Optimizing Pest Insect Monitoring in viticulture
Résumé
Pest insect monitoring in French viticulture focuses on leafrollers (Lobesia botrana, Eupoecilia ambiguella) and leafhoppers (Empoasca vitis, Scaphoideus titanus) showing 1 to 4 generations annually. Monitoring of these insects through adult trapping, eggs and larval counts should be optimized for best performance. Large size (up to 12000 ha) monitoring networks have been developed over the last few years. Observation period, density and frequency are based on incomplete expert knowledge on dynamics and mobility. Insect dynamics show strong spatial-temporal structure that seems relatively stable among years. Depending on the species, landscape does influence local abundance. Causal explanations of spatial differences in phenology should relate to meso-climatic factors (temperature, rainfall and drought) through their impacts on key events in the insects life cycle (mating, egg laying). Differences in phenology can also have a huge impact on population dynamics since reproductive success is strongly depending on weather conditions during such key events. Progress is being made to optimize the monitoring network in a socio-economic context as its performance and accuracy depends on its acceptance by the farmers.