First detection of Flavescence dorée phytoplasma in Phlogotettix cyclops(Hemiptera, Cicadellidae) and considerations on its possible roleas vector in Austrian vineyards

Abstract: The occurrence of Phlogotettix cyclops Mulsant & Rey, 1855 (Hemiptera, Cicadellidae) and its infection with Flavescence dorée phytoplasma (FDp) was surveyed in the wine-growing area in the east of Austria from 2012 to 2017. Individuals of P. cyclops were collected with yellow sticky traps and the beating tray method from selected wild plants nearby to and in cultivated vineyards. Samples of P. cyclops were subsequently analyzed with polymerase chain reaction (PCR) for presence of FDp, the 16Sr subgroup delineation was determined by restriction fragment length polymorphism (RFLP). Results of the survey showed that P. cyclops is widespread in the viticulture regions in the east of Austria and occurs most frequently in Burgenland. P. cyclops was captured in high numbers on Clematis vitalba and Vitis vinifera, less frequently on Ulmus laevis. C. vitalba is described as a new host plant for P. cyclops. 55 out of 156 P. cyclops individuals tested positive for the presence of FDp, all analyzed FD isolates belong to the 16SrV-C subgroup. These data show that naturally FDp infected P. cyclops occurs in Austria. Because this leafhopper species feeds on both, reservoir host plants of FDp and grapevine, it should be considered as potential vector of FDp. Further studies are needed to investigate the ability of P. cyclops to transmit FDp to grapevine and to analyze the phylogenetic relationships of the different FDp isolates. This work describes the first detection of FDp in P. cyclops.