Constraints to the Application of Mating Disruption against Lobesia Botrana in Douro Wine Region

The mating disruption technique has been applied since 2000 in Douro Wine Region to control the grape berry moth, Lobesia botrana (Den. and Schiff.) (Tortricidae). In most of the trials, ISONET-L (Shin-Etsu) dispensers have been used, in plots whose surface ranged from 3 to 82 ha. The results obtained have shown that moth captures in pheromone-baited traps were significantly reduced in the treated plots compared to the untreated ones. However, the technique did not successfully reduce larval infestation below the tolerance threshold, mainly in the case of the third generation, and insecticides had to be applied. Some constraints have been identified, such as the high biotic potential of the species, the local orography (high steepness), as well as the wind and the high summer temperatures that, in some years, leads to the exhaustion of the pheromone in the dispensers by the end of July, just when the grape berry moth begin the third generation, which is the most damaging. However, the effectiveness of mating disruption in other European countries, along with the need for environmentally safe management strategies for this key pest, is stimulating its use. In this paper, results on the several years of use of mating disruption are critically discussed and weak spots analyzed, as a basis to identify the real possibilities of the technique in Douro Wine Region.