Hydropsyche orientalis Martynov 1934

Hydropsyche orientalis Martynov 1934, 276–277, fig. 198, male, Russia (Primorye); Tanida 1986, 468–473, fig. 1, male, female, larva, Hokkaido, Honshu, Shikoku, Kyushu, Amami-o-shima, Okinawa-jima; Tanida 1997, 447; Shimura et al. 2014, 43, 55, Amami-o-shima; Kuhara and Ito 2017, 14, 15, Yakushima.

Specimens examined. Amami-o-shima: 14 females, Uken-son, Kogachi-gawa, fall, 19.iii.1999, TI & AO, L; 4 females, Uken-son, Kawaguchi-gawa, 50 m a.s.l., 26.iii.2007, TI, L; 12 females, same locality, 20.x.2014, TI, L; 2 females, Uken-son, 6–8.v.1998, H. Moriya; 1 male, 25 females, Amami-shi, Setouchi, Yakugachi-gawa, middle reach, 5.v.2008, TI, L & S; 14 females, Yamato-son, Materia-gawa, 21.x.2014, TI, L; 1 female, Yamato-son, Yamato-hama, Yamato-gawa, upper reach, 15.v.2014, K. Tojo et al., L; 1 female, Sumiyo-cho, Yakugachi, Yakugachi-gawa, 15.v.2014, K. Tojo et al., L. Okinawa-jima: 2 females, Nago-shi, Genka, 9.x.2008, H. Moriya; 2 males, 26 females, Nago-shi, Genka-gawa, near Hogen-hashi, 22–24.xi.2010, TI, L & P; 16 females, same locality, 8.iv.2011, TI, L & P; 1 male, 28 females, same locality, 17–18.x.2014, TI, P & S; 2 females, Nago-shi, Genkagawa, 40 m a.s.l., 16.iii.2012, TI, L & P; 1 male, 11 females, Kunigami-son, Yona-gawa, Nakafukuji-bashi, 23.xi.2010, TI, P; 2 females, same locality, 18.x.2014, TI, L; 4 females, Kunigami-son, Yona, Sukuna-gawa, 21.iii.1999, TI & AO, L; 2 females, Kunigami-son, Yona, Hiji-gawa, upper reach, 9.iv.2011, TI, L. Kume-jima: 5 males, 8 females, Shirase Dam, 14.iii.1998, M. Maruyama.

Distribution. Japan: Ryukyu (Yakushima, Amami-o-shima, Okinawa-jima, Kume-jima), Hokkaido, Honshu, Shikoku, Kyushu. Continental parts of the Far East Asia.

Remarks. This species is one of the most abundant caddisflies in Far East Asia including Japan and also is common in northern and central Ryukyu.

Japanese name. Urumâ-shima-tobikera.