Investigations of the mechanism of the transmission of plant viruses by insect vectors III. The insect’s saliva

For the type of virus transmission characteristic of leaf hopper vectors, there is convincing evidence that the virus passes through the insect's body. The manner in which it emerges from the insect and comes to be inoculated into a plant is much less certainly known. It has generally been assumed that the saliva is the vehicle of the inoculation. For this assumption there is even now little direct evidence. I now describe observations on the excretion of saliva by a leafhopper and attempts to demonstrate experimentally in this saliva the virus of which this insect is a specific vector.