Nossidium koreanum sp. nov.

(Figs 1A–B, 2, 5: circle)

Diagnosis. The adult of Nossidium koreanum is very similar to the western Palaearctic Nossidium pilosellum (Marsham, 1802) . It can be distinguished by the shape of the aedeagus (round apical tip, shorter paramere with less number of setae) and stout, globular spermatheca. It is also similar to the European Nossidium flachi Ganglbauer, 1898 but differs by being on average slightly smaller and with stouter, less elongate body form, and by its broader intermesocoxal process and more evenly curved metaventral lines (Fig. 2G). In addition, we compared N. koreanum to several Nearctic Nossidiine taxa, described as well as undescribed, without finding any correspondance.

Description. Body length 0.95–1.05 mm, width 0.52–0.56 mm; oval, convex; color brown, evenly punctuate with pale yellow pubescence. Antennomeres I–II light brown, III–XI dusky yellow (Figs. 1A–B).

Head. Broad, rounded; weakly and sparsely punctuate. Eyes large; distance between eyes in ventral view 0.22 mm. Antennal length 0.46 mm; antennomeres I–II large, stouter than others; III short, cone-shaped; IV–VIII long, distally weakly dilated; IX–XI clavate, basal half of seta darker; IX ovoid; X basally dilated by three fourths; XI ovoid (Fig. 2A).

Thorax. Pronotum length 0.31 mm, width 0.55 mm; widest slightly in front of base; lateral margin smooth, not serrate; surface shining, rather weakly, evenly punctuate with pubescence; posterior margin sinuate (Fig. 2B). Scutellum small, triangular (Fig. 2C).

Wings. Elytral length 0.69 mm, long, complete; evenly punctuate with pubescence; lateral and posterior margin rounded (Fig. 2E). Hindwing blade wide, membranous; anterior petiolar margin setose on distal two thirds (Fig. 2D).

Meso-, Metaventrite. Mesoventrite anteriorally with collar and keel; medial collar extension and keel weakly developed; laterally of mesocoxae, mesopleural [anterior] suture rather straight, directed obliquely anterad, metaventral [posterior] line rather straight, distally gently curved posterad; mesoventrite medially as long as metaventrite (Fig. 2G).

Abdomen. Abdominal sternite I anteromedially with prominent knob fitting to metaventral [intermetacoxal] condyle (Figs. 2G, J–K). Male abdominal sternite VI rounded, female somewhat angled (Figs. 2J–K). Male tergite X smoothly triangular, female posterior margin sexdentate (Figs. 2H–I).

Legs. Procoxae contiguous. Mesocoxae separated by broad process. Metacoxae short, wide, almost contiguous, only separated by an intermetacoxal condyle (Figs. 2B, G).

Male genitalia. Aedeagus elongate, somewhat flattened, slightly asymmetric, basal foramen skewed, apex obtusely rounded; parameres each with two setae, apical one longer (Fig. 2L).

Female genitalia. Spermatheca small, globular, mushroom-shaped part short and stout (Fig. 2M).

Material examined (n=20, 9♁♁ 11♀♀).

Holotype (deposited in NIBR), ♁ (dry), Korea: Gyeongbuk Prov. Seonghyeon-ri, Yongmun-myeon, Yecheon-gun, 04.V.2019, 36°40′48.0″N 128°25′09.0″E, 134 m, sifting leaf & soil litter, U.-J. Byeon.

Paratypes (deposited in CBNUIC), 1 ♁ 1♀ (1♁, slide; 1♀, dry), same data as in holotype; 2♁♁ (dry), Korea: Chungbuk Prov. 1061-29, Chopyeong-ro, Chopyeong-myeon, Jincheon-gun, 31.III.2021, 36°48'47.2"N 127°31'13.7"E, 92 m, sifting leaf& soil& deadwood debris, J.-I. Shin, J.-W. Kang; 1 ♁ 5♀♀ (4♀♀, dry; 1♁ 1♀, slide), Korea: Chungbuk Prov. 182, Dangdongjanghyeon-ro, Daegang-myeon, Danyang-gun, 19.III.2021, 36°55'39.0"N 128°22'30.0"E, 360 m, sifting leaf & soil litter, T .- Y. Jang, Y.-J. Choi, M.-H. Song; 1♁ (dry), Korea: Chungbuk Prov. Jagwangsa, Mt. Worak, 1560-35, Mireuksonggye-ro, Hansu-myeon, Jecheon-si, 28. V .2020, 36°52′52.0″N 128°05′05.0″E, 275 m, sifting leaf & soil litter, M.-H. Song, U.-J. Byeon; 1♀ (dry), same locality, 09. VI .2021, 36°52'52.0"N 128°05'10.0"E, 276m, sifting leaf& soil &deadwood debris, J.-I. Shin,M.-H.Song; 1♀ (card mounted), same locality, 15.VII–29.VIII.2022, 36°52'53.3"N 128°05'13.8"E, 292 m, F.I. T ., J.-I. Shin, U.-J. Hwang; 1♁ 1♀ (in 95% EtOH), Korea: Gangwon Prov. 535, Woran-gil, Anheung-myeon, Hoengseong-gun, 29.IV.2022, 37°23'01.7"N 128°09'44.3"E, 608 m, sifting leaf & soil litter, J.-I. Shin, M.-H. Song; 1 ♁ 1♀ (dry), Korea: Gyeongbuk Prov. 164, Winneungnae-gil, Yongmun-myeon, Yecheon-gun, 20.IX.2021, 36°42'43.5"N 128°25'27.9"E, 355 m, sifting leaf & soil litter, U.-J. Byeon; 1♁ (dry) , Korea: Gyeongbuk Prov. Cheongnyeo-ro, Unmun-myeon, Cheongdo-gun, 02.VII.2021, 35º45'18.9''N 128º56'41.5''E, 251 m, sifting leaf & soil litter, M.-H. Song, U.-J. Byeon, J.-I. Shin ; 1♀ (dry), Korea: Jeonbuk Prov. Yeobang-ri, Seongsan-myeon, Gunsan-si, 03.VIII.2021, 36°00′38.1″N 126°47′00.9″E, 175 m, sifting leaf & soil litter, J.-W. Kang, J.-W. Kim .

Distribution. South Korea (Fig 5: circle).

Etymology. This species was named after the type locality: Korea.