2001 Volume 62 Issue 1 Pages 23-39
The life history of a case-bearing caddisfly, Nothopsyche babai Kobayashi was studied in small spring streams of the Omono-gawa Fan, Rokugo-machi, Akita, Tohoku District, Japan, during 1991-1997. This species has a univoltine life cycle with a late-autumn adult period. The first instar larvae appeared from early winter to early spring. Larvae grew rapidly during spring and summer. However, there was a remarkable variation in individual growth. Full grown final instar larvae began the diapause from summer in moss-mat or roots of riparian vegetation just under the water surface. Although the larvae did not move to a terrestrial habitat themselves like other Nothopsyche species of the ruficollis group, most diapause sites became terrestrial at the low-water season in autumn. Annual production for the one population inhabiting a fallen-leaved bottom was 3.82 g m-2 year-1, and for the other population inhabiting a stony bottom it was 10.42 g m-2 year-1. The larvae mainly fed on algae and leaf litter, and animal material was also eaten if available. The variation in larval growth may be caused by differences in the quality and quantity of available food between the two sites.
