Dichetophora koreana sp. nov.

(Figs. 1–2)

Diagnosis. Body ground color yellow; occiput whitish yellow with numerous setae; 1 black spot at base of anterior fronto-orbital seta; all tarsi brownish black; wing with numerous square hyaline spots; 2 pairs of scutellar setae; apex of the cercus narrowly protruded, with some setae; knifelike surstylus long, narrow, ventral apex asymmetrically rounded, knob-like projection at basal margin bulge in lateral view.

Description (male). Head (Fig. 1A–C). Yellowish and shining; mid frontal stripe reaching anterior margin of frons; narrow fronto-orbital margin silver; ocellar triangle brown; occiput yellow with darker median area bordered by narrow whitish pruinescent stripes and with setae laterally; cluster of stout setae in middle of median area; round black spot at base of anterior fronto-orbital seta; face yellowish brown with white pruinescence; orbito-antennal spot large, black; lunule shining brown with black setulae; antenna porrect, yellowish brown; postpedicel slightly shorter than pedicel, covered with whitish setulae; arista yellowish white pubescent; pedicel about 6 times as long as scape; scape yellow, with setae on dorsal margin; gena white from ventral margin of eye halfway to oral margin, yellow in ventral half; palpus yellow with long black setae; 2 fronto-orbital, 1 postocellar, 1 inner vertical, and 1 outer vertical setae; ocellar seta absent.

Thorax (Fig. 1C–D). Yellowish brown; scutum covered with white setulae and short black setae; 2 dark-brown median vittae and 2 broken dark brown lateral vittae on scutum; 1 dorsocentral, 2 scutellar, 1 postpronotal, 1 supraalar, 2 postalar, and 2 notopleural setae present; presternum, anepisternum, anepimeron, meron, and katatergite bare, katepisternum entirely covered with black setulae; anterior and posterior spiracles yellow.

Wing (Fig. 1E). Yellowish with numerous poorly defined yellowish square and sub-square spots; most veins yellowish; posterior 2/3 of crossvein r-m and adjacent area of vein M 1 with large subtriangular black spot, crossvein dm-m slightly S-shaped; apical half of vein R 4+5 blackish; costal vein hyaline yellow; 6–7 black spots in cell r 1; alula and anal cells immaculate; pale black spots in cell m 4; 2 pale black spots on cell br; veins R 4+5 and M 1 very slightly convergent at apex; halter yellow.

Leg (Fig. 1C). Generally yellowish brown; all tarsi black and brown; all coxae with cluster of long setae at ventral apex; fore and mid coxae yellowish white; mid coxa yellow with cluster of long setae at ventral apex; hind coxa brown with 1 anterodorsal seta and with cluster of long setae at ventral apex; fore femur yellow basally, becoming brown apically; mid femur with dorsal spines on apical 1/3; hind femur with dorsal spines; fore and hind femora darkened at the dorsal apex; foretibia darkened at apex; hind tibia with blackish annulation at apex.

Abdomen (Fig. 1C, Fig. 2). Yellowish brown; tergites 2–4 darkish brown with black linear lateral stripe; sternites 2–4 with long setae at the posterior apex; sternite 5 divided, with cluster of short setae and 4–5 pairs of long setae on each side; syntergosternite 6 asymmetric, the left side larger than the right side in posterior view; syntergosternite 7+8 setose on posterior half; epandrium suboval in posterior view and taller than syntergosternite 7+ 8 in lateral view; apex of the cercus narrowly protruded, with some setae; knifelike surstylus long, narrow, ventral apex asymmetrically rounded; knob-like projection at basal margin setulose, slightly protruding and bulge in lateral view; posterior process of pregonite sharply pointed; distiphallus asymmetric, left side with two pointed structures, right side with single small rounded structure with hyaline membranous center in posterior view, one curved structure in left view; basiphallus trapezoidal in posterior view.

Female. Similar to male but larger, with all body patterns more sharply defined than in male; postpedicel with pale black spot; veins hyaline yellow except posterior half of vein R 4+5 vein black; apex of fore tibia darker than in male; mid femur with brown annular ring at distal apex; tarsus all black; sternites with inner brown and outer yellow stripes; tergite 10 and cercus with pairs of long setae, distinctly separated from sternite 10.

Body length: male: 10.3–10.4 mm, female: 12.4–12.6 mm.

Wing length: male: 8.5–8.6 mm, female: 10–11 mm.

Type material. Holotype: male, Mt. Guryongsan, Sangdong-eup, Yeongwol-gun, Gangwon-do, 37°07′16″N 128°48′54″E, 24.VII.2018, S.J. Suh . Paratypes: 1 female, Mt. Duwibong, Nam-myeon, Jeongseon-gun, Gangwondo, 37°14′10″N 128°45′35″E, 02.IX.2018, S.J. Suh ; 1 male, Mt. Majeongsan, Gunwi-eup, Gunwi-gun, Gyeongsangbuk-do, 36°13′38″N 128°34′35″E, 27. VI.2016, S.J. Suh ; 1 female, Sango-ri, Hwabuk-myeon, Sangju-si, Gyeongsangbuk-do, 36°32′17″N 127°53′54″, 25. VI.2018, S.J. Suh ; 1 female, Mt. Cheonhwangsan, Sannae-my- eon, Miryang-si, Gyeongsangnam-do, 35°34′29″N 128°59′12″E, 30.IX.1984, S.J. Suh ; 1 female, Mt. Hwawangsan, Okcheon-ri, Changnyeong-eup, Changnyeong-gun, Gyeongsangnam-do, 35°32′46.7″N 128°32′23.9″E, 08.X.2020, S.J. Suh ; 2 females, Mt. Baekgolsan, Biin-myeon, Seocheon-gun, Chungcheongnam-do, 36°09′37″N 126°38′15″E, 05.IX.2020, S.J. Suh .

Distribution. Korea (Central and Southern, new record).

Remarks. The new species, Dichetophora koreana sp.nov., is similar to D. japonica and D. meleagris in having two pairs of scutellar setae (Fig. 1D). However, this species is distinguished from D. japonica by the following features: body and occiput yellow, larger size (10.3–12.6 mm), different wing pattern (Fig. 1E), and different male postabdominal structures (Fig. 2). Dichetophora koreana differs from D. meleagris by the yellow femora (Fig. 1C), the shape of the knob-like projection at the basal margin of the surstylus (Fig. 2B), and the structure of sternite 5 (Fig. 2G). The new species is distinguished from the Palearctic species D. finlandica, D. kumadori, and D. obliterata by the presence of two pairs of scutellar setae (Fig. 1D) and the different structure of the sternite 5 (Fig. 2G).

Etymology. This new species has been found throughout Korea and is thus is named for its country of origin.