DISPERSAL OF TRYPODENDRON-LINEATUM (OLIVIER) WITHIN A VALLEY SETTING

A mark-recapture study examined Trypodendron lineatum (Olivier) spring flight dispersal in a coastal forested valley in British Columbia. Pheromone-baited traps were placed throughout the valley in five separate experiments. Recapture patterns of marked beetles were related to weather, topography, vegetative cover, and source of attractants. Wind direction within the forest setting, 350 m from the closest open site, was quite variable with a beetle recapture pattern that was non-directional. At a forest setting less than 50 m from an open site and road, diurnal up-valley winds resulted in an upwind beetle recapture pattern at 25 m from the release site. Beetles were recaptured at distances as far as 1.9 km downwind and 1 km upwind from the release site. Most beetles were recaptured within 2 h of release at distances up to 50 m. In traps at distances of 350–700 m, similar numbers of beetles were recaptured on the day of release as were recaptured during the following week. At distances greater than 1 km, almost all beetles took longer than 1 day to be recaptured. © 1990, Entomological Society of Canada. All rights reserved.