Megastylus (Dicolus) impressor Schiødte, 1838 [New SJN: Futahida-ashinaga-hae-himebachi] (Figs. 13A–C, 23F, I, J) Megastylus impressor Schiødte, 1838: 139. Dicolus insectator Förster, 1871: 97. Diagnosis. Inner eye orbit slightly converged ventrally (Fig. 13B). FL I 9.0–11.0 (female) or 12.0 (male) times as long as maximum depth in lateral view. Fore TS I shorter than half length of fore tibia (Fig. 23I). Hind tibia not distinctly narrowed in apical 1/3 (usually slightly narrowed) (Fig. 23J). Propodeum with a distinct transverse depression anterior 0.25–0.28, with both anterior and posterior transverse carinae (Fig. 23F). T I and T II without longitudinal striae. Fore wing length 3.6–5.3 mm. In female: fore TS I 0.33–0.43 length of fore tibia; antennal cleaner of fore TS I not causing conspicuous outcurving of base of TS I. In male: face darkened, except for a narrow yellow area below antennal sockets; pronotum yellow ventrally; mesoscutum darkened; mesopleuron and scutellum reddish brown; hind femur 7.0–8.6 times as long as width in lateral view; T I 2.8–3.3 times as long as maximum width. Material examined. JAPAN: NARO, M, Hokkaido, Kumaishi, Kenichi-gawa, Iwafuchi-zawa, 21– 29. IX. 1995, Y. Ito & T. Ito leg. (MsT); EUM, F, Hokkaido, Bifue, Kusabue-rindo, 17. VIII. – 1. IX. 2012, N. Kuhara leg. (MsT); KPM-NK 89769, F, Niigata Pref., Nagaoka City, Suyoshi Town, Mt. Nokogiri-yama, 21. VII. – 21. VIII. 2014, S. Shimizu & R. Shimizu leg. (MsT); KPM-NK 89769, F, ditto, 21. VIII. – 22. IX. 2014; KPM-NK 89770, F, Toyama Pref., Toyama City, Arimine, Inonedani, 7–14. VII. 2009, M. Watanabe leg. (MsT); KPM-NK 89771, F, ditto, 14–21. VII. 2009; KPM-NK 89772, F, ditto, 21–28. VII. 2009; KPM-NK 89773, F, Toyama Pref., Toyama City, Arimine, Jyurodani, 16–25. VIII. 2009, M. Watanabe leg. (MsT); KPM-NK 89774, F, Toyama Pref., Toyama City, Kamegai, 1–8. IX. 2009, M. Watanabe leg. (MsT); KPM-NK 89775, F, ditto, 15–26. IX. 2009; KPM-NK 89776, F, Toyama Pref., Toga Vil., Kamimomose, 18–25. Aug. 2009, M. Watanabe leg. (MsT); KPM-NK 89777, 89778, 2 F, ditto, 1–8. IX. 2009; KPM-NK 89779, 89780, 2 F, ditto, 15–29. IX. 2009; KPM-NK 89782, M, Tochigi Pref., Nasushiobara City, Shiobara, Oonuma, 6–15. VI. 2008, T. Matsumura leg. (MsT); KPM-NK 80781, M, Kanagawa Pref., Yamakita Town, Minasegawa, 5. V. 2008, S. Yoshizawa leg.; KPM-NK 89783, M, Yamanashi Pref., Koushu City, Sagashio, 6. VIII. 2008, K. Watanabe leg.; KPM-NK 89785, M, Nagano Pref., Tateshina Town, Ashidahakkano, Mt. Tateshina, 26. VIII. 2011, S. Fujie leg.; KPM-NK 89784, M, Shizuoka Pref., Kawanehoncho, Yamainudan, 14. VI. 2008, K. Watanabe leg.; OMNH, F, Ishikawa Pref., Kaga City, Mt. Kariyasu-yama, 28. VI. – 19. VII. 2002, K. Esaki leg. (MsT); OMNH, M, Kyoto Pref., Miyadu City, Kamiseya, Seyakogen, 10. X. 2015, S. Fujie leg.; NIAES, 2 F & 3 M, Fukuoka Pref., Mt. Hiko, 2–3. XI. 1979, H. Takemoto leg. GERMANY: F (det. Rossem), D, BY, Starnberg, Kerschlach, 27. VII. 1927, Haeselb. leg. RUSSIA: ZISP, M (det. Rossem), Kobralovo-Semrino, 29. VI. 1980, D. R. Kasparyan leg. Distribution. Japan (Hokkaido, Honshu, and Kyushu); widely distributed in Holarctic region (Yu et al., 2016). Remarks. This is the first record of this species from Japan.

Published as part of Watanabe, Kyohei, 2023, Taxonomic and Zoogeographic Notes on Japanese Orthocentrinae (Hymenoptera, Ichneumonidae), with Descriptions of Four New Species, pp. 7-44 in Bulletin of the Kanagawa Prefectural Museum (Natural Science) 52 on pages 27-28, DOI: 10.5281/zenodo.11283244