Larval habitat preference of Nothopsyche yamagataensis (Trichoptera, Limnephilidae) in Saitama Prefecture, Honshu, Japan

Abstract

Larvae of Nothopsyche yamagataensis were studied in the mountain to middle stream of Arakawa river system in Saitama prefecture. It is a common species in mountain area at central Honshu and, the larvae are usually found abundantly in the pools of streams during late autumn and early summer. In this paper, we report additional records of this species from Saitama prefecture, and the characteristics of their habitat in the prefecture were as follows: (1) the segment is colluvial valley, (2) the reach type is step-pool, (3) the channel morphology is “Aa” type, (4) the larvae were mainly collected in the edge of eddy or plunge pools with the plentiful fallen leaves. On the other hand, another species named Nothopsyche sp. NA closely related to N. yamagataensis was collected from roots of riparian plants (ex. Phragmites spp.) exposing to the flow of river at the lateral pools of middle stream.