Adult populations of the sugi bark borer,Semanotus japonicus Lacordaire (Coleoptera: Cerambycidae), in Japanese cedar stands: Population parameters, dispersal, and spatial distribution

Summary Adult populations of the sugi bark borer,Semanotus japonicus Lacordaire, which attacks the trunks of Japanese cedar and cypress, were studied in two cedar stands in 1981 and 1984, using a band-trapping method developed by the author. Adults began to emerge and fly earlier in 1981 than in 1984 because of the higher temperature after hibernation in 1981. Population size wasestimated by a markrelease-recapture method. The daily survival rate ranged from 0.86 to 0.92 and the mean longevity from 7.0 to 11.9 days. Females were fewer than males throughout the season, especially early in the flight period, because males consistently emerged earlier. The mean distances traversed among the cedar trees were 9.2 m for males and 16.3 m for females; maximum dispersal was 79.5 m for males, 149.5 m for females. There are two different patterns in their dispersal movement: the small-scale movement which consists of walking at cool temperatures and large-scale flight at warm temperatures. Adults of this species are somewhat sluggish and between-tree movement is infrequent. This lack of movement resulted in a contagious distribution pattern of adults.