Life history and instar analysis of Stenopsyche griseipennis (Trichoptera)

Abstract

1. The life history of Stenopsyche griseipennis was studied on the basis of the samples taken from the River Yoshino at the stations Ano and Ikadaba, Nara Prefecture and the samples taken from the River Abashiri at the station Abashiri, Hokkaido.
2. Stenopsyche griseipennis has five instars.
3. The accumulated temperature of water temperature required by one generation of Stenopsyche griseipennis is 55 month degrees.
4. The minimum effective temperature is assumed to be 4°C. At about 4°C this larva stops to eat.
5. By the instar analysis it was determined that this species has two generations in a year at the station Ano, three generations in two years at Ikadaba. and only one generation in a year at Abashiri.
6. From the other stand point, that is on the basis of the accumulated temperature the number of generations were estimated.