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Orthocentrinae, a subfamily of small-sized parasitoids belonging to the family Ichneumonidae, was first described by Förster (1869). Most orthocentrine species are known to be koinobiont endoparasitoids of dipteran hosts of the superfamily Sciaroidea. South Korean Orthocentrinae are poorly known however recently South Korean species of the genera Aperileptus (3 species), Apoclima (1 species), Dialipsis (1 species), Eusterinx (9 species), Gnathochorisis (5 species), Orthocentrus (26 species), Pantisarthrus (1 species), Picrostigeus (1 species), Plectiscidea (3 species), Proclitus (1 species), and Symplecis (2 species) were reviewed (Choi et al., 2014;Choi and Lee, 2018, 2020a, 2020b;Humala et al., 2016, 2018, 2020). StenomacrusFörster, 1869 is a large genus comprising 73 valid species worldwide, and mainly reported from Western Palaearctic and Nearctic regions, with only six species have been distributed in the Eastern Palaearctic (Yu et al., 2016). This genus is newly recorded in South Korea for the first time, and Stenomacrus deletus (Thomson, 1897) is reported new to the Eastern Palaearctic region.
In this paper, the new record of Stenomacrus deletus from South Korean fauna, as well as its diagnosis and photos, are provided.
Materials and Methods
Images were captured with an AxioCam MRc5 camera attached to a stereo microscope (Zeiss SteREO Discovery, V20; Carl Zeiss, Gttingen, Germany), processed using the Axio- Vision SE64 software (Carl Zeiss), and optimized with a Delta imaging system (i-solution, IMT i-Solution Inc. Vancouver, Canada). The morphological terminology generally follows that of Gauld (1991). The examined specimen is deposited in the Daegu National University of Education (DNUE), Daegu, South Korea.
Systematic Accounts
Family Ichneumonidae Latreille, 1802 맵시벌과
Subfamily Orthocentrinae Förster, 1869 긴뺨자루맵 시벌아과
Genus StenomacrusFörster, 1869 얼굴긴뺨자루맵시 벌속(신칭)
Diagnosis. Clypeus not angulate medially and hardly incurved apically; mandible with small tooth on inner edge; propodeum usually with posterior transverse and median longitudinal carinae (Broad, 2010).
Host. [Diptera] Sciaridae: Bradysia confinis; Gracillariidae:Cameraria ulmella; Lasiocampidae:Dendrolimus albolineatus, Dendrolimus sibiricus; Noctuidae:Trichosia sinuata; [Coleoptera] Chrysomelidae:Psylliodes chrysocephala (Yu et al., 2016).
Redescription. Australia, Austria, Belarus, Belgium, Bulgaria, Canada, Czech Republic, Denmark, Faeroe Islands, Finland, France, Germany, Greece, Greenland, Grenada, Hungary, Ireland, Israel, Jan Mayen Island, Latvia, Lithuania, Madeira Islands, Netherlands, Norway, Poland, Romania, Russia, Reunion, South Korea (new record), Spain, St. Vincent, Sweden, Switzerland, Turkey, U.S.A., Ukraine, United Kingdom (Yu et al., 2016).
Stenomacrus deletus (Thomson, 1897) 미소얼굴긴 뺨자루맵시벌(신칭) (Fig. 1)
Orthocentrus deletus Thomson, 1897: 2442. Lectotype: female; type locality: Sweden; type depository: ZI (Zoologiska Institutionen, Helgonavägen, Lund, Sweden).
Redescription. Female. Body 2 mm; fore wing 1.5 mm. Head with long hairs, width 1.56 times as long as height in frontal view. Inner orbits convergent upward (Fig. 1B). Face shiny and sparsely punctate; clypeus small and separated from weak groove, apical margin of clypeus round. Malar space with distinct carina, 5.5 times as long as basal width of mandible (Fig. 1B). Temple shiny, 1.4 times as wide as eye in lateral view. Antenna with 19 flagellomeres and dense hairs; scape long, with maximum length 2.14 times as long as first flagellomere. Pronotum shiny with epomia, sparsely punctate. Mesoscutum with dense hairs; notaulus indistinct (Fig. 1C). Propodeum sparsely punctate; with distinct median longitudinal carinae. Fore wing with closed areolet, second intercubitus trace (Fig. 1E). First metasomal tergite with longitudinal striae in posterior area, 1.3 times as long as second metasomal tergite. Ovipositor sheath short, 0.6 times as long as hind tibia, with long hairs.
Color. Generally yellowish brown to brown (Fig. 1A). Face evenly brown, upper margin of face yellow; clypeus yellowish brown; palpi and mandible pale yellow; frons and temple dark brown; antenna yellow to yellowish brown, apical flagellomeres darken. Mesosoma reddish brown to dark brown. Legs yellow. Metasomal tergites dark brown.
Material examined. South Korea: 1♀, Gangwon-do, Wonju-si, Heungeop-myeon, Maeji-ri, Yensei Univ., 37°16′54.49″N 127°53′54.54″E, 5-23.ix.2015, H.Y. Han leg. (DNUE).
Distribution. South Korea (new record), Bulgaria, Finland, France, Germany, Ireland, Israel, Lithuania, Netherlands, Poland, Spain, Sweden, United Kingdom (Yu et al., 2016).
Region. Eastern Palaearctic (new record), Western Palaearctic.
Remarks. This species is distributed in the Eastern Palaearctic region and South Korea for the first time here. As Aubert (1981) pointed out, a cubic head, fore wing with closed areolet, thick antennal flagellomeres.
KSAE
