Drosophila suzukii and wine grapes: host suitability and other possible impacts

Drosophila suzukii is a global pest attacking various berry crops. D. suzukii lays eggs in damaged as well as in intact wine grape berries of the most soft-skinned varieties. Here we describe the relative host suitability of different wine grape cultivars (international and local), compared to other berry crops. Assessment has been performed both in the field and in the laboratory and results were correlated to the change in the surface penetration force and harvest time of the tested varieties. D. suzukii flies can be found feeding on damaged wine grapes during the harvest period, especially when the skins of berries are impacted by cracking, disease and bird damage. From the results of the present study, it is inconclusive that D. suzukii is a vector of Acetobacteria in wine grapes during the latter portion of the season. Further investigation of the interactions between D. suzukii and Acetobacteria would be necessary to determine whether increased levels of Acetobacteria due to D. suzukii activity levels will impact production cost and quality of high-value wines