Dictyophara europaea an alternative host of Flavescence dorée in Switzerland?

Abstract: Dictyophara europaea has been recently considered as an alternative host of Flavescence dorée, an important grapevine phytoplasma. Unlike Scaphoideus titanus, known so far as the unique vector of Flavescence dorée, its distribution and abundance in Switzerland, as well as its contamination level are unknown. A survey conducted in western and southern Switzerland in 2011 and 2012 using sweep nets, yellow sticky traps and a D-vac vacuum insect collector showed that D. europaea is widespread and common in xerothermic as well as dry ruderal sites close to viticultural areas. However, no insect could be captured inside of vineyards. Moreover, PCR analyses confirmed that none of the 248 individuals tested was harbouring Flavescence dorée isolates. Thus, it is concluded that D. europaea is not a major vector of Flavescence dorée in Swiss vineyards and does not, therefore, represent a major threat to Swiss grapevine production.