Peromitra multisetalis (Colyer, 1966)

(Figs. 1F, 1G, 2M–O, 3F–J, 4M–O, 5F, 5G, 10)

Borophaga (Peromitra) multisetalis Colyer, 1966: 71 . Type locality: Kunashir Is.

Peromitra multisetalis: Nakayama & Shima, 2002: 65 (generic assignment).

Diagnosis. This species can be distinguished from the other Peromitra species by the combination of the following characteristics: ocellar region distinctly protruded; first flagellomere orange to yellow; midtibia with 4–6 strong dorsal bristles arranged in two or three pairs; hind tibia with two or three anterodorsal bristles on basal half; wing vein R 2+3 absent; hypopygium nearly symmetrical; posterior margin of hypandrium with securiform process protruded posteriorly; aedeagus with two long, extremely curved apical processes; ventral process of aedeagus with feathered apex.

Description. Male. Body length 2.40–3.23 mm (n=10). Head (Figs. 1F, 2M–O). Frons black, shiny, with three transverse rows of four long bristles and sparsely covered fine hairs; supra-antennal bristle absent; middle row of bristles nearly straight. Vertex with distinctly raised ridge along posterior margin; ocellar region (Fig. 2M–O) distinctly raised, 1.5× wider than long; anterior ocellus oval, twice wider than long, 1.5× wider than lateral ocelli, protruded anterodorsally. First flagellomere orange to yellow, subglobose. Arista brown, located subapically. Palpus yellowish brown to pale yellow, with single long apical bristle and some shorter bristles on ventral margin of apical half. Labrum and labella pale yellow, short. Thorax (Fig. 1F). Scutum and scutellum blackish brown. Posterior margin of scutum without strong prescutellar bristle between post-alar bristles. Scutellum with anterior pair of short narrow bristles and posterior pair of long strong bristles. Pleuron reddish dark brown, slightly brighter under half of anepisternum. Upper half of anepisternum covered with short setae. Legs (Figs. 1F, 4M–O). Blackish brown except fore tibia and tarsus yellowish brown, midtarsus brown. Fore tibia (Fig. 4M) with two or three (mostly two) dorsal bristles on basal half and single longitudinal row of short dorsal setulae along tibial length. Apical fore tarsomere widened, with enlarged pulvilli. Midtibia (Fig. 4N) with single dorsal longitudinal setal palisade, 4–6 dorsal bristles arranged in two or three pairs (if five bristles, then arranged in two pairs plus one most basal anterodorsal bristle) on basal half, one long anteroventral bristle, one long ventroapical spur, and two short ventroapical setae near apical spur. Hind tibia (Fig. 4O) with two dorsal longitudinal setal palisades, 2–4 (mostly three) anterodorsal strong bristles on basal half, one or two anterodorsal preapical bristle, one dorsoapical bristle, three ventroapical spurs, and some posteroapical short setae. Wing (Fig. 5F). 2.53–3.01 mm long (n=10). Costal index 0.47–0.51. Mean costal ratio 1.12:1; range 1.00–1.26:1. Costal setae of costal section II 0.08–0.13 mm long. Vein Rs with single row of short, fine setulae on dorsal face except apical one-third. Vein R 2+3 absent. Vein R 4+5 not distinctly widened. Vein M 1 slightly curved basally and nearly straight apically. Veins brown, membrane hyaline with yellow tinge. 7–10 alular setae present, 0.15–0.22 mm long. Halter black. Abdomen (Fig. 1F). Tergites blackish brown, shiny. Venter of abdomen dark brown, with single pair of rounded sternite 6. Hypopygium (Fig. 10A–D). Epandrium nearly symmetrical, dark brown; epandrial lobe dorsally fused, elongated posteroventrally on both side and widened apically, covered with some long setae basally and short, fine hairs apically (Fig. 10A–C). Hypandrium large, dark brown. Lower portion of hypandrium with single pair of lateral membranous lobe boomerang-shaped, spinulose; anteroventral portion of lateral membranous lobe not distinctly developed (Fig. 10A, C). Posterior margin of each side of hypandrium with securiform process protruded posteriorly (Fig. 10A, C); left side of posterior margin of hypandrium with hooked plate hidden behind securiform process in left view (Fig. 10A). Single pair of small anteroventral processes near basal portion of phallapodeme present, highly sclerotized (Fig. 10D). Cercus and hypoproct short, with some short hairs. Aedeagus (Fig. 10E, F). Basically tubular, consisting of dorsal tube and ventral process protruding at middle of dorsal tube. Dorsal tube curved perpendicularly, with apical half greatly elongated; extension of dorsal tube mostly membranous, greatly curved upwardly, spiral, with triangular membranous process ventrobasally; apical portion with serrated lower margin and pointed apex (Fig. 10E). Ventral process greatly elongated and curved upwardly, apical portion with narrow membrane at left side and feathery lower margin and apex (Fig. 10F).

Female. Body length 3.25–3.41 mm (n=5). Head (Figs. 1G, 3F–J). Similar to male but differed as follows: first flagellomere smaller, globose (Fig. 3F); labrum similar to male but slightly larger, triangular, with apex not sclerotized (Fig. 3G, H); labella enlarged, with ligula small, not highly sclerotized; ventral surface of each labellum with pseudotracheae extended on entire surface of labella (Fig. 3I, J). Thorax (Fig. 1G). Similar to male. Legs (Fig. 1G). Similar to male but fore tarsomere 5 not widened. Wing (Fig. 5G). Similar to male, 2.68–3.08 mm long (n=5). Costal index 0.47–0.51. Mean costal ratio 1.08:1; range 1.00–1.27:1. Costal setae of costal section II 0.09–0.11 mm long. 6–8 alular setae present, 0.17–0.19 mm long. Abdomen (Figs. 1G, 10G–I). Tergites 1–6 well developed, blackish brown. Abdominal segment 7 without any sclerite. Tergite 8 narrowed, rectangular, yellowish brown (Fig. 10G). Tergite 9 entirely developed on dorsal face of abdominal segment 9+10, oval, yellowish brown (Fig. 10G). Venter of abdomen dark brown, with only sternite 9 discernable. Sternite 9 developed on posterior half of abdominal segment 9+10, short, triangular, yellowish brown (Fig. 10H, I). Cercus small, oval, with single long hair on apex and some shorter hairs on surface.

Specimens examined. Korea: 1♂, Gyeonggi-do, Pocheon-si, Soheul-eup, Korea National Arboretum, 37°45′22″N, 127°09′48.9″E, 16.vi.2014, Malaise trap, KNA leg. (KNU) ; 5♂, Gangwon-do, Inje-gun, Buk-myeon, Hangye-ri, 38°08′46.5″N, 128°15′47.5″E, 4.vii.2018, Malaise trap, S. Nam leg. (KNU) ; 1♂ 1♀, ditto, 24.vi– 2.vii.2019, Park & Nam leg. (KNU); 3♂, Gangwon-do, Pyeongchang-gun, Yongpyeong-myeon, Nodong-ri, Nodong Valley, 37°42′31″N, 128°29′03.8″E, 16.vi–31.viii.2019, Malaise trap, M. Lee & Park leg. (KNU) ; 4♂, Gangwon-do, Chuncheon-si, Dongnae-myeon, Geodu-ri, Mt. Daeryongsan, 37°51′08″N, 127°48′22.2″E, 5–19.vii.2019, Malaise trap, J.-H. Lee leg. (KNU) ; 1♂, Daejeon, Yuseong-gu, Seongbuk-dong, 36°18′52.6″N, 127°17′23.3″E, 13.vi– 4.vii.2020, Malaise trap, Oh & Park leg. (KNU) ; 1♀, Gyeonggi-do, Yeoncheon-gun, Baekhak-myeon, Tonggu-ri, forest near Baekhak reservoir, 38°01′43.1″N, 126°55′17.1″E, 14–28.vi.2020, Malaise trap, J.-H. Lee leg. (KNU) ; 5♂ 3♀, Gangwon-do, Pyeongchang-gun, Jinbu-myeon, Mt. Odaesan, near Sangwonsa Temple, 37°47′03.9″N, 128°33′45.2″E, 15.vii–14.viii.2020, Malaise trap, J.-H. Lee leg. (KNU) ; 1♂, Chungcheongbuk-do, Danyanggun, Danyang-eup, Cheondong-ri, Mt. Sobaeksan, 36°57′31″N, 128°26′10″E, 5.vi–17.vii.2021, Malaise trap, J.- H. Lee leg. (NIBR) ; 6♂, Gyeonggi-do, Gwangju-si, Docheok-myeon, Sangnim-ri, Mt. Taehwasan, 37°18′42.4″N, 127°18′33.4″E, 8–25.vi.2021, Malaise trap, S. Shin et al. leg. (KNU) ; 1♂, Gyeonggi-do, Anyang-si, Manan-gu, Anyang-dong, Seoul National University Gwanak Arboretum, 37°25′11.6″N, 126°56′10.2″E, 8–25.vi.2021, Malaise trap, S. Shin et al. leg. (KNU) ; 1♂, Jeollabuk-do, Wanju-gun, Unju-myeon, Wanchang-ri, Mt. Daedunsan, 36°05′59.4″N, 127°18′02.4″E, 13.vi–24.vii.2021, Malaise trap, O.C. Kwon leg. (KNU) ; 1♂, Gangwon-do, Wonju-si, Panbu-myeon, Chiaksan National Recreational Forest, 37°15′03.6″N, 128°01′39.6″E, 611 m, 14.vi–3.ix.2022, Malaise trap, S. Shin et al. leg. (KNU) ; 1♂, Gangwon-do, Samcheok-si, Dogye-eup, Hwangjo-ri, Mt. Yukbaeksan, 37°13′59″N, 129°06′15″E, 859 m, 17.vi.2023, J.-H. Lee leg. (KNU) ; 1♂, Gangwon-do, Hongcheon-gun, Nae-myeon, Sambong National Recreational Forest, 37°52′03.9″N, 128°27′42.4″E, 737 m, 3–24.vii.2023, Malaise trap, S. Shin et al. leg. (KNU) .

Ecology. This species was collected widely in mountainous regions in South Korea. Adults usually appear in summer, wandering on leaves of broadleaf trees or shrubs. Detailed ecological information including larval feeding habits is largely unknown.

Remarks. The number of dorsal strong bristles on tibiae varies among the specimens from Korea, Russian specimens in Colyer (1966), and Japanese specimens in Nakayama & Shima (2002), as in Table 1. Nakayama & Shima (2002) confidently separated P. multisetalis from a similar species, P. eumimeta (Beyer, 1958), described from Myanmar, by the number of midtibial bristles (three pairs in P. multisetalis vs. two pairs in P. eumimeta). However, caution must be taken to distinguish these two species since the number of tibial bristles of P. eumimeta falls into the range of intraspecific variation of P. multisetalis (Table 1). Also, these two species have similar morphologies of ocellar region, color of antennae and hypopygium, with reference to the photograph of the holotype specimen (Fig. 13) and an illustration of P. eumimeta in Brown (1992). To clarify the identity of these two species, detailed examination of hypopygium, especially the morphology of aedeagus, is warranted because the aedeagus of P. eumimeta has not been illustrated.

Distributions. Korea (Gyeonggi-do, Gangwon-do, Chungcheongbuk-do, Daejeon, Jeollabuk-do), Russia (Far East), Japan.