Effect of Dosage on Length of Incubation Period of Aster-Yellows Virus in its Vector

Abstract

Summary

Juices from viruliferous Macrosteles divisus Uhler were diluted to 10⁻¹ and 10⁻³ with saline and 1/8000 cc per insect was injected into non-viruliferous leafhoppers. The infectivity tests of injected vectors under controlled environmental conditions showed that with a dilution of 10⁻¹ the shortest incubation periods were from 11 to 15 days. With a dilution of 10⁻³ the minimal incubation periods were from 24 to 38 days. The results can be interpreted on the basis of the fact that multiplication of a small amount of virus would take a longer time to render the insects infective than multiplication of a greater amount of the aster-yellows virus.