Bathythrix Förster, 1869

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 : 68-69

Genus Bathythrix Förster, 1869

Ischnurgops Förster, 1869: 175 . Type: Cryptus claviger Taschenberg, 1865 . Designated by Viereck (1914).

Steganops Förster, 1869: 175 . Type: Cryptus claviger Taschenberg, 1865 . Designated by Viereck (1914).

Bathythrix Förster, 1869: 176 . Type: Bathythrix meteori Howard, 1897 . Designated by Viereck (1914).

Panargyrops Förster, 1869: 182 . Type: Cryptus claviger Taschenberg, 1865 . Designated by Viereck (1914).

Gausocentrus Förster, 1869: 198 . Type: Gausocentrus gyrini Ashmead, 1894 (= Hemiteles gyrinophagus Cushman, 1930 ). Designated by Viereck (1914).

Stenoschema Förster, 1869: 220 . Nomen nudum.

Leptocryptus Thomson, 1873: 1884 . Type: Cryptus claviger Taschenberg, 1865 . Designated by Viereck (1914).

Agenora Cameron, 1909: 722 . Type: Agenora hirticeps Cameron, 1909 . Monobasic.

Six species, Ba. claviger ( Taschenberg, 1865) , Ba. kuwanae Viereck, 1912 , Ba. linearis ( Gravenhorst, 1829) , Ba. narangae ( Uchida, 1930) , Ba. prothorax Momoi, 1970 , and Ba. sericea ( Provancher, 1875) , have been recorded from Japan. In this study, I newly record Ba. marginatae Sawoniewicz, 1980 and Ba. thomsoni ( Kerrich, 1942) from Japan and newly synonymized Ba. narangae under Ba. kuwanae below. In addition, I record some distributional data of all Japanese species below. Japanese species including unidentified species can be distinguished by the following key.

Preliminary key to Japanese species of the genus Bathythrix (♀)

(female of Ba. prothorax is unknown)

1. Face strongly narrowed ventrally, eye almost reaching basal part of mandible ( Figs 13B , 62B ). ........................ Ba. marginatae Sawoniewicz, 1980

-. Face not strongly narrowed ventrally, eye not reaching basal part of mandible (e.g., Figs 12B , 62A, C ). ............................................................ 2

2. Anterior tentorial pit exceptionally large, extending from the margin of clypeus and basal part of mandible to lower eye margin, with long dense setae inside ( Figs 15B , 62C ). And nervellus not intercepted. ...................................................................... 3

-. The combination of above character states lacking. ....................................................................... 5

3. Lower part of occipital carina absent near hypostomal carina. ................................................................ Ba. sp. A

-. Lower part of occipital carina complete. ........................................................................ 4

4. T II and T III covered with longitudinal striae ( Fig. 15C ). ...................................... Ba. thomsoni ( Kerrich, 1942)

-. T II and T III covered with punctures, without longitudinal striae. ......................................................... Ba. sp. B

5. Anterior tentorial pit exceptionally large, extending from the margin of clypeus and basal part of mandible to lower eye margin, with long dense setae inside. The margin of the pit invisible. ...................................................... Ba. sp. D

-. Anterior tentorial pit not exceptionally large, without long dense setae inside (e.g., Fig. 62A ). The margin of the pit at least largely visible (e.g., Fig. 62A ). ................................................................. 6

6. T II and T III covered with longitudinal striae. ........................................................ Ba. spp.

-. T II and T III covered with punctures, without longitudinal striae. ................................................................... 7

7. T II and T III largely red, with black spots ( Figs 11A, C ). And hind femur and tibia reddish yellow with conspicuous black apex ( Fig. 11A ). ................................ Ba. kuwanae Viereck, 1912 (= Ba. narangae Uchida, 1930 syn. nov.)

-. The combination of character states lacking. ................................................................. 8

8. Ovipositor sheath shorter than 1.3 times as long as hind tibia. And/or metasomal tergites with large red area(s). ............................................. Ba. spp.

-. Ovipositor sheath longer than 1.5 times as long as hind tibia ( Figs 10A , 12A ). And metasomal tergites entirely black (posterior margin sometimes narrowly tinged with reddish brown) ( Figs 10C , 12C , 16C ). .................................................... 9

9. Hypostomal carina strongly raised behind the base of mandible. Dorsolateral carina of T I absent beyond the spiracle. Hind coxa and femur dark reddish brown to black ( Fig. 12A ). ..................... Ba. linearis ( Gravenhorst, 1829)

-. Hypostomal carina not raised behind the base of mandible. Dorsolateral carina of T I present or absent beyond the spiracle. Coloration of hind coxa and femur various. ................................................................. 10

10. Dorsolateral carina of T I at least present beyond the spiracle. Coxae and hind femur reddish brown ( Fig. 10A ). ......................... Ba. claviger ( Taschenberg, 1865)

-. Dorsolateral carina of T I absent beyond the spiracle. Fore and mid coxa whitish yellow. Hind coxa and hind femur dark reddish brown to black ( Figs 16A, C ). ........................ Ba. sericea ( Provancher, 1875)

Figures

Fig. 13. Bathythrix margaretae Sawoniewicz, 1980, KPM-NK 55017, female from Japan ― A, lateral habitus; B, head, frontal view; C, head, mesosoma, and metasoma, dorsal view.

Fig. 62. Bathythrix kuwanae Viereck, 1912 (A, KPM-NK 81718), Ba. margaretae Sawoniewicz, 1980 (B, KPM-NK 55017), Ba. thomsoni (Kerrich, 1942) (C, KPM-NK 81675), Diaglyptidea conformis (Gmelin, 1790) (D, KPM-NK 81645), Nipponaetes haeussleri (Uchida, 1933) (E, KPM-NK 81832), Acrolyta japonica sp. nov. (F, N, KPM-NK 54996, holotype), Acr. rufocincta (Gravenhorst, 1829) (G, KPM-NK 81732), Surculus japonicus sp. nov. (H, KPM-NK 81861, holotype), Isadelphus nigrus sp. nov. (I, KPM-NK 82003, holotype), Lochetica japonica sp. nov. (J, KPM-NK 81989, holotype), Megacara similis Sheng, 1999 (K, KPM-NK 81837), Gnotus chionops (Gravenhorst, 1829) (L, KPM-NK 82100), Gn. striatus (Uchida, 1930) (M, KPM-NK 82060), and Acr. flavicoxis Sheng & Sun, 2014 (O, KPM-NK 81837), females from Japan ― A–C, head, frontal view; D, E, head, lateral view; F–K, anterior margin of clypeus; L, M, mandible; N, O, basal part of antenna, lateral view.

Fig. 12. Bathythrix linearis (Gravenhorst, 1829), KPM-NK 81695, female from Japan ― A, lateral habitus; B, head, frontal view; C, head, mesosoma, and metasoma, dors0-lateral view; D, wings.

Fig. 15. Bathythrix thomsoni (Kerrich, 1942), KPM-NK 81675, female from Japan ― A, lateral habitus; B, head, frontal view; C, head, mesosoma, and metasoma, dorsal view.

Fig. 11. Bathythrix kuwanae Viereck, 1912, KPM-NK 81718 (B) and 81719 (A, C), females from Japan ― A, lateral habitus; B, head, frontal view; C, head,mesosoma, and metasoma, dorsal view.

Fig. 10. Bathythrix claviger (Taschenberg, 1865), KPM-NK 81876, female from Japan ― A, lateral habitus; B, head, frontal view; C, head, mesosoma, and metasoma, dorsal view.

Fig. 16. Bathythrix sericea (Provancher, 1875), KPM-NK 55019, female from Japan ― A, lateral habitus; B, head, frontal view; C, head, mesosoma, wings, and metasoma, dorsal view.