Spread of phytoplasmas by insect vectors

Vector-host plant interactions play an important role in limiting or expanding the spread of phytoplasmas. Polyphagous vectors have the potential to inoculate a wider range of plant species, depending on the resistance to infection of each host plant The spread of phytoplasmas by their insect vectors is on one hand determined by a strict vector definition based on specific acquisition and transmission characteristics which a priori exclude certain insect species as competent vectors. But once a species fulfils the basic vector criteria multiple biotic and abiotic factors may influence the vector-host plant interactions and hence the epidemiology of a disease.