Integrative taxonomy and analysis of species richness patterns of nocturnal Darwin wasps of the genus Enicospilus Stephens (Hymenoptera, Ichneumonidae, Ophioninae) in Japan
Authors: Shimizu So , Broad Gavin R. , Maeto Kaoru 
Published: November 2020

The predominantly tropical ophionine genusEnicospilusStephens, 1835 is one of the largest genera of Darwin wasps (Hymenoptera, Ichneumonidae), with more than 700 extant species worldwide that are usually crepuscular or nocturnal and are parasitoids of Lepidoptera larvae. In the present study, the Japanese species ofEnicospilusare revised using an integrative approach (combined morphology and DNA barcoding). On the basis of 3,110 specimens, 47Enicospilusspecies are recognised in Japan, eight of which are new species (E. acutusShimizu,sp. nov.,E. kunigamiensisShimizu,sp. nov.,E. limnophilusShimizu,sp. nov.,E. matsumuraiShimizu,sp. nov.,E. pseudopuncticulatusShimizu,sp. nov.,E. sharkeyiShimizu,sp. nov.,E. takakuwaiShimizu,sp. nov., andE. unctusShimizu,sp. nov.), seven are new records from Japan (E. jilinensisTang, 1990,E. laqueatus(Enderlein, 1921),E. multidensChiu, 1954,stat. rev.,E. puncticulatusTang, 1990,E. stenophlepsCushman, 1937,E. vestigator(Smith, 1858), andE. zeugosChiu, 1954,stat. rev.), 32 had already been recorded in Japan; three (E. biharensisTownes, Townes &amp; Gupta, 1961,E. flavicaput(Morley, 1912), andE. merdarius(Gravenhorst, 1829)) have been erroneously recorded from Japan based on misidentifications, and four names that were previously on the Japanese list are deleted through synonymy. The following taxonomic changes are proposed:E. vacuusGauld &amp; Mitchell, 1981,syn. nov.(=E. formosensis(Uchida, 1928));E. multidensstat. rev.;E. striatusCameron, 1899,syn. nov.=E. lineolatus(Roman, 1913),syn. nov.=E. uniformisChiu, 1954,syn. nov.=E. flatusChiu, 1954,syn. nov.=E. gussakovskiiViktorov, 1957,syn. nov.=E. striolatusTownes, Townes &amp; Gupta, 1961,syn. nov.=E. unicornisRao &amp; Nikam, 1969,syn. nov.=E. unicornisRao &amp; Nikam, 1970,syn. nov.(=E. pungens(Smith, 1874));E. iracundusChiu, 1954,syn. nov.(=E. sakaguchii(Matsumura &amp; Uchida, 1926));E. sigmatoidesChiu, 1954,syn. nov.(=E. shikokuensis(Uchida, 1928));E. yamanakai(Uchida, 1930),syn. nov.(=E. shinkanus(Uchida, 1928));E. ranunculusChiu, 1954,syn. nov.(=E. yezoensis(Uchida, 1928)); andE. zeugosstat. rev.=E. henrytownesiChao &amp; Tang, 1991,syn. nov.In addition, the following new regional and country records are also provided:E. flavocephalus(Kirby, 1900),E. puncticulatus, andE. vestigatorfrom the Eastern Palaearctic region,E. laqueatusfrom the Eastern Palaearctic and Oceanic regions, andE. maruyamanus(Uchida, 1928) from the Oriental region;E. abdominalis(Szépligeti, 1906) from Nepal,E. flavocephalusfrom Laos,E. formosensisfrom Laos and Malaysia,E. insinuator(Smith, 1860) from Taiwan,E. maruyamanusfrom India and Philippines,E. nigronotatusCameron, 1903,E. riukiuensis(Matsumura &amp; Uchida, 1926), andE. sakaguchiifrom Indonesia,E. pungensfrom 14 countries (Australia, Bhutan, Brunei, Indonesia, Laos, Malaysia, Nepal, New Caledonia, Papua New Guinea, Philippines, Solomon Islands, Sri Lanka, Tajikistan, and Taiwan), andE. yezoensisfrom South Korea. An identification key to all Japanese species ofEnicospilusis proposed. Although 47 species are recognised in the present study, approximately 55 species could potentially be found in Japan based on ACE and Chao 1 estimators. The latitudinal diversity gradient ofEnicospilusspecies richness is also tested in the Japanese archipelago based on the constructed robust taxonomic framework and extensive samples.Enicospilusspecies richness significantly increases towards the south, contrary to the ‘anomalous’ pattern of some other ichneumonid subfamilies.