Evaluation of Attractant Composition, Application Rate, and Trap Type for Potential Mass Trapping of Ips typographus (L.)

This study focused on elucidating the possibilities of improving current trapping methods for Ips typographus (Linnaeus, 1758). Three field experiments were conducted simultaneously in one study area in the German federal state of Saxony. A comparison of six different commercial attractants revealed a significant superiority of Typosan®, especially for adult beetles after hibernation in the phase of their first swarming. It also attracted fewer individuals of Thanasimus spp. than the other highly attractive products Pheroprax® and IT Ecolure Extra®. Increasing the Pheroprax® application rate by using four instead of one dispenser in a single trap increased the total catch of I. typographus only by 15.5%. In contrast, Thanasimus spp. catch increased by 195.5% when four dispensers were used. A test of different trap types showed a species-specific catching capability, with the 12-funnel WitaTrap® being the most effective in catching I. typographus. The quantity of Thanasimus spp. bycatch in multiple-funnel traps demonstrated the necessity of a selective mechanism to minimize impacts on predator populations. Although we were not able to identify new milestones towards mass trapping, this study contributes to necessary improvements of current trapping methods. Especially in future stands with a smaller share of Norway spruce (Picea abies Karsten, 1881) the weakened beetle population in spring could be effectively reduced by properly conducted mass trapping.