Abstract: 【Aim】 To determine the biological effectiveness of extracts from Vitex negundo on the development and honeydew production of Aphis gossypii and their active compounds, so as to lay a theoretical basis for its application in agricultural production. 【Methods】 Three extraction methods including organic solvent extraction, supercritical carbon dioxide extraction and steam distillation were used to extract the active components in seeds and leaves from V. negundo. The toxicity of the extracts to apterous adults of A. gossypii was detected by dipping method. Furthermore, total alkaloids were extracted to study its effect on development and honeydew production of A. gossypii by using topical application method. 【Results】 The dichloromethane and methanol extracts from the seeds and the steam distillation extract from the leaves of V. negundo had the highest toxicity to apterous adults of A. gossypii, whose corrected mortalities were 86.98%, 65.01% and 85.27%, respectively, after treatment with 1 200 mg/L essential oil for 24 h. Alkaloids had a definite antifeedant activity towards apterous adults of A. gossypii, with the antifeedant rate of 50% after treatment with 20-40 mg/mL alkaloids for 12 h, and the toxicity of total alkaloids was slightly lower than that of the dichloromethane extracts to apterous adults of A. gossypii. Alkaloids also reduced the survival rate, fecundity and honeydew production of apterous adults of A. gossypii at the concentration of LD₃₀ and A. gossypii adults were all dead at 10 d after treatment, while the survival rate of adults in the control was still as high as 70%. The average total reproduction of each female was reduced by 57.66% as compared with the control, while the honeydew production frequency, honeydew production and weight of each drop of honeydew were reduced by 13.18%, 20.00% and 8.79%, respectively, as compared with the control. 【Conclusion】 The dichloromethane extracts have a higher toxicity to A. gossypii adults, of which alkaloids are the main active components in Vitex negundo and have certain inhibitory effects on the development and honeydew production of A. gossypii.    

Key words:  Vitex negundo, Aphis gossypii, extraction, alkaloid, biological effectiveness, honeydew