Success of mating disruption against the European grapevine moth, Lobesia botrana (Den. & Schiff): a whole farm case-study in the Douro Wine Region

Abstract: The European grapevine moth, Lobesia botrana (Den & Schiff.) is the most important pest in the Douro Wine Region (Portugal) and has typically three generations per year, of which the third is the most damaging to grapes. The damage is highly variable amongst years, ranging from 0 to 90% of infested clusters at harvest. The use of mating disruption (MD), an environmentally friendly method to control this pest, is widely recommended in IPM strategies. However, some major constraints to its implementation have been identified in our region: high biotic potential of the moth; high summer temperatures; the steep terrain in many vineyards. Most importantly, the size of the treated area is an important factor for success of the method, which works best in large and contiguous areas. However, the landscape of the Douro Region is very fragmented. The majority of the vineyards are small, often bounded by other crops such as olive groves, and by unmanaged natural or abandoned crop habitats, where alternative plant hosts of L. botrana (e.g. Daphne gnidium L.) are common. Our objective was to investigate the effectiveness of MD against L. botrana within a series of contiguous habitats managed within the“Quinta de São Luíz”, as a case-study. It also served as a demonstration project and to highlight the importance of applying MD on an area-wide scale. The technique was first applied within the farm in 2001 on 4 ha, and expanded to the present 90 ha. MD was shown to be most effective for control of L. botrana after consecutive seasons of application, when large areas were treated, and in years of low pest population density.