森戸川（神奈川県三浦半島）におけるホタルトビケラの生活史，特に幼虫の陸上夏眠とよう化および陸上産卵について

Abstract

The life history of the caddisfly, Nothopsyche ruficollis (ULMER), was studied in a small stream on the Miura Peninsula of Kanagawa Prefecture, Japan, from October 1984 to September 1986. The species had a univoltine life cycle. Adults were present from late autumn to early winter and oviposited their egg-mass on the bank. The hatching time of eggs varied greatly, even within an egg-mass, and newly-hatched larvae remained within the gelation until early spring. They may get into the water with rain. There were five larval instars. Larval development occurred during the aquatic stages of the life cycle, from the first to the early fifth instars, present from early spring to early summer. Final instar larvae began to move on land in the early summer and aestivated from early summer to autumn and pupated in the late autumn. The wintering within the gelatinous egg-mass and summer aestivation observed in this species seems to be advantageous to avoid the unstable stream conditions of drought or flooding prevalence in summer and drought or freeze in winter. Although the main larval food was diatoms, vascular plant and animal materials were also found to be utilized as food by aquatic stages. No feeding was evident in terrestrial larvae.