Field response of non-target beetles to Ips sexdentatus aggregation pheromone and pine volatiles

Although mass trapping cannot be a definitive control measure, it is one of the few ones available to contain the destruction of millions of cubic metres of conifer forests perpetrated every year worldwide by bark beetles. However, using bark beetle aggregation pheromones during both monitoring and control programs may negatively affect other saproxylic insects. The aim of this study was to describe the response of both Ips sexdentatusand its saproxylic beetle associates, especially predators, to traps baited with a commercial blend ofI. sexdentatus aggregation pheromone. Furthermore, the usefulness of adding pine volatiles, such as ()-a-pinene and ethanol, to the pheromone was discussed. The commercial blend proved to be attractive toI. sexdentatusadults, both when used alone and together with pine volatiles. Pheromone attractiveness, however, was lessened by the addition of the volatiles. The pheromone blend proved to be attractive toThanasimus formicarius, as well as to other predator species. Overall, although during our study, traps baited only with ()-a-pinene and ethanol attracted some predator specimens,I. sexdentatuspheromone traps were more attractive. Our study confirms that calendar differences in flight activity between the bark beetle and its predators are substantial; therefore, they should be taken into account when planning control measures. According to our data, the commercial blend ofI. sexdentatuspheromone seems to be the most effective, among the baits used, in catching I. sexdentatusadults, while reducing the impact onT. formicarius.