Feeding Behavior Of Toxoptera Ctricida(Kirkaldy) Impact On Citrus Tristeza Virus Transmission

Citrus tristeza virus is found in worldwide citrus production areas, which is among the most servere virus disease. Toxoptera citricida(Kirkaldy), Aphid gossypii Glover and Toxoptera aurantix(Boyer de Fonscolombe) are the vector of CTV. T. citricida which is the most efficient vector are widely distributed in the world.The transmission of CTV is semi-persistent with T. citricida, so far, very little is known on the mechanisms of the specific CTV-aphid interaction.Plant virus diseases depend on insect vectors,and the transmission of plant viruses by insects is an interaction of insects, viruses and host plants. In some plant–virus–aphid interactions, the virus can affected the behavior of aphids, otherwise, the feeding behavior is influence on the popular speed and development range. As the major research objects in this experiment, the circus aphids are studied by the electrical penetration graph(EPG). We research the CTV transmission affected by the feeding behavior of T. citricida. The results are following:1. The difference feeding behavior on the health and infected plant of T. citricida, A.gossypii, T.aurantix are pathway and phloem phase. Aphid has a more efficient use of phloem sap on the infected plants. The stylet has more opportunities to reach the phloem contact plant virus, thus more opportunities for the acquisition of the CTV.2. T.aurantix have a long time of phloem-sap feeding when T.citricida fed on CVT-infected plants. They prefer feeding on the CTV-infected plants. There is no difference between CTV11-infected and CTV14-infected.3. CTV14 can prevent the feeding behavior, when infected-T.aurantix feeding on infected-plant, but infected-T.aurantix can begin phloem-sap ingestion in early when they feed on infected CTV11 plants and health plant, in order to enhance virus movement to neighbouring healthy plants and therefore, increase the rate of spread. The parameters of phloem phase show that the increasing of ingestion number and time. Infected-aphid has a high food utilization rate when it fed on health plant. Salivation in phloem, at the same time releasethe virus, increases the chances of spreading the virus. Infected CTV14 T.aurantix don’t like feeding on two kinds of infected plants, don’t like feeding on infected CTV14 plant.4. The number and time of probes before infected CTV11 aphids reach the health palnt phloem tissues is less. and there is no difference between CTV11 and CTV14 infected plants. Infected aphid prefer feeding on health plant, as the time from the beginning of that probe to 1st sustained E2 show that T.aurantix don’t like feeding on two kinds of infected plants.