Evaluation of olive cultivar effect on the efficiency of the acquisition and transmission of Xylella fastidiosa by Philaenus spumarius (Hemiptera: Aphrophoridae)

<p>The meadow spittlebug Philaenus spumarius (L.) has been identified as vector of Xylella fastidiosa<br> subsp. pauca strain CoDiRO infecting several host plants in Apulia (Southern Italy), and causing a<br> major bacterial disease on olive trees. Evidences of differential olive cultivar susceptibility to the<br> bacterial infections were obtained from phenotypic characterization and molecular investigations.<br> A higher bacterial population (up to 100 times) was consistently detected in the trees of the most<br> susceptible cultivars (i.e. Ogliarola and Cellina di Nardò, showing severe symptoms), compared to<br> the trees of the cultivar Leccino showing milder symptoms and erratic distribution of the<br> bacterium within the canopy. In order to determine the epidemiological impact of olive trees<br> harboring low bacterial population, transmission experiments were set under semi-field<br> conditions, by caging Xf-free adults of P. spumarius on branches of field-infected trees of the<br> abovementioned cultivars.