Vector Transmission of <I>Xylella fastidiosa</I>: Applying Fundamental Knowledge to Generate Disease Management Strategies

TLDR

Xylella fastidiosa is a xylem‑limited bacterium spread by xylem‑sap feeding insects, infecting a wide range of crops and ornamental plants; its transmission lacks a latent period, is not transstadial or transovarial, persists in adult vectors, and is influenced by bacterial load, insect host range, season, climate, and vector ecology, as illustrated by the rise of Pierce’s disease following the introduction of Homalodisca coagulata. The study proposes that disease control strategies must integrate fundamental knowledge of X. fastidiosa transmission biology, vector ecology, and related interactions.

Abstract

Xylella fastidiosa is a xylem-limited bacterium transmitted to plants by xylem sap-feeding insects. This pathogen has a wide host range, causing disease in crops such as grape, citrus, almond, and coffee; ornamental plants; and trees. Sharpshooter leafhoppers are the major vectors of X. fastidiosa to crops of economic importance. Transmission characteristics include the lack of a latent period, no transstadial or transovarial transmission, persistence in adults, and multiplication in the foregut of vectors. Various factors influence vector transmission of X. fastidiosa, including the distribution and density of bacterial populations in host plants, insect host range and plant preference, season of inoculation, and climatic conditions. The ecology of vectors can affect epidemics, as demonstrated by the large increase in Pierce’s disease of grapevine incidence in California after the introduction of Homalodisca coagulata (Say). Disease control strategies should incorporate basic knowledge of transmission biology, vector ecology, and other interactions involved in X. fastidiosa diseases. We discuss basic aspects of X. fastidiosa transmission by vectors, the ecology of insects in relation to transmission and disease spread, and how basic research can be applied to the development of management strategies for a X. fastidiosa disease.