Scientific Opinion on pest categorisation of Grapevine Flavescence dorée

The Panel on Plant Health performed a pest categorisation of Grapevine Flavescence dorée, also known as Flavescence dorée phytoplasma (FDP), for the European Union (EU) territory. FDP has not yet been defined as a phytoplasma species of the genus Candidatus Phytoplasma. Routine molecular detection assays are available. FDP is transmitted by grafting and vegetative propagation material as well as by insect vectors. FDP is only reported in Europe. Within Europe it is present in Serbia, in Switzerland and in 10 out of 21 countries of the grapevine producing EU countries. Besides grapevine, FDP is also commonly found in other hosts such as Ailanthus, Alnus and Clematis. FDP is included in the annexes II/A/II and II/B of the Council Directive 2000/29/EC. Grapevine, the main host plant, is included into annexes III, IV and V of the Directive 2000/29/EC. FDP is not expected to be affected by EU ecoclimatic conditions wherever its hosts are present and has the potential to establish largely within the EU territory. The specific leafhopper vector of FDP, Scaphoideus titanus, is an invasive insect that was introduced in Europe. It is only in areas where FDP and Scaphoideus titanus are associated that the direct and indirect impacts are considered to be high: yield reduction, death of grapevine plants, costs for disease and vector management procedures. Additional insect vectors are known, but are not directly associated with FDP epidemics. A major outcome of this pest categorisation has been to emphasise the role of S. titanus. Uncertainty lies mostly in the knowledge on specific FDP strain transmissibility, susceptibility of specific grapevine varieties and distribution in alternate hosts. It is not fully known how far the invasive vector insect S. titanus is still enlarging its distribution within the risk assessment area.