Neanastatinae Kalina is a small subfamily in Eupelmidae, consisting of four extant genera (Eopelma Gibson, Lambdobregma Gibson, Metapelma Westwood, and Neanastatus Girault) and four extinct genera (Aspidopleura Gibson, Brevivulva Gibson, Neanaperiallus Gibson, and Propelma Trjapitzin). Metapelma, with 39 species, is the second largest group after Neanastatus, with 45 species, in the subfamily. Some species of Metapelma are known as parasitoids of xylophagous beetles, but hosts of many species are yet to be known.

The genus Metapelma is known from all biogeographic regions, and only three species are recorded from the eastern Palearctic region (China and Russian Far East): Metapelma beijingensis Yang (China), M. pacificum Nikol’skaya (Russian Far East), and M. zhangi Yang (China). However, it has never been known from Korea and Japan until now (Noyes, 2016). In this paper, two species of Metapelma are newly recognized from South Korea. Diagnoses and images of the two species are provided, along with a key to South Korean species

Materials and Methods

Specimens used in this study were collected by malaise trapping, and they are deposited in the Laboratory of Animal Systematics, Yeungnam University, Gyeongsan, South Korea.

Specimens were examined with a stereomicroscope of LOMO and photographed with an AxioCam MRc5 camera and Plan Apo S 1.5× FWD 30 mm objective lens attached to a SteREO Discovery V20 stereomicroscope (Zeiss, Germany). Modular Dome Illumination System (Kawada and Buffington, 2016) was used when the images were taken. Serial images were combined using Extended Focus program of AxioVision SE64 software and digitally retouched using Adobe Photoshop CS6.

Acronyms used in this paper are as follows: MT, malaise trap; NWCF, Northwestern College of Forestry, Yangling 712100, Shaanxi, China; YNU, Yeungnam University, Gyeongsan, South Korea; ZISP, Zoological Institute of Russian Academy of Sciences, St. Petersburg, Russia; TS, Type Species; TL, Type Locality; TD, Type Depository; GW, Gangwon-do; GG, Gyeonggi-do; GB, Gyeongsangbuk-do; GN, Gyeongsangnam-do.

Morphological terms follow Gibson (1989): OOL, distance between a posterior ocellus and inner orbit; POL, distance between the posterior ocelli; LOL, distance between the anterior and a posterior ocellus; MPOD, maximum diameter of a posterior ocellus; cc, costal cell; mv, marginal vein; pmv, postmarginal vein; stv, stigmal vein.

Systematic accounts

Family Eupelmidae Walker, 1833 벼룩좀벌과

Subfamily Neanastatinae Kalina, 1984 납작벼룩좀벌아과(신칭)

Genus MetapelmaWestwood, 1835 큰납작벼룩좀벌속(신칭)

MetapelmaWestwood, 1835: 69. TS: Metapelma spectabile Westwood.

Halidea Förster, 1856: 31. TS: Halidea nobilis Förster.

Diagnosis. Head elongated oval-shaped in lateral view, but almost rounded in frontal view; with frons broadened, but gena and malar space relatively short; scrobes separated as vertical depression shortly above each torulus. Mesosoma with pronotum subtriangular in dorsal view; mesoscutum with a distinct longitudinal parapsidal line; scutellum not divided medially by a longitudinal sulcus; acropleuron not extended to metapleuron; mesotibia with a row of pegs, and mesotarsus with one or two rows of pegs; hind leg with femur and tibia distinctly compressed; tibia with white spot basally in most species. Ovipositor sheath distinctly extended (modified from Gibson, 1989).

Key to South Korean species of MetapelmaWestwood, 1835

1. Head and mesosoma mostly metallic green. Head in dorsal view with interocular distance about 0.27-0.29× head width. Frons with irregularly and transversely areolate-rugose (Fig. 1D). Ovipositor sheath distinctly shorter than gaster, at most about half length of gaster (Fig. 1A). ····················· ·························································M. beijingensis Yang

- Head and mesosoma mostly metallic blue. Head in dorsal view with interocular distance about 0.37× head width. Frons with distinctly meshlike coriaceous-reticulate (Fig. 2D). Ovipositor sheath distinctly longer than gaster (Fig. 2A). ··· ··················································· M. pacificum Nikol’skaya

Metapelma beijingensisYang, 1996 큰납작벼룩좀벌(신칭) (Fig. 1A-F)

Metapelma beijingensisYang, 1996: 237-239. Holotype: ♀, TL: Beijing, China; TD: NWCF.

Diagnosis. Female (habitus: Fig. 1A). Body length 4-6.5 mm, excluding ovipositor. Head (Fig. 1C, D) primarily bright green, frons and vertex dark golden-green to reddish-coppery, and between scrobes green, lower face bright golden-green with coppery luster; vertex areolate-rugose to frons irregularly and transversely areolate-rugose; with white setae hairlike to slightly lanceolate; in dorsal view with interocular distance about 0.27-0.29× head width; OOL: POL: LOL: MPOD = 0.6-0.7: 1.0: 1.0: 1.0. Scape metallic green with golden lusters. Pronotum (Fig. 1F) entirely dark violaceous, but posterior margin purple to golden-green laterally; entirely meshlike coriaceous-imbricate. Mesoscutum (Fig. 1F) bluish-green with notaular line and parapsidal lines dark except anterior region blue to violaceous; meshlike coriaceous-imbricate to coriaceous posteriorly. Acropleuron (Fig. 1E) bright golden-green with greenish-blue, coppery and purple lusters in part; meshlike coriaceous-imbricate. Fore wing (Fig. 1B) hyaline to slightly dark brown with distinct dark infuscate area under stigma vein; with cc: mv: pmv: stv = 5.3-5.9: 2.4-2.5: 3.3-3.7: 1.0. Scutellum (Fig. 1F) mostly dark violaceous to purple except posterior margin golden to metallic green; reticulate-imbricate to meshlike reticulate posteriorly. Metatibia (Fig. 1A) dark except basal one-third white. Gaster (Fig. 1A) slightly shorter than mesosoma; ovipositor sheath less than half of gaster.

Male. Unknown.

Material examined. SOUTH KOREA. GW: 1♀, Yensei Univ., Maeji-ri, Heungeop-myeon, Wonju-si, N37°16′54.49″ E127°53′54.54″, 29.v.-5.vii.2015 (M.T.), H.Y.Han; GG: 1♀, Mt. Ungilsan, Songchon-ri, Choan-myeon, Namyangju-si, N37°34′43.3″ E127°18′37.5″, 27.v.-10.vi.2009 (M.T.), J.O.Lim; GB: 1♀, Yeonhwa 2 bridge, 207, Jwaseok-ri, Dansan-myeon, Yeongju-si, N36°59′38.7″ E128°34′51.5″, 6.viii.-8.ix.2016 (M.T.), Y.J.Kim; 2♀, Namsan-ri, Hyeongok-myeon, Kyeongju si, 18.vii.-25.viii.2005 (M.T.), J.T.Man; 1♀, ditto, 2.ix.-8.ix. 2005 (M.T.), J.T.Man.

Distribution. South Korea (new record), China (Beijing).

Biology. Yang (1996) reported that M. beijingensis is probably a larval and pupal parasitoid of Scolytus schevyrewi Semenov (= S. seulensis Murayama) on Prunus persica (L.) Batsch and P. dulcis (Mill.) D.A.Webb (= P. amygdalus Batsch).

Remarks. Yang (1996) mentioned that the length of the ovipositor sheath of M. beijingensis is less than one-third the length of the metasoma and the basitarsus of the mid leg is black. However, the length of the ovipositor sheath of our specimens is less than half of the metasoma and the basitarsus of the mid leg is white. This differences suggests intraspecific variation related with area.

Metapelma pacificum Niko’skaya, 1952 긴꼬리큰납작벼룩 좀벌(신칭) (Fig. 2A-F)

Metapelma pacifica Niko’skaya, 1952: 486. Holotype: ♀, TL: Primor’ye Kray, Russia; TD: ZISP.

Diagnosis. Female (habitus: Fig. 2A). Body length 8-11.3 mm, excluding ovipositor. Head (Fig. 2C, D) primarily metallic blue except frons U-like dark purple medially to golden luster laterally, and vertex also similar color to frons but anchor-like pattern; apical half of lower face purple with blue and golden spot in part (Fig. 2C, D); vertex transversely coriaceous to frons meshlike coriaceous-reticulate; with white setae hairlike to slightly lanceolate; in dorsal view with interocular distance about 0.37× head width; OOL: POL: LOL: MPOD = 0.8-0.9: 1.3-1.4: 1.4-1.6: 1.0. Scape dark except anterior half brown. Pronotum (Fig. 2F) entirely dark with variably bluish or violaceous medially and purplish or coppery posteriorly; shallowly coriaceous-imbricate. Mesoscutum (Fig. 2F) mostly dark greenish-blue except along inner parapsidal line and inner margin adjacent to axillae golden green; entirely meshlike coriaceous. Acropleuron (Fig. 2E) with anteroventral region metallic blue to posterodorsal region purple; meshlike reticulate anteriorly to coriaceous-imbricate posteriorly. Fore wing (Fig. 2B) hyaline to brown with inconspicuous dark infuscate under stigma vein; with cc: mv: pmv: stv = 5.5-5.6: 2.6-2.9: 4.0: 1.0. Scutellum (Fig. 2E) dark purple except anterior margin blue to admargin greenish-blue but laterally and posteriorly golden to golden-green. Metatibia (Fig. 2A) reddish to dark except basal about two-fifth white. Gaster (Fig. 2A) slightly longer than mesosoma; ovipositor sheath distinctly longer than gaster.

Male. Unknown.

Material examined. SOUTH KOREA. GB: 1♀, Namsan-ri, Hyeongok-myeon, Kyeongju-si, 28.vii.-11.viii.2005 (M.T.), J.T.Man; 1♀, ditto, 18.vii.-25.viii.2005 (M.T.), J.T.Man; GN: 1♂, Grand Park, Ok-dong, Nam-gu, Ulsan-si, N 35°15′32.08″ E127°29′55.56″, 23.vii.-18.viii.2013 (M.T.), N.S.Bang.

Distribution. South Korea (new record), Russia (Primor’ye Kray).

Biology. Unknown.