Epidemiological research was carried out in two vineyards affected by "Bois noir" (BN). Auchenorrhyncha potential vectors of BN, were monitored periodically between May to November 2004 in a vineyard and between May to June 2005 in the other. Auchenorrhyncha samples were tested to assess phytoplasmas presence using PCR and RFLP. Euscelis ttneolatus was positive to 16SrI-C ("Clover phyllody" reference strain) in 2004 while, in 2005, at the preimaginal age, at the 16SrXII -A ("Stolbur" reference strain) phytoplasmas. Exitianus taeniaticeps acquired 16SrI-B ("Maryland aster yellow" reference strain), 16SrV-A ("Elm yellow" reference strain) and 16SrX-C ("Pear decline" reference strain) phytoplasmas in 2004. Resulted news host of phytoplasmas: Psammotettix alienus was positive to 16SrI-B, 16SrV-A, 16SrX- A phytoplasmas ("Apple proliferation" reference strain) in 2004 and to 16SrXII -A in 2005. K lineolatus and P. alienus for 16SrXII -A E. taeniaticeps for 16SrV-A 16SrX-C and P. alienus for 16SrV-A and 16SrX-A Researches on the effective epidemiological role of K lineolatus and P. alienus in BN are in progress.