How the Bacterium Spreads
The primary mode of transmission is through xylem-feeding insects, particularly the glassy-winged sharpshooter (Homalodisca vitripennis). These insects acquire the bacterium while feeding on infected plants and deposit it into healthy vines during subsequent feedings. Human activities, such as the movement of infected plant material or nursery stock, can also introduce X. fastidiosa to new regions, exacerbating the spread.