Abstract
Seasonal changes and spatial patterns of adult populations of the sugi bark borer, Semanotus japonicus LACORDAIRE, which attacks the trunks of Japanese cedar and cypress were dertermined using a simple banding technique developed by the author. Adults emerged from the trees from March 20 to April 15. Population size based on a mark-release-recapture method was estimated. The spatial distribution patterns of collected adults per tree and daily occurrence of emergence holes were both contagious. This contagious pattern results from lack of dispersal of adults throughout the stands; very little movement of the adults from tree to tree was observed.