Chironomus (Chironomus) claggi Tokunaga, 1964

(Figs. 10–14)

Chironomus claggi Tokunaga, 1964: 563; Sasa & Suzuki, 1997: 319.

Chironomus simantobeceus Sasa, Suzuki et Sakai, 1998: 49 . syn. n.

Specimens examined: Japan: Tokyo Metropolitan, Bonin Isles, Chichijima Is., ♂,? 14. iv. 1996; [specimen No. 307:04]; Bonin Isles, Chichijima Is., ♂, 14. iv. 1996 [specimen No. 307: 04] and Hahajima Is., ♂, 20. iv. 1996, H. Suzuki [specimen No. 308: 02] ; Kochi Pref., Nakamura, Shimanto River (near mouth), holotype ♂ of Chironomus simantobeceus, 25. v. 1998, M. Sasa [specimen No. 360:01 (NSMT-I-Dip-5222)] .

Chironomus claggi superficially resembles C. flaviplumus Tokunaga and C. yoshimatusi Martin et Sublette, but is well-separable from both these species in having much slender superior volsellae. Although the species also resembles C. cirucumdatus in the shape of the superior volsella, and the uniformly coloured scutal vittae in the former. The morphological features of C. simantobeceus are quite identical with those of C. claggi described by Tokunaga (1964). Furthermore, we observed many pseudospurs on mid and hind tarsomeres in specimen named C. simantobeceus in Sasa, Suzuki and Sakai (1998) .

This is the first record of the species from one of the main Japanese islands, Shikoku.