On the ability-inability of Scaphoideus titanus BALL to transmit different grapevine yellows agents*)

In a six-year transmission trial using Scaphoideus titanus BALL the results were negative when the source of inoculum was symptomatic plants from vineyards of the Friuli-Venezia Giulia region. Transmissions were positive when the insects were fed on Perera symptomatic grapevines of the Valdobbiadene area (Veneto region). The data confirm that different types of grapevine yellows (GY) are present in the grapevine areas where we have been working. ELISA and PCR analyses corroborated that transmissions by S. titanus were positive only when the Flavescence doree sensu stricto type of GY is present.