苦参碱和蛇床子素复配对草莓二斑叶螨杀螨活性的影响

研发一种高效、安全、环保的植物源杀螨剂配方,本文选取两种对二斑叶螨具有较好杀螨活性的植物源药剂——苦参碱和蛇床子素。通过毒力比和孙云沛法筛选最佳的复配比例,并进行盆栽试验。结果表明:苦参碱和蛇床子素两种单剂的LC₅₀分别为1770.504 mg/L和1898.148 mg/L。将苦参碱和蛇床子素按照有效成分比为1:4.29进行复配,该复配药剂的LC₅₀为1276.656 mg/L,共毒系数为146.6(大于100),增效作用最明显。经盆栽验证试验,药后1 d、3 d、5 d、7 d,复配药剂的校正防效均高于10%苦参碱和11.35%蛇床子素单剂,药后7 d差异显著,药剂的持效期延长,对开发苦参碱和蛇床子素复配药剂防治二斑叶螨提供了理论依据。

Acaricidal of Activity of Matrine and Osthole Mixture against Tetranychus urticae Koch on Strawberry

T two botanical acaricides matrine and osthole that have high acaricidal activity against Tetranychus urticae Koch were screened using potted plant experiment through the toxicity ratio and Sun Yunpei's method for the optimal mixture formula of an efficient,safe and environment-friendly botanical acaricides.The results showed that LC₅₀ of matrine and osthole were 1770.504 mg/L and 1898.148 mg/L,respectively.When matrine and osthole were compounded according to the ratio of effective components of 1:4.29,LC₅₀ of the compound was 1276.656 mg/L and the co-toxicity index was 146.6,showing an obvious synergistic effect.The potted plant experiment showed that the control achieved with the compound insecticide was higher than that of either 10% matrine or 11.35% osthole at 1,3,5 and 7 days post treatment.The significant difference in control at the seventh day post treatment proved that the persistency period of the compound insecticide was prolonged.These results will aid the development of matrine and osthole compound insecticide to control T.urticae.