Collaboratrices et collaborateurs

Flavescence dorée (FD) is a detrimental grapevine’s disease, which leads to important economic losses to European viticulture. FD is associated with specific phytoplasmas (FDp), which are acquired and transmitted by the Nearctic leafhopper Scaphoideus titanus. No curative methods are currently available and so far, control measures have been targeted at the vineyard scale, disregarding the role of landscape as a possible source of inoculum and as a suitable habitat for the vector population. In fact, several alternative vectors and host plant species have been identified in the landscape as possible actors in the FD epidemics. In the specific case of Southern Switzerland, the East Palearctic leafhopper Orientus ishidae along with the plant species Alnus glutinosa have been recognized to play an active role in the maintenance of FDp in the landscape, while Corylus avellana was identified as the most suitable host for O. ishidae. Moreover, hazelnut was repeatedly found harboring FDp genotypes. During winter 2021/22, a habitat management experiment was conducted to assess the impact of selective coppicing and removal of hazelnuts for the control of O. ishidae. In the treated sites, the O. ishidae mean populations showed a marked decreasing trend, which went far beyond the seasonal reduction observed in most of the untreated sites, confirming the positive impact of the selective removal of hazelnuts. Habitat management may thus serve as an integrative tool to reduce the population of the alternative vector O. ishidae and the related risk of FDp flow between the forest and the cultivated compartments.