Determination of the limiting amount of tobacco mosaic virus attaching to ion exchange resin and the dissociation constant of their complex

Abstract

The only aphids used were wingless adults of Myzus persicae (Sulz.). So that either pair of their stylets could be treated separately, the two outer stylets (mandibles) were teased away from the interlocked middle pair (maxillae). When this was done to aphids carrying alfalfa mosaic virus, cucumber mosaic virus, or potato virus Y, more than half of them ceased to be viruliferous. The remainder could nearly always be rendered nonviruliferous simply by dipping the end of their maxillae into water a few times. In further trials made only with cucumber mosaic virus, ultraviolet irradiation of the end of the maxillae also rendered nearly every aphid nonviruliferous, whereas irradiating the end of each mandible did not. None of the above treatments impeded transmission by adversely affecting the behaviour of aphids. With viruliferous aphids, therefore, dipping the maxillae into water must remove the transmissible virus from them, and irradiating them must inactivate it. Therefore, the maxillary stylets carry transmissible virus. Whether the mandibles do or not could not be decided because of an experimental technicality. But there was no reason to suspect them as important virus carriers.