The life cycle of a giant carnivorous caddisfly,

The life cycle of Himalopsyche japonica (Morton) was studied in two high mountain streams at about 1500 m a.s.l. from September 2000 to May 2002 in central Japan. The life cycles in both streams are univoltine. Larval development in upper streams with cooler water is slower than in lower streams with warmer water. The relationships between voltinism or larval size and water temperature are discussed.

Larval mortality with growth and pupation rates of Himalopsyche acharai were compared between standing and flowing water in a laboratory from June to November 2004. In flowing water, 90% of larvae started pupal case building and 81.5% of them developed to pupae by October. In standing water, 92.6% died before pupation. The larvae reared in flowing water grew significantly faster than those in standing water. These results show why Himalopsyche acharai does not inhabit pools and slowly flowing streams.