A review of the genera Gnathochorisis Förster and Symplecis Förster of South Korea, with notes on Korean orthocentrines (Hymenoptera, Ichneumonidae, Orthocentrinae)

Abstract

Two genera of Korean Orthocentrinae, Gnathochorisis and Symplecis, are reviewed, and keys to species of these genera are provided here. Two new species, Gnathochorisis fuscipes Humala & Lee, sp. n. and Gnathochorisis koreensis Humala & Lee, sp. n. are described from South Korea. The current state of the taxonomy of Eastern Palaearctic orthocentrines is briefly discussed.

First records of the genus Gnathochorisis Förster (Hymenoptera, Ichneumonidae, Orthocentrinae) in the Oriental region

“…nov. can be distinguished from the majority of species of the genus by the lack of closed areolet. From the other two similar known species without areolet (G. flavipes and G. fuscipes Humala & Lee, 2016), the new species differs in the strongly transverse head, and stronger apophyses on propodeum. From the East Palaearctic G. fuscipes, the new species differs in having a narrow face with width 0.45 times head width at the level of antennal sockets (0.51-0.53 times in G. fuscipes), slenderer flagellum with first flagellomere about 4.7 times as long as wide (3.9 times in G. fuscipes), predominantly yellow hind legs (hind coxa dark brown in G. fuscipes), and a shorter ovipositor -0.8 times as long as first tergite (as long as first tergite in G. fuscipes).…”

“…Later Acroblapticus and Laepserus were synonymized with Gnathochorisis (Aubert 1966(Aubert , 1969, and Blapticus species were divided between Gnatnochorisis and Symplecis Förster, 1869(van Rossem 1981. Western Palaearctic species of Gnathochorisis were revised by van Rossem (1981van Rossem ( , 1987; three more species have been described from the Eastern Palaearctic (Humala 2007;Humala et al 2016;Watanabe 2020). In North America, this genus has been revised by Dasch (1992); he reported eight species of the genus for the Nearctic, two of them with Holarctic distribution.…”

Laboratory evaluation of Orthocentrus brachycerus (Hymenoptera: Ichneumonidae), as a potential biological control agent in mushroom cultivation

“…It is presumed that they will all be koinobiont endoparasitoids of primitive dipteran hosts in the superfamily Sciaroidea, some of which eat fungi or bacteria during their larval stages; thus, Orthocentrinae is expected to be a natural enemy of mushroom cultivation pests (Delobel & Matile, 1976;Humala et al, 2016Humala et al, , 2017. Orthocentrus brachycerus and S. bicingulata have also been reported from Korea (Humala et al, 2016(Humala et al, , 2020, and species of Orthocentrus and Symplesis are widely distributed in China, Europe, South America and throughout much of the world (Humala, 2007;Humala et al, 2016Humala et al, , 2020Watanabe, 2016Watanabe, , 2018Watanabe, , 2019aWatanabe, , 2019bWatanabe et al, 2020;Yu et al, 2016). Since various edible mushrooms, including shiitake, are cultivated in these countries, this group of wasps shows promise for biological control in mushroom cultivation on a wider scale.…”

A review of the genus Orthocentrus Gravenhorst (Hymenoptera, Ichneumonidae, Orthocentrinae) from South Korea

“…The genera most rich in species in Russian Far East are Eusterinx Förster (13 species known), Megastylus Schiødte (8 species), Orthocentrus Gravenhorst, 1829 (4 species), Stenomacrus Förster, 1869 (2 species), Plectiscidea Viereck, 1914 (9 species), and Proclitus Förster, 1869 (9 species), but many genera need to be revised and these number are a poor reflection of actual diversity. South Korean orthocentrines are poorly known (Humala et al 2016). Eighteen Orthocentrinae genera have been found to occur in South Korea: Batakomacrus Kolarov, 1986, Neurateles Ratzeburg, 1848, Orthocentrus Gravenhorst, Picrostigeus Förster, 1869, Stenomacrus Förster, Plectiscus Gravenhorst, 1829, Aperileptus Förster, 1869, Apoclima Förster, 1869, Dialipsis Förster, 1869, Entypoma Förster, 1869, Eusterinx Förster, 1869, Gnathochorisis Förster, 1869, Helictes Haliday, 1837, Megastylus Schiødte, 1838, Pantisartrus Förster, 1871, Plectiscidea Viereck, Proclitus Förster, and Symplecis Förster, 1869.…”

“…All these genera are entirely or predominantly Holarctic, and many of them are abundant and species-rich genera. Recently the Korean species from the genera Gnathochorisis (5 species), Symplecis (2 species) and Eusterinx (9 species) were reviewed (Humala et al 2016(Humala et al , 2018, and a review of the genera Megastylus and Helictes is in process (Choi et al in prep.). However, the majority of Orthocentrinae genera have not been taxonomically treated yet, including Stenomacrus and Plectiscus, rich in species in the local fauna.…”