Effectiveness and side effects of glue-traps to decrease damages caused by Byturus tomentosus in raspberry

Abstract

Damages caused by the larvae of Byturus tomentosus (Coleoptera: Byturidae) are a big problem of European raspberry production. Under integrated pest management conditions in Switzerland, B. tomentosus is controlled by chemical-synthetic insecticides. In organic production, no corresponding insecticides are permitted. White sticky traps (type Rebell^® bianco) are used for monitoring purposes. Can glue-traps also be used for mass-trapping and damage control? In this study, the attractiveness for adult B. tomentosus of one yellow and several white glue-traps was compared by counting the trapped individuals. Trapped beneficial insects like honey bees, Coccinellidae, Syrphidae and Chrysopidae were also counted. The contamination of the traps caused by other non-target arthropods was measured by a computer-assisted method. The white sticky trap type Rebell bianco was the most attractive for B. tomentosus. The attractiveness for the beneficials was relatively low, except when too much glue was applied on the traps, then the attractiveness for honey bees increased significantly. In this study, traps, which were placed in high densities (17 traps per 100 m²), significantly decreased the damages caused by larvae by around 40%. The trapping method does not cause any residuals of pesticides on the fruits or soil. Therefore, the trapping method could be an alternative to control B. tomentosus, especially in organic production.