关键词: 二斑叶螨, 苦参碱, 蛇床子素, 复配

Abstract: 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.

Key words: Tetranychus urticae, matrine, osthole, compound medicament