<i>Alnus glutinosa</i> and <i>Orientus ishidae</i> (Matsumura, 1902) share phytoplasma genotypes linked to the ‘Flavescence dorée’ epidemics

Flavescence dorée (FD) is a grapevine disease caused by associated phytoplasmas (FDp) which are epidemically spread their main vector Scaphoideus titanus. The possible roles of alternative and secondary FDp plant hosts vectors have gained interest in terms better understanding the ecology epidemiology. findings survey conducted surroundings three vineyards southern Swiss Alps aimed at studying epidemiological role Orientus ishidae host Alnus glutinosa reported. This work demonstrates that O. able to complete its biological cycle on A. acquire 16SrV very efficiently with an infection rate 69% for nymphal instars 85% imagoes. A high prevalence map genotype M50 (map type FD1), included S. titanus—grapevine cycle, was found glutinosa. Additionally, M12 FD3), M44 M47 were also sporadically detected. Surprisingly, grapevines tested during this all infected M54 FD2) only, while few titanus caught vineyard canopy free. In conclusion, occurrence common alder stands nearby do not seem play prominent FD epidemics Switzerland. Nevertheless, wild vegetation acts as reservoir inoculum, may locally trigger emergence if populations established inside vineyards.