However, PCR tests have recently been developed that are capable of not only detecting a wide range of grapevine virus diseases, but the bacteria that causes crown gall disease, Agrobacterium vitis, and Pierce's Disease, Xylella fastidiosa, as well as the phytoplasms which cause flavescence
doree or Grapevine Yellows.
The first described occurrence of GY was in France in the '40s, and that disease was termed flavescence doree (Caudwell, 1981).
As such, the phytoplasmas detected in Virginia were shown to be genetically different from the phytoplasma that causes flavescence doree (16SrV, elm yellows group), and also different from phytoplasmas that cause the GY disease known as bois noir in Europe (16SrXII).
The leafhopper vector of flavescence doree, Scaphoideus titanus, is native to eastern North America, and may be involved in phytoplasma transmission there.
While there is some evidence that flavescence doree can be spread via infected propagation material (e.
Caudwell (1983) proposed that the flavescence doree phytoplasma was imported into France, along with its only known vector, Scaphodius titanus from North America.
Occurrence of flavescence doree-like symptoms on 'White Riesling' grapevines in New York, USA.