Grapevine leafroll associated viruses (GLRaV’s) occur in all major grape producing regions of the world, causing delayed ripening and reductions in yield and fruit quality. These negative impacts on grapevines are of particular concern to the BC wine and grape industry due to the short growing season and an emphasis on production of high quality fruit. This study will provide critical information about the occurrence of the various GLRaVs and their insect vectors in BC vineyards and determine their effects on vine growth and fruit and wine quality under cool temperate conditions.