Spittlebug vectors of Xylella fastidiosa in Apulia

Background Philaenus spumarius (Ps) is the main vector of Xylella fastidiosa (Xf) to olive trees in Italy. Very few information was available about the biology of this insect until 2013, when Xf was found in Apulia. Since then, several studies have been conducted on Ps that have allowed a better understanding of the relationships between this species, the Apulian agrosystem and Xf. Among these lines of research some of the most important are the following: a) phenology, seasonal abundance and stage-structure of Ps; b) dispersal of Ps in agrosystem and c) dynamics of the transmission of Xf. Materials and Methods: Phenology, seasonal abundance and stage-structure of Ps.Field surveys were conducted during the 2016-2018 period in four olive orchards in the Apulia and Liguria regions in Italy. The nymphal population in the herbaceous cover was estimated using quadrat samplings. Adults were collected through sweep nets on three different vegetational components. Dispersal of Ps in agrosystem. In this study, we have examined the dispersal of Ps adults in an olive grove in Apulia and a meadow in Piedmont. Insects were marked with albumin and released during seven independent trials over 2 yr. The recapture data were pooled separately for each agroecosystem and used to estimate the dispersal kernels of Ps. Dynamics of the transmission of Xf. Factors that influence Xf transmission by Ps to olive are still largely unknown. We have performed two sets of experiments to study the transmission biology of Xf by Ps to understand the kinetics of the bacterial persistence, transmission efficiency and the spread rate of Xf among olive trees in summer and autumn. Results: The knowledge obtained from these studies allowed to assess the risk of spread of the bacterium in the territory and to be able to implement more efficient and effective measures to reduce the population of Ps and the spread of Xf in the field.