Presence of Scaphoideus titanus on American grapevine in woodlands, and infection with “flavescence dorée ” phytoplasmas

Studies on the occurrence of Scaphoideus titanus Ball (Auchenorrhyncha Cicadellidae) on American grapevine (AGV) in brush-wood areas and in close vineyards, and on its infection with “flavescence dorée ” phytoplasmas (FDp) were conducted in Pied-mont during 2005-2006. S. titanus nymphs were sampled on AGV leaves, whereas adults were captured with yellow sticky traps placed inside vineyards and brushwood areas, and on the borderline. FDP were detected via PCR both on nymphs and adults that fed on AGV. Many S. titanus nymphs were found on AGV in brushwoods. Captures of adults were significantly higher in woodlands than in vineyards, whereas no difference was detected between captures within and on the edge of the vineyard. FDp were detected in nymphs and adults captured on AGV, the infection ranged 27-66%. It may be concluded that woods with AGV can harbour both S. titanus and FDp, but at present they do not seem a serious threat for viticulture if a good pest management is applied