【目的】为明确辣椒碱和茶皂素对棉蚜的防治效果。【方法】室内试验测定辣椒碱和茶皂素对棉蚜的杀虫活性,研究辣椒碱、茶皂素混配的共毒系数;将辣椒碱和茶皂素配制成微乳剂,进行5%辣椒碱.茶皂素微乳剂对棉蚜的田间防效实验。【结果】辣椒碱对棉蚜在处理24和48 h的LD50值分别为343.82和271.54 mg/L;茶皂素对棉蚜在24和48 h的LD50值分别为512.85和321.27 mg/L;二者混配在处理24 h的共毒系数为137.16,表现为增效作用。【结论】5%辣椒碱.茶皂素微乳剂速效性和持效性较好,各处理药后3 d达到最高防效,7 500 g/hm2施药量处理,最高防效为57.40%,略低于吡虫啉450 g/hm2处理时的防效,但是二者没有显著性差异;7 500与3 750 g/hm2的处理间没有显著性差异。 【Objective】 To clarify the control effect of capsaicin and tea saponin on cotton aphid. 【Method】 The insecticidal activity of capsaicin and tea saponin against Aphis gossypii was determined in laboratory experiments. The co-toxicity coefficient of capsaicin and tea saponin was studied. Capsaicin and tea saponin were formulated into microemulsion and 5% Effect of Alkali, Tea Saponin Microemulsion on Cotton Aphid in Field. 【Result】 The results showed that the LD50 of capsaicin to cotton aphid at treatments 24 and 48 h were 343.82 and 271.54 mg / L, respectively. The LD50 values ​​of teasapogenin against cotton aphid at 24 and 48 h were 512.85 and 321.27 mg / L, respectively. The co-toxicity coefficient of mixed with 24 h treatment was 137.16, showing synergistic effect. 【Conclusion】 5% capsaicin and tea saponin microemulsion have good quick-acting and long-lasting effects, the highest control effect is achieved on the 3rd day after treatment, and the highest control effect is 57.40% at the dosage of 7 500 g / Slightly lower than that of imidacloprid 450 g / hm2 treatment, but there was no significant difference between the two treatments; there was no significant difference between 7 500 and 3 750 g / hm2 treatment.