Abstract: To test the effect of the alcohol content in the pheromone mating disruption (MD)dispenser for Lobesia botrana, a field experiment was set-up in an organic vineyard in theChianti district (Tuscany, Italy). Three kinds of Isonet (Shin-Etsu) dispensers containing differentconcentration of E7,Z9-12OH in the synthetic blend were used (~0.5%, ~2%, ~5%). An untreatedvineyard with similar agronomic characteristics was examined as control plot. No male captureswere obtained in the pheromone traps exposed in MD treated plots. Dissection of tetheredfemales exposed for two consecutive nights during the second flight highlighted the absence ofmating in the pheromone treated plots and a mating rate of about 42% in the control vineyard.Cluster infestation assessment showed in each generation a substantial difference between controland pheromone treated vineyards. As for the third generation, higher alcohol dispensers alloweda significant reduction of the infestation in terms of infested clusters and, overall, injured berriesin comparison with plots covered with lower alcohol dispensers as well.