Sindosium chungbukicum Jang & Sörensson & Park 2023, sp. nov.

Sindosium chungbukicum sp. nov.

(Figs 1E–F, 4, 5: square)

Diagnosis. Adult of Sindosium chungbukicum can be distinguished from other Sindosium species by weakly developed mesoventral process and long, oval, assymetrically caved spermatheca with puffed out basal tip.

Description. Body length 0.97–0.99 mm, width 0.52–0.54 mm; oval, convex; color light brown, dorsum punctuate with pale yellow pubescence. Antennomeres I–II reddish brown, III–XI dusky yellow (Figs. 1E–F).

Head. Broad, rounded; weakly, finely, very sparsely punctuate. Eyes large; distance between eyes in ventral view 0.19 mm. Antennal length 0.40 mm; Antennomeres I–II large, thicker than others; III short, cone-shaped; IV–V long, weakly dilated distally; VI–VII lengthy oval; VIII oval, short, stout; IX–XI clavate, basal half of seta darker; IX ovoid, basal half swollen; X basal two thirds swollen; XI ovoid (Fig. 4A).

Thorax. Pronotum length 0.26 mm, width 0.45 mm; widest slightly behind middle, basally narrowed; lateral margin curved, flattened and serrate; surface shining, evenly punctuate except for a small central patch; posterior margin almost straight, somewhat wider than anterior margin. Scutellum equilaterally triangular (Figs. 4B–C).

Wings. Elytra length 0.64 mm, long, complete; evenly punctuate with pubescence; lateral margin anteriorly with 4–5 denticules, each with seta; posterior margin rounded (Fig. 4E). Hindwing blade wide, membranous; anterior petiolar margin with one distinct seta, posterior margin setose on distal third (Fig. 4D).

Meso-, Metaventrite. Mesoventrite with anterior collar and keel; keel somewhat slender; laterally of mesocoxae, mesopleural [anterior] suture straight, directed obliquely anterad, metaventral [posterior] line slightly cave, distally obtusely angled, directed posterad. Mesoventrite medially shorter than metaventrite (Fig. 4G).

Abdomen. Abdominal sternite I anteromedially with prominent knob fitting to metaventral [intermetacoxal] condyle (Figs. 4G, I). Female tergite X small, semicircular (Fig. 4H).

Legs. Procoxae contiguous. Mesocoxae separated by faint process. Metacoxae short, wide, almost contiguous; separated only by an intermetacoxal condyle (Figs. 4B, G).

Male genitalia. unknown.

Female genitalia. Spermatheca length 0.17 mm, width 0.091 mm; ovally elongate, almost two times longer than wide, invaginated basally; short chord proximally of invagination; base rounded, mushroom-shaped part short and stout, apex puffed out (Fig. 4J).

Material examined (n=4, 4♀♀).

Holotype (deposited in NIBR), ♀ (dry), Korea: Chungbuk Prov. Jagwangsa, Mt. Worak, 1560-35, Mireuksonggye-ro, Hansu-myeon, Jecheon-si, 28.V.2020, 36°52′52.7″N 128°05′11.0″E, 277 m, sifting leaf & soil litter, J.-Y. Kang, T.- Y. Jang.

Paratypes (deposited in CBNUIC), 1♀ (dry), Korea: Chungbuk Prov. 182, Dangdongjanghyeon-ro, Daegang-myeon, Danyang-gun, 22. V.2020, 36°55′38.9″N 128°22′30.9″E, 348 m, sifting leaf & soil litter, M.-S. Jang, J.-W. Kim; 1♀ (slide), same locality, date and method, T.- Y. Jang, Y.-J. Choi; 1♀ (dry), Korea: Chungbuk Prov. Jagwangsa, Mt. Worak, 1560-35, Mireuksonggye-ro, Hansu-myeon, Jecheon-si, 25. V.2021, 36°52′52.4″N 128°05′05.5″E, 241 m, sifting leaf & soil litter, J.-W. Kang, Y.-J. Choi, M.-H. Song.

Distribution. South Korea (Fig 5: square).

Etymology. This species was named after the type locality: Chungbuk province of South Korea.