Abstract
The Japanese species of Hydroptila Dalman (Trichoptera, Hydroptilidae) are reviewed, confirming 10 described species, and introducing 2 new species. For clear comparisons and to include new details, males and females of all species, including the 2 new species, H. ogasawaraensis Ito and H. nanseiensis Ito, are redescribed or described anew. Hydroptila itoi Kobayashi is synonymized with H. dampft Ulmer and H. thuna Olah and H. botosaneanui Kumanski are recorded for the Japanese fauna for the first time. Hydroptila usuguronis Matsumura is reassigned to the genus Psychomyia Latreille (Psy-chomyiidae).
NSTL