Hydroptila ogasawaraensis Ito 2011

(Figs 9A–9G, 10A–10C)

Hydroptila ogasawaraensis Ito, in Ito et al., 2011, 6–8, male, female, Shigure-yama, a headwater of Yasse-gawa, Chichi-jima, Ogasawara Islands.

Additional records to those reported by Ito et al. 2011. Japan, Ogasawara Islands, Chichi-jima: 5 larvae, beside the type locality, 11.iv.2022, TI & TS, H ; 3 larvae, Nagatani-dam-ue, 14.iv.2019, TI & TS, H (Table 1); 1 male, Tokoyo-gawa, Tokoyo-no-taki, 27.x.2005, K. Satake, L; 3 larvae, same locality, 10.iv.2022, TI & TS, H (Table 1); 3 larvae, Okumura-gawa, 50 m, 10.iv.2022, TI & TS, H (Table 1); 4 larvae, Otaki, 150 m, 11.iv.2022, TI & TS, H (Table 1) .

Final instar larva and case (Figs 10C, 10D). The final instar larva and case are very similar to those of H. ishiura, and could not be discriminated from it.

Remarks. Figures of the type specimens are shown in Figs 9A–9G for comparison with other species in the islands. This is the first hydroptilid caddisfly species described from Ogasawara Islands, showing some similarity with H. chinensis Xue & Yang 1990, found in Far East Asia (Ito et al. 2011). Among the species found in this study, the male of this species is similar to that of H. ishiura sp. nov., but is clearly distinguishable from the latter by the shapes of the dorsal plate and inferior appendages; the dorsal plate is triangular and the inferior appendages are curved ventrad apically in H. ishiura (Figs 6B, 6C); the dorsal plate is subquadrate and the inferior appendages are curved dorsad apically in H. ogasawaraensis (Figs 9B, 9C). The female of this species is also similar to that of H. ishiura sp. nov. and could not be discriminated from it.

Distribution (Fig. 1C). Japan (Ogasawara Islands: Chichi-jima).

Habitat (Figs 10A, 10B). Larvae of this species were found on both hygropetric habitat and stony bottoms in shallow-water flows of small mountain streams.

Japanese name. Ogasawara-hime-tobikera.