Rhyacophila motakanta Schmid 1970

Rhyacophila motakanta Schmid 1970 View in CoL

( Figs 9A–9C View FIGURES 8–11 , 13A–13D View FIGURES 12–15 , 16B View FIGURE 16 )

Rhyacophila motakanta Schmid 1970 View in CoL , 206, male; Tani 1977, 198, male; Emoto 1979, 560, 564–566, male, female; Hattori 2005, 422, 431, male, female; Inazu & Nishida 2011, 173, male; Tanaka 2012, 20, 22, male; Nozaki 2016, 70, 311, 313, 429, 449, male.

Diagnosis. The male genitalia of R. motakanta are similar to those of R. orthacantha in having the apically bifid, short apicodorsal lobe, but R. motakanta is easily distinguished from R. orthacantha by bearing the apically truncated anal sclerite without any protuberances apically ( Fig. 9C View FIGURES 8–11 ) (whereas R. orthacantha has the anal sclerites with pair of dark pigmented protuberances apically ( Fig. 11C View FIGURES 8–11 )). The female of R. motakanta is easily distinguished from those of other species by the shape of the vaginal apparatus: The apical part of the posterior process narrows abruptly in lateral and ventral views (arrows in figs 13C, 13D).

Specimens examined. Honshu: Iwate: 3 females, Yakushi-gawa, Taimagura, Etsunagi , Miyako-shi, 10.viii.1994, T . Hattori ( SPMN) . Akita: 2 males, 3 females, Asahi-kawa, Nibetsu , Akita-shi, 20.vi.1997, T . Hattori ( SPMN) . Yamagata: 4 males, Sagae-shi , 18–22.vii.1994, Murakami ( SPMN) ; 3 males, Asahi Mineral Spring, Tateki, Asahi-machi , 2.viii.1983, S. Uchida ( KPM-NKMK74290 ) ; 4 males, 6 females, Higashi-zawa, Hirokawara, Iide-machi , 3.vii.1998, T . Hattori ( SPMN) . Tokyo: 2 males, 9 females, Nippara-gawa, Okutama-machi , 5.vi.1991, T . Kagaya & T . Nozaki (TNo) . Kanagawa: 1 male, Karasawa, Nakatsugawa, Kiyokawa-mura , 14.vi.1989, S. Uchida (TNo) ; 1 male, 2 females, Shiraishizawa, Yamakita-machi , 12–13.v.1983, T . Nozaki (TNo) . Nagano: 2 males, 4 females, Narai-gawa, Shiojiri-shi , 12.vi.2012, T . Ito ( SPMN) ; 1 female, Kamanashi-gawa, Hakushu-cho, Hokuto-shi , 11.vi.1994, T . Hattori ( SPMN) . Gifu: 3 males, Tokuyama-dam, Fujihasi, Ibigawa-cho , 17.vii.1992, F. Hori ( SPMN) . Shizuoka: 5 females, Sugehiki-gawa, Nakaizu-cho, Izu-shi , 14.v.1995, T . Hattori ( SPMN) . Shiga: 2 males, Takatoki-gawa., Kohara, Yogo-cho , Nagahama-shi , 22.v.2010, H. Morita (NKa) ; 5 males, 47 females, same locaality, 27.v.2008, T . Ushijima (NKa) ; 23 males, 1 female, same locality, 28.v.2008, T . Ushijima (NKa) . Hyogo: 1 male, 1 female, Akioka, Kami-cho , 4.vi.2006, K. Inazu (NKa) ; 1 male, 1 female, Kouro, Chikusa-cho, Shisô-shi , 26.vi.2016, K. Inazu (NKa) . Nara: 1 male, Kawaai, Tenkawa-mura , alt. 600 m, 26.v.1974, T . Hattori ( SPMN). Shikoku : Kagawa: 1 female, Kaba-kawa, Shionoe-cho, Takamatsu-shi , 23.v.2000, E. Yamamoto ( SPMN) . Ehime: 2 females, Namakusa-dani, Odamiyama, Oda-cho , 29.v.1999, E. Yamamoto ( SPMN) . Kochi: 2 males (pinned), Kuroson, Okuyanai , Shimanto-shi, 22.v.2011, T . Hattori ( SPMN) ; 11 males, Befu-kyo, Monobe-cho, Kami-shi , 28.v.2004, M. Takai ( SPMN) ; 13 males, Shirai-dani, Teragawa, Ino-cho , 1.vii.2005, M. Takai ( SPMN) ; 1 male, 2 females, same locality, 20.vi.2006, M. Takai ( SPMN) .

Distribution and biology. Rhyacophila motakanta is widely distributed in Honshu, Shikoku and Kyushu ( Fig.16B View FIGURE 16 : Taira et al. 2025). Adults of this species were collected near streams in May to August. Taira (2023) reported that this species had a univoltine life cycle in central Honshu.

Japanese name. Motakanta-nagare-tobikera.