STUDIES ON RUBUS VIRUS DISEASES IN BRITISH COLUMBIA: VII. RASPBERRY VEIN CHLOROSIS
A virus disease occurring in the Lloyd George variety of red raspberry (Rubus idaeus L.) in British Columbia has been identified as raspberry vein chlorosis, a disease previously reported from Scotland. The virus was transmitted to the Lloyd George and Washington varieties of red raspberry, loganberry (R. loganobaccus Bailey), and the Alpine strawberry (Fragaria vesca L.) by the aphid Aphis idaei V.d.G. In each of these hosts, the characteristic symptom was a net-like chlorosis of the tissue bordering the smaller veins of the leaf. The large raspberry aphid, Amphorophora rubi (Kalt.), was not a vector. Experiments using A. idaei showed that most individuals require more than 1 day on the virus source to become viruliferous. The length of time that aphids remained viruliferous depended upon the conditions of the test; viruliferous aphids feeding upon healthy raspberry plants lost the ability to transmit the virus within a day, while those feeding upon strawberry, or held in a Petri dish without food, retained the virus longer than 1 day.