Population Growth Of Aphelinus Asychis Parasitizing Sitibion Avenae On Two Wheat Varieties And Functional Response Of Parasitizing Myzus Persicae

In this paper,we investigated the parasitism and oviposition behavior,as well as population growth of Aphelinus asychis on two wheat varieties of AK58 and Xi'nong 979(XN979).We also studied the functional response of A.asychis on cabbage and pepper.Our aim was to select a more appropriate wheat variety as banker plant for banker plant system and provide a theoretical basis for releasing A.asychis to control aphids in the greenhouse.The main results are as follows:1.There was no significant difference in the selection of AK58 and XN979 of A.asychis when it chose its hosts.The length of tibia,parasitism and emergence rate and progeny ratio were no significant difference between two wheat varieties,but the body length was longer when XN979 was the nutrient source.2.Development period of the female was significantly shorter when its host was on XN979 than on AK58,while there was no significant difference when the sex type was male.Survival rate,longevity and adult period of female A.asychis were longer when its host was on AK58 than on XN979,while these three life parameters were just the opposite when the sex type was male.Net reproductive rate of A.asychis was significantly higher when its host was on AK58 than on XN979.The generation time was significantly longer when its host was on AK58 than on XN979,but the intrinsic growth rate(r)of the two wheat varieties were no significant difference.The results showed that both AK58 and XN979 could be used as banker plants for the expansion of A.asychis,but there was a significant difference in male and female.3.The feeding and parasitizing functional responses of A.asychis were fitted to Holling II formula.The instantaneous attacking rate on pepper was 1.0986,higher than on cabbage.The handling time on pepper was 0.0269,shorter than that on cabbage.The searching effects on two host plant decreased with increasing prey density,and pepper showed the larger drop than cabbage under the same prey density.Therefore,we suggest using AK58 and XN979 in the same banker plant system to increase the population of A.asychis.A.asychis can have a certain control effect at different Myzus persicae densities by feeding and parasitizing,and it has a better control effect on pepper compared with that on cabbage.