Susceptibility and sensibility of grape cultivars to the leafhopper Empoasca vitis
Abstract: The leafhopper Empoasca vitis (Goethe) (Homoptera: Cicadellidae) is a serious pest inEuropean vineyards. The assessment of economic damage caused by E. vitis was associated withno definite results probably because of a different susceptibility and sensibility of grape cultivarsto the pest. Empoasca vitis abundance and symptoms associated with the activity of this pestwere evaluated during three years on 10 grape cultivars grown in collections located in northeasternItaly. Empoasca vitis densities were estimated from May-June to September by samplingleaves every 7-10 days. At vintage time, the percentage of leaf surface with symptoms caused byE. vitis feeding was estimated. Carménère, Sauvignon Blanc and Tocai Friulano showed to bevery susceptible and very sensible, whereas Cabernet Sauvignon, Chardonnay, Verduzzo Friulanoand Pinot Gris showed an opposite behaviour. However, such correspondence was influenced bymeteorological conditions and plant stress factors. These results may be useful for establishingeconomic thresholds and sampling plans for E. vitis in vineyards.