采用浸渍法测定烟碱与印楝不同配比对小菜蛾的室内毒力,用孙云沛的共毒系数法评价了2种药剂的联合作用。结果表明:0.3%印楝乳油与70%烟碱乳油2种混配剂对小菜蛾有显著的增效作用,其中混配比为0.125%印楝·14.875%烟碱的增效作用最显著,此时的共毒系数高达264.71。 The indoor toxicity of different doses of nicotine and neem to Plutella xylostella was determined by impregnation method. The combined effect of two agents was evaluated by co-toxicity coefficient method of Sun Yunpei. The results showed that the combination of 0.3% azadirachtin and 70% nicotine EC had synergistic effect on Plutella xylostella, and the synergistic effect was the most significant when the mixture ratio was 0.125%, neem 14.875% Co-toxicity at this time up to 264.71.