Investigations of the Mechanism of the Transmission of Plant Viruses by Insect Vectors II. The Part Played by Puncture in Transmission.

Abstract

In an earlier paper (Storey 1933) I showed that, after Cicadulina mbila Naude had fed on a source of the maize streak virus, this virus appeared externally to the intestine in the insect’s blood. The next stage, it may be supposed, is the collection of the virus at some centre whence it becomes available for ejection into a plant. It seems hardly possible to doubt that this centre is the salivary gland, and that the saliva is the vehicle whereby the virus is transferred into the plant. Nevertheless, my attempts to demonstrate a virus in the saliva have met with almost uniform failure. The problem of the mechanism of inoculation is thus not simply solved. As one step towards its solution, I now present evidence bearing upon the factors that decide whether an insect succeeds in causing the infection of the plant. In a later paper I shall consider the process of excretion of saliva and attempt to relate the facts so obtained to the conclusions of the present studies.