The Behaviour of Spruce Bark Beetle Ips Typographus (L.) (Coleoptera, Scolytidae) During Flight Time in Mixed Forest Stands

1991

S. 669-675

Unselbständiges Werk

200062040

In the ecosystems of mixed stands of beech and spruce in Southern Bohemia trials were made to investigate the behaviour and orientation of spruce bark beetle (Ips typographus L.) during flight time. Marked imagoes of spruce bark beetle and pheromone traps located in forest stands at distances of 200, 400 and 1000m were investigated. Out of the total number of marked spruce bark beetles only 65,6% individuals were caught in pheromone traps. The highest number of individuals was caught in pheromone traps at a distance of 1000m from the place of release 67,8%; at distances of 400m and 200m the percent of entrapped beetles made 18,8% and 13,4% of the total number of caught marked spruce bark beetles, respektively. The number of entrapped beetles in dependence on exposure: western exposure 45,5%, easter exposure 37,5%, southern exposure 12,9% and northern exposure 4,1% of the total number caught marked spruce bark beetles. During flight time of marked beetles, the highest catch of spruce bark beetles was recorded on the first days after release them fly, on the following days it was decreasing. Four days after release, no marked spruce bark beetles was caught in pheromone traps.