Autumnal migration of mature Sympetrum frequens (Selys) in western Kanto Plain, Japan (Anisoptera: Libellulidae)

This is an endemic sp. of Japan and has a migratory nature. Autumnal migration is a return movement of mature individuals from the highlands to the lowlands lor breeding. In the study areas of the Kanto region, they take naturally the course of the foot of Kanto Mountain – Sayama Hills or Kawagoe in the Kanto Plain. This paper treats migration, and other related behaviours in the Kawagoe area.