leg. ( SCAU) .

Distribution. China (Guangdong).

Etymology. The specific epithet is given after Dafushan Forest Park, the type locality of this species.

Remarks. This species possesses some distinctive characteristics to all known Chinese species of Diomus : posterior margin of ventrite 1 medially arcuate, ventrite 2 at middle narrower than both sides; abdominal postcoxal lines with short oblique associate lateral lines; parameres bearing setae at outsides.