Insecticide drift pattern and effect on Kampimodromus aberrans (Oudemans) in an Italian vineyard

When a pesticide is applied in a vineyard, a fraction of the sprays can drift from the target and affect the abundance of beneficial arthropods. A field experiment was conducted in North-Eastern Italy in order to evaluate the spatial pattern of pesticide drift in a vineyard-hedgerow system, and its effect on the predatory mite Kampimodromus aberrans. Three scenarios of decreasing potential drift were compared with or without hedgerows: a worst case scenario where the nozzles facing the hedgerows or the adjacent field were not closed, a good agricultural practice scenario where the nozzles were closed and a no-treatment scenario. In the worst case, without hedgerows, 12% of the applied rate drifted for 6-7 m and affected K. aberrans abundance in the adjacent crop. The presence of a hedgerow reduced the drift by about 80%. The hedgerow was also effective when good agronomic practice was followed, and the effect of drift on K. aberrans was not significant. Because of lateral drift, fall-out drift was detected at very low concentration even in an untreated vineyard, posing a risk to surface water and bystanders. This suggests that nvironmental regulatory schemes taking edgerows into account should be supported and implemented on a multi-farm or regional scale.