Gone-wild grapevines in forests host phytoplasma genotypes linked to grapevines Flavescence doree epidemics in cultivated vineyards and competent vectors

In Switzerland, FD was identified in 2004 in the southernmost part of Canton Ticino (TI) and then rapidly propagated throughout the entire regional winegrowing area despite the mandatory control measures. The reported widespread distribution of gone-wild grapevines (GWGV) in TI raised the hypothesis of a potential role of GWGV as an FDp reservoir and as a habitat for FDp vectors.

To test this assumption, GWGV and FDp vectors were sampled in 13 plots to attest their infection status and compare the FDp genetic profiles. The primary (Scaphoideus titanus) and best-candidate alternative (Orientus ishidae) vectors were collected throughout the season and were found in moderate to high abundance in all the study area. The infection rate of both GWGV and S. titanus followed the historical gradient of S. titanus arrival and dispersal in TI with a clear geographic distinction between the southern and northern part of TI.