The European grape moth, Lobesia botrana, in the Douro Demarcated Region: Effect of sub-region, year, generation and grapevine cultivar in the intensity of pest infestation

The European grape moth, Lobesia botrana, is a key pest of vineyards in the Douro Demarcated Region (DDR). The economic importance of this pest, together with the need to reduce the use of synthetic insecticides in the crop has been arousing growing interest in the development of alternative control strategies against the pest. Selection of grapevine cultivars, cultural control measures and mating disruption are some of these strategies. Their appropriate use requires an in-depth knowledge of the insect's behavior in relation to various biological parameters. With the present work, it was intended, through the analysis of data collected between 2000 and 2019, to study the influence of the sub-region, year, generation and the grapevine cultivar on the L. botrana infestation in the DDR. The results showed that infestation: (i) was, in general, lower in the Douro Superior compared to both Baixo Corgo and Cima Corgo; ii) was dependent on the climatic conditions of the year but, tendentially, has been decreasing over the years; iii) in the first generation, generally remained at values below the economic threshold level, while in the remaining generations it was within the limits established for the same (i.e. 1 - 10% attacked clusters); iv) 'Touriga Franca' and 'Malvasia Fina', in the case of red and white grapevine cultivars, respectively, tended to be the most infested cultivars.