On the ability-inability of Scaphoideus titanus Ball to transmit different grapevine yellow agents.
In a 6-year transmission trial using S. titanus, the results were negative when the source of inoculum was symptomatic plants from vineyards of the Friuli-Venezia Giulia region, Italy. Transmissions were positive when the insects were fed on Perera symptomatic grapes of the Valdobbiadene area, Veneto region. It is concluded that different types of grapevine yellows (GY) are present in areas under study. ELISA and PCR analysis confirmed that transmissions by S. titanus were positive only when flavescence dorée sensu stricto type of GY (MLO) was present.