EVIDENCE THAT POTATO VIRUS Y IS CARRIED NEAR THE TIP OF THE STYLETS OF THE APHID VECTOR MYZUS PERSICAE (SULZ.)

Abstract

Green peach aphids infective with potato virus Y were made noninfective by exposing the tips of their stylets to ultraviolet radiations in the 2537 Å wave band. Similar results were obtained when the area around the aphid was ventilated during irradiation to carry away the ozone produced by the radiations passing through the air. This irradiation did not appear to harm the aphid even though much of its body was irradiated at the same time. Nor did it affect the infectivity of aphids when their stylets were enclosed by the labium, or when most of the length of the stylets except the tips was exposed to the radiations. Irradiation did, however, reduce the ability of aphids immediately thereafter to acquire potato virus Y during a brief feeding puncture, but this was so whether the tips of the stylets were irradiated or not. Furthermore, an hour after being irradiated, aphids acquired the virus during a brief feeding puncture as readily as did unirradiated controls. It is concluded that irradiation of the tips of the stylets of M. persicae inactivated potato virus Y that otherwise would have been transmitted to the test plants. Only virus near the tips of the stylets appeared to be transmitted even after more than the tips had been inserted into infected tobacco plants.