corky bark, virus-like disease and one of the few which can kill vines. It is one of a complex of diseases known as rugose wood. Symptoms of the disease resemble another one of the virus diseases, leafroll virus, in that, during autumn, leaves turn red or yellow and roll downwards. Vines infected with corky bark retain their leaves after they would naturally have fallen. It can be transmitted to healthy grapevines by the longtailed mealybug Pseudococcus longispinus. There is no control for infected vineyards, and vine removal is the only solution if many vines are infected.