Megastylus (Megastylus) orbitator Schiødte, 1838 [New SJN: Momobuto-ashinaga-hae-himebachi] (Figs. 17A–F) Megastylus orbitator Schiødte, 1838: 139. Mesoleptus maderensis Wollaston, 1858: 21. Mesoleptus albocollaris Cresson, 1868: 100. Myriarthrus rufipleuris Förster, 1871: 103. Megastylus leptoderus Förster, 1871: 105. Megastylus pauxillus Förster, 1871: 105. Megastylus pumilio Förster, 1871: 105. Megastylus rectoligatus Förster, 1871: 105. Orthocentrus albofaciatus Provancher, 1883: 13. Aperileptus pleuralis Ashmead, 1902 in Slosson, 1902b: 321. Megastylus ashmeadi Cushman, 1922: 18. Diagnosis. T I and T II without longitudinal striae (Figs. 17C, F). Hind femur 5.0–5.8 (female) or 5.0– 5.5 (male) times as long as maximum depth in lateral view. Fore wing length 2.5–3.9 mm. Female: clypeus yellow; frons, face, and mesosoma without yellow or yellowish areas (Fig. 17B); OOL: POL = 3: 2 or 3: 3. Male: mesoscutum without light markings at middle; hind tibia not black apically (Fig. 17D); face, frontal orbit, clypeus, palpi, ventral surface of scape and pedicel, fore and mid coxae and trochanters, propleuron, hind corner of pronotum, tegula and wing base ivory (Figs. 17D–F). Material examined. JAPAN: EUM, 2 F, Hokkaido. Sapporo City, Hitsujigaoka, 21–28. V. 2003, K. Konishi leg. (MsT); EUM, 3 F, ditto, 11–18. VI. 2003; 5 F, ditto, 18–25. VI. 2003; EUM, 2 F, ditto, 25. VI. – 2. VII. 2003; EUM, 10 F, ditto, 2–9. VII. 2003; EUM, 2 F, ditto, 9–16. VII. 2003; EUM, F, 16–23. VII. 2003; EUM, F, ditto, 14–21. IX. 2010; EUM, 5 F, ditto, 27–28. VI. 2003 (yellow pan trap in soybean field); NARO, M, Hokkaido, Mt. Daisetsu, Asahidake, 10. VII. 1970, H. Hasegawa leg.; NARO, 3 F, Hokkaido, Ebetsu, Nopporo, 29. VI. – 4. VII. 1992, K. Konishi le. (MsT); NARO, 2 F, Hokkaido, Toyotomi Town, Kabutonuma, 12. VII. 1980, H. Takemoto leg.; NARO, F, Hokkaido, Kumaishi, Kenichi-gawa, Iwafuchi-zawa, 21–29. IX. 1995, Y. Ito & T. Ito leg. (MsT); NARO, F, ditto, 10–20. X. 1995; NARO, F, Hokkaido, Sapporo City, Misumai, Kannon-zawa, 27. VII. – 11. VIII. 1992, N. Kuhara leg. (MsT); NARO, F, Hokkaido, Sapporo City, Jozankei, 20–31. VII. 1989, K. Maeto & M. Sharkey leg. (MsT); NARO, F, Hokkaido, Kamishihoro Town, Nukabira, 30. VI. 1980, H. Takemoto leg.; KPM-NK 89815, F, Hokkaido, Horokanai Town, Uryu, 11–17. VIII. 2012, K. Watanabe et al. leg. (MsT); KPM-NK 89816, M, Hokkaido, Sapporo City, Maruyama, 29. VII. 2009, K. Watanabe leg.; OMNH, F, Miyagi Pref., Minamisanriku Town, Tokura, 6. VIII. – 4. IX. 2016, T. Suzuki leg. (MsT); NARO, F, Tochigi Pref., Yaita, 15–28. VII. 1989, K. Konishi leg. (MsT); KPM-NK 89817, F, Ishikawa Pref., Kaga City, Mt. Kariyasu-yama, 18–30. VII. 2002, K. Esaki leg. (MsT); KPM-NK 89818, F, Toyama Pref., Toyama City, Arimine, Inonedani, 7–14. VII. 2009, M. Watanabe et al. leg. (MsT); KPM-NK 89819, F, Toyama Pref., Toyama City, Kamegai, 4–11. VIII. 2009, M. Watanabe et al. leg. (MsT); KPM-NK 89820, F, ditto, 11–16. VIII. 2009; KPM-NK 89821, F, Toyama Pref., Toyama City, Arimine, Jyurodani, 1–8. IX. 2009, M. Watanabe et al. leg. (MsT); NARO, M, Fukuoka Pref., Mt. Hiko, 2–3. XI. 1979, H. Takemoto leg. GERMANY: ZSM, F (det. Rossem), D, Ostfriesische Inseln, Mellum – Memmert, 11–27. VI. 1986, V. Haeseler leg. UNREADABLE LOCALITY DATA: ZISP, F (det. Rossem), 20. VIII. 1980, Kasparyan leg. Distribution. Japan (Shikotan Is., Hokkaido, Honshu, and Kyushu); widely distributed in Holarctic and Neotropical regions (Yu et al., 2016). Remarks. This is the first record of this species from Hokkaido, Honshu, and Kyushu.

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 32-34, DOI: 10.5281/zenodo.11283244