Grapevine red blotch virus

Grapevine red blotch disease (GRBD), also known simply as red blotch, is a viral disease of grapevine. The disease is caused by a single-stranded circular DNA virus, the species Grapevine red blotch virus, also known as Grapevine red blotch-associated virus, GRBaV. First identified in California, the disease affects grapevines of all varieties and is internationally present. Symptoms typically include red blotches on the leaves of red varieties and in pale green or pale yellow blotches on white varieties. It significantly reduces the value of juice collected from the berries of affected vines, costing vineyard owners as much as $65,000 per acre. The discovery of red blotch and GRBaV is jointly credited to Mysore Sudarshana, a USDA-ARS virologist stationed at UC Davis, and Keith Perry and Marc Fuchs, virologists from Cornell. The three-cornered alfalfa treehopper (Spissistilus festinus) was confirmed as a vector for the disease in 2016, but there are currently no advised treatments for red blotch other than removing and replacing affected vines.

from Wikipedia