Does bark beetle Ips typographus (L.) die after flying away from the poisoned trap tree?

Abstract

Ips typographus (L.) is the most significant insect pest in the European spruce forests. Methods of control and monitoring are in the period of Ips typographus (L.) outbreaks supplemented with suppressive procedures applying insecticides. The aim of our study was to determine the necessary length of Ips typographus (L.) imagoes movement across the treated surface, resulting in their death also in the case of their flying away from the trap tree. Insecticides Forester (active substance cypermethrin) and Dinastia (active substance deltamethrin) were tested in laboratory conditions. Exposure times the beetles moved on the intoxicated bark were 30–300 s. Then the beetles were placed in Petri dishes and their survival rate up to twenty-four hours was established. Experiment duration was 8 weeks from spraying with repeated week control tests. High efficiency of tested pyrethroids ensuring the death of also flying away imagoes within six hours after contamination was established at three weeks. The rate of their survival was increasing from Week 4 independently on the exposure times (deltamethrin). In cypermethrin, the survival rate of imagoes was high and dependent on the exposure times. The efficiency of deltamethrin was higher than that of cypermethrin. During the outbreaks, the pheromone-baited poisoned trap trees causing the death also to flying away imagoes of Ips typographus (L.) have to be sprayed with the above-mentioned pyrethroids in a monthly interval at the time of swarming culmination. The efficiency of both insecticides decreased more rapidly on the upper unprotected side of the trap tree.