Effect Of Pull-Push Strategy On Oviposition Selection Of Plutella Xylostella

A large amount of experiments on pest management was perviously carried out by researchers. The difficulty in controlling pests has increased in recent years due to the increase in pest species and the abuse of pesticides. This paper adopted a pull-push strategy and used Brassica albograbra as the main crop, Brassica chinensis as the trap crop, and Lycopersicon esculentum and Capsicum annuum as repellent crops as a preliminary test of whether this strategy could control Plutella xylostella and to assess the feasibility of the strategies as applied in some trials. The results are as follows.(1) Brassica chinensis was more attractive than Brassica albograbra for oviposition by Plutella xylostella. To a certain extent, Lycopersicon esculentum and Capsicum annuum exhibited repellence of the pest. Both the repellent plants and the trap plant effectively protected the main crop. The effect of the pull-push strategy was more effective than the repellent plant, and the trap plant alone could not protect the main crop.(2) Nearly all eggs that were laid on each of the four species of plants hatched successfully, but the survival of the larvae varied. The larvae on Brassica chinensis and Brassica albograbra had high survival rates, whereas the larvae on Lycopersicon esculentum and Capsicum annuum showed no survival.(3) In various plant arrangement trials, pull-push treatments II, namely the treatment with the trap crop planted around the edges, reduced the mean number of eggs that were laid by Plutella xylostella on Brassica albograbra, which protected the main crop. In comparison with the trap treatment and repellent treatment, the pull-push treatment II significantly enhanced the effect.(4) In biological trials of volatiles, Brassica chinensis volatiles produced a stronger attractiveness for Plutella xylostella. The volatiles from Lycopersicon esculentum and Capsicum annuum affected the location of the pest on Brassica albograbra. This was consistent with the effect of plants on Plutella xylostella. The results show that volatiles are the key factor that influences host-plant oviposition selection by the pest.(5) Various species of plants contain many of the same types of compounds, and their own unique compositions and contents form a specific chemical fingerprint, thereby allowing different types of plants to exert different effects on Plutella xylostella. This is the chemical basis of Brassica chinensis being more attractive than Brassica albograbra and Lycopersicon esculentum being more repellent relative to Capsicum annuum.(6) In the field trial, the quantity of major pests and natural enemies on Brassica albograbra was not significantly different between pull-push treatments and other treatments.