Population Density of Aphids on Potato Plants Infected with Leaf Roll Virus

Abstract

In autumn of 1968, population density of aphids on seed born Leaf Roll Virus infected potato plants was examined.
Number of the green peach aphid, Myzus persicae SULZER on diseaed plants was about twice as much as on healthy plants (Fig. 1). It seemed that number of the cotton aphid, Aphis gossypii GLOVER was much more on diseased plants than on healthy ones (Fig. 2). Three varieties of potato, namely Unzen, Tachibana and Chijiwa showed the same result.
The cotton aphid, non-vector of leaf roll virus was controlled entirely by six kinds of insecticides, namely DDT, Lindane, Malathion, PAP, Diazinon and Metasystox-s (Fig. 4). The green peach aphid, vector of this virus, was entirely controlled by only Metasystox-s, but not by the others, particularly, on diseased plants (Fig. 3),
In figures, dotted lines with open circles show the number of insect per healthy plant and solid lines with solid circles show the number of insects per diseased plant.