Xylella fastidiosa Wells is among the most dangerous plant pathogenic bacteria in the world and is responsible for many economically important diseases on agricultural crops and ornamental plants, such as grapevine Pierce’s disease, phony peach disease, citrus variegated chlorosis and olive quick decline syndrome. The meadow spittlebug Philaenus spumarius L. (Hemiptera: Aphrophoridae) has been identified as the main vector of X. fastidiosa in Europe. As this species is widespread throughout the European continent and has not previously posed any threat to agriculture, knowledge about its biology and ecology is scarce, at least for Switzerland. In order to fill this gap and with a proactive approach toward a potential arrival of X. fastidiosa, we are studying the phenology and ecology of P.spumarius in Switzerland. The study of its phenology will identify the developmental periods and the host plants of the different life stages under the Swiss climate, thus informing the development of effective management measures. The ecology is studied across the Southern Alps according to a stratified sampling that considers different combinations of environmental factors (climate, geology and topography, summarized by the Swiss Environmental Domains), habitat (vineyards, olive groves, orchards, meadows, pastures) and management type (intensive vs. extensive). Information about the density of P. spumarius in the different strata is used to model and predict the potential distribution of the vector in the different agroecosystems of the Swiss agricultural landscape and to inform risk assessment for X. fastidiosa.