Transmission of beet mosaic virus by the green peach aphid starved before infection feeding under different conditions of air humidity

Abstract

Aphids (Myzodes persicae Sulz.) were subjected to infection feeding after starvation for two hours, in varying air humidities. Infection feeding lasted for five minutes. The aphids which were starved under conditions of 0%, 34% and 56% air humidities transmitted the virus to a greater extent than those kept at humidities of 80% and 100%. (At the relative humidity of 0% there was a slight decrease of infectivity, probably due to reduced activity of the aphids). The phenomenon may be explained by the fact than when denied food in a dry atmosphere the aphids lose more water than in a humid atmosphere and hence their rate of feeding when on the source of infection is more rapid, which tends to increase the number of infected individuals. This finding is regarded as having a practical significance.