ZOOTAXA ISSN 1175-5326 (print edition) ISSN 1175-5334 (online edition) Accepted by J. Jennings: 6 Aug. 2019; published: 3 Sept. 2019 241 Zootaxa 4664 (2): 241–250 https://www.mapress.com/j/zt/ Copyright © 2019 Magnolia Press Article https://doi.org/10.11646/zootaxa.4664.2.6 http://zoobank.org/urn:lsid:zoobank.org:pub:AE9CF31B-7E1E-4E0D-B101-BA71A2BDEB48 A new genus of the subfamily Hybrizontinae (Hymenoptera: Ichneumonidae) from Japan YU HISASUE 1 & KAZUHIKO KONISHI 2 1 Entomological Laboratory, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, 744, Motooka, Nishi- ku, Fukuoka, Fukuoka, 819-0395, Japan. E-mail: hybrizonist@gmail.com 2 Laboratory of Environmental Entomology, Faculty of Agriculture, Ehime University, Tarumi 3-5-7, Matsuyama, Ehime 790-8566, Japan. E-mail: konishi.kazuhiko.eb@ehime-u.ac.jp Abstract Neohybrizon gen. nov. is described from Japan (type species: Neohybrizon mutus sp. nov.). This new genus is characterized by much reduced mouth parts, long mesoscutum, absence of epicnemial carina, depressed posterocentral area of mesoscutum, slender stigma, short RS+M of fore wing, entirely straight M of fore wing, slender hind wing, long hind femur which is over 5.5 × as long as trochanter, and using the ant Myrmica kotokui Forel, 1911 as its host. A key to genera of Hybrizontinae is also provided. Key words: Neohybrizon, new species, taxonomy Introduction Hybrizontinae, a small subfamily of Ichneumonidae, is distributed over the Holarctic region and includes 13 extant species in three genera, Ghilaromma, Hybrizon, and Ogkosoma (Yu et al. 2012; Madl 2013). This subfamily had been treated as a member of Braconidae (e. g. Foerster 1862; Capek 1970; van Achterberg 1976) or considered to be a separate family (e. g. Tobias 1988), because of its peculiar characteristics such as wing venation. Currently, this taxon is treated as a subfamily of Ichneumonidae, because the second metasomal tergite is not fused with the third tergite, and vein 1r-m of the hind wing is opposite or apical to the separation of R1 and Rs (e.g. Gauld 1984). In Ich- neumonidae, Hybrizontinae is placed in the ophioniformes (Quicke et al. 2009; Quicke, 2015; Broad et al. 2018). The biology of Hybrizontinae has been for a long time only known that Ogkosoma cremieri (Romand, 1838) attacked larvae of Lasius fuliginosus (Latreille, 1798) (Formicidae, Formicinae) when they were carried by workers (Cobelli 1906), and Hybrizon buccatus (de Brébisson, 1825) pupae were found in same chamber with ant pupae in the nest of L. alienus (Foerster, 1850) (Donisthorpe 1913). Recently, Gómez Durán & van Achterberg (2011) re- ported the movie of oviposition behavior of H. buccatus and Komatsu & Konishi (2010) photographed the behavior of O. cremieri and a species which could not be placed in any known genera. In this paper, we describe the species which was reported by Komatsu & Konishi (2010) as Gen. sp. and establish a new genus for the species. Materials and methods Materials used in this paper will be deposited in Ehime University Museum, Japan (EUMJ), Kanagawa Prefectural Museum of Natural History, Odawara, Japan (KPMNH), Institute for Agro-Environmental Sciences, NARO, Tsu- kuba, Japan (NIAES), Osaka Museum of Natural History, Osaka, Japan (OMNH), Laboratory of Systematic Ento- mology, Hokkaido University, Sapporo, Japan (SEHU), Tochigi Prefectural Museum, Utsunomiya, Japan (TPM), American Entomological Institute, Utah, USA (AEI), Natural History Museum, London, UK (BMNH), Zoological Institute of the Russian Academy of Sciences, St. Petersburg, Russia (ZI). Images were taken with a Nikon D90 digital camera attached to a Leica MZ16 stereomicroscope or a Nikon