Use of antagonistic yeasts for multi-purpose grape and wine protection: attraction for Drosophila suzukii in pre-harvest and bioprotection during red winemaking

Drosophila suzukii poses a significant threat to grape and wine production by directly damaging berries and promoting fungal infections. Several environmental and regulatory issues, together with the emergence of resistance phenomena, limit the feasibility of an extensive use of synthetic insecticides, making the search for sustainable alternatives crucial. Among these, attract-and-kill strategies using yeasts as baiting agents have been proposed. This study evaluated the attraction potential for D. suzukii of Starmerella bacillaris, previously reported to have antifungal activity against Botrytis cinerea and potential as a non-Saccharomyces starter in winemaking. The yeast attractivity was firstly compared with strains with recognized oenological and/or biocontrol activities, showing to be largely preferred, and then was tested for attraction after being sprayed on grapes, confirming the attractant effect on D. suzukii females. In addition, the oenological compatibility of the yeast was assessed by evaluating its effect on grape must fermentation and wine quality. Starm. bacillaris reduced the growth of the undesired yeast Hanseniaspora uvarum and enhanced wine color stability through improved anthocyanin preservation. Overall, the results highlight the potential for using Starm. bacillaris to develop an attract-and-kill protocol for managing D. suzukii during the preharvest period, while limiting the concurrent appearance of rotting agents and reducing the risk of compromising wine quality after harvest, paving the way for the design of D. suzukii control strategies that respect winemaking process.