Effects of Artificial Migration of Harmonia Axyridis and Chemical Control on the Control Effect of Cotton Aphid and the Population Dynamics of Natural Enemies

【Objective】 To explore the biological control technology of releasing Adonia variegate(Goeze) against cotton field pest-Aphis gossypii and the biological control method of cotton aphid. 【Method】 The control effect of Adonia variegate(Goeze) on cotton aphid outbreak in cotton field was systematically studied by three different treatment measures: release, chemical control and no control. 【Result】 The results showed that the number of aphids in the cotton field decreased significantly compared with that in the CK field, and the number of aphids in the cotton field was close to that in the chemically controlled cotton field after release of Adonia variegate(Goeze) 20 days. There were significant differences in control effect among different treatments. The control effectiveness of biological control cotton field reached the same level as that of chemical cotton field after 30 days of treatment. However, the peak number of Adonia variegate(Goeze) in different growth periods in biological control cotton field was significantly higher than those in the other two cotton fields. 【Conclusion】 The peak duration of Adonia variegate(Goeze) in the biological control cotton field was longer than those in the chemical control cotton field and CK treatment, and its control effect was more stable than that of chemical control cotton field.