Recapture of marked spruce bark beetles (<i>Ips</i><i>typographus</i>) in pheromone traps using area-wide mass trapping

Abstract

Mark–release–recapture experiments were performed with Ipstypographus (L.) populations to estimate recapture rates (number recaptured/number released) in pheromone traps. The recapture rate of bark beetles marked during spring emergence during 2 consecutive years was about 8% in trap groups set 100 m from release sites and decreased to about 2% in trap groups set 1200–1600 m away. The rate at which recapture declined with distance was slower than predicted by a model in which the decrease in recapture depends only on the dilution of released beetles. Sixty percent of the variation in recapture rates was explained by the distance between release and recapture points. The relationship between distance and rate of recapture was used to estimate the rate at which regional beetle populations may be captured using area-wide mass trapping.