Physical barriers against Drosophila suzukii in viticulture

Abstract: Drosophila suzukii is a major pest in fruit production, which is controlled in stone fruit orchards and soft fruits by exclusion nets and the application of stone powders. Here we test if these control strategies could also be applied in vineyards. Kaolin clay applied at the very beginning of oviposition reduced the number of deposited eggs by 58% at harvest and its usage did not affect wine quality and predatory mites. Insect-proof nets as well as fine-meshed nets against wasps and birds reduced substantially the activity of the fly in the grape zone (83% and 46%, respectively), decreased oviposition (93% and 70%, respectively) and lowered rot diseases (sour rot and Botrytis cinerea) at harvest. Anti-hail nets provided, however, an insufficient protection. Thus, kaolin and fine meshed nets are interesting alternatives for controlling D. suzukii in vineyards.