Dichrogaster Doumerc, 1855

Watanabe, Kyohei, 2021, Taxonomic and Zoogeographic Study of the Japanese Phygadeuontinae (Hymenoptera, Ichneumonidae), with Descriptions of 17 New Species, Bulletin of the Kanagawa Prefectural Museum (Natural Science) 50, pp. 55-136 : 94

Genus Dichrogaster Doumerc, 1855

Dichrogaster Doumerc, 1855: 38 . Type: Microgaster perlae Doumerc, 1855 . Monobasic.

Otacustes Förster, 1869: 174 . Type: Otacustes atriceps Ashmead, 1894 (= Otacustes chrysopae Ashmead, 1894 ). Included by Ashmead (1894).

Microtorus Förster, 1869: 178 . Type: Microtorus kichijoi Uchida, 1940 . Designated by Townes (1957).

Xenobrachys Förster, 1869: 179 . Type: Hemiteles longicaudatus Thomson, 1884 . Designated by Perkins (1962).

Brachycephalus Förster, 1869: 179 . Type: Hemiteles aestivalis Gravenhorst, 1829 . Designated by Townes (1944).

Brachycranium Ashmead, 1900b: 368 . New name for Brachycephalus .

Chrysopoctonus Cushman, 1919: 518 . Type: Otacustes atriceps Ashmead, 1894 (= Otacustes chrysopae Ashmead, 1894 ). Original designation.

Four species, Dic. imperialis Yoshida & Konishi, 2008 , Dic. kichijoi ( Uchida, 1940) , Dic. liostylus ( Thomson, 1885) , and Dic. parva Yoshida & Konishi, 2008 , have been recorded from Japan. In this study, I record Dic. nitida Sheng & Sun, 2014 from Japan for the first time and some new distributional data of four previously recorded species below. All species except for Dic. liostylus are relatively rarely collected in the field investigations. Key to species including four previously recorded species has been provided by Yoshida & Konishi (2008). Dichrogaster nitida apparently resembles Dic. liostylus in inclivous 2m-cu, but can be distinguished by the indistinct epomia ( Fig. 63C ) (distinct in Dic. liostylus , Fig. 63B ) and the T II to T IV without dark transverse band ( Fig. 36C ) (usually with dark area(s) in Dic. liostylus , Figs 35A, C ).

Figures

Fig. 63. Acrolyta japonica sp. nov. (A, KPM-NK 54996, holotype), Dichrogaster liostylus (Thomson, 1885) (B, KPM-NK 55074), Dic. nitida Sheng & Sun, 2014 (C, KPM-NK 81908), Bathythrix kuwanae Viereck, 1912 (D, KPM-NK 81718), Retalia japonica Kusigemati, 1985 (E, KPM-NK 81676), Surculus japonicus sp. nov. (F, KPM-NK 81861, holotype), Bentyra ryukyuana sp. nov. (G, KPM-NK 81887, holotype), Hemiteles japonicus sp. nov. (H, KPM-NK 55021, holotype), and H. maculipterus sp. nov. (I, KPM-NK 55025, holotype), females from Japan ― A, median part of collar, dorsal view; B, C, lateral part of pronotum; D–G, mesoscutum and scutellum,dorsal view; H, I, hind tarsus, lateral view.

Fig. 36. Dichrogaster nitida Sheng & Sun, 2014, KPM-NK 81908, female from Japan ―A, lateral habitus; B, head, frontal view; C, head, mesosoma, and metasoma, dorsal view; D, wings.

Fig. 35. Dichrogaster liostylus (Thomson, 1885), KPM-NK 55074, female from Japan ― A, lateral habitus; B, head, frontal view; C, metasoma, dorso-lateral view.