【摘要】 将吡蚜酮、乐果2种杀虫剂混配后用于桑树害虫桑蓟马的防治,旨在减缓害虫对单一杀虫剂的抗性,增强防治效果。在室内28℃±1℃、RH 85%~90%条件下,采用浸叶法测定吡蚜酮、乐果及二者不同配比混配剂对桑蓟马成虫的毒力,用共毒系数法评价2种杀虫剂的混配效果。结果表明:吡蚜酮和乐果对桑蓟马成虫的24 h LC50分别为51.60、209.21 mg/L;吡蚜酮与乐果以1∶4质量比混配后使用对桑蓟马成虫的24 h LC50为93.84 mg/L,共毒系数达138.40,二者混配使用具有显著的增效作用。将此配比的混配剂稀释成不同浓度药液进行田间防治试验,结果表明:质量浓度为312.5 mg/L的吡蚜酮和乐果混配剂对桑蓟马的综合防治效果显著高于125 mg/L吡蚜酮及400 mg/L乐果2种单剂药液的防治效果,且混配剂的速效性和持效期都优于单剂。依据试验结果初步认为,吡蚜酮和乐果混配使用可以增强对桑蓟马的防治效果。更多还原

【Abstract】 To reduce resistance of pests to single insecticides and enhance controlling effect,insecticide mixtures of pymetrozine and dimethoate were used to prevent and control mulberry pest Pseudoden drothrips.The toxicity of pymetrozine,dimethoate and its mixture with different proportions to Pseudoden drothrips was tested by leaf dipping method under indoor environment(28 ℃ ±1 ℃,RH 85% ~90%),and the effect of insecticide mixture was evaluated by cotoxicity coefficient method.The result showed that the 24 h LC50 of pymetrozine and dimethoate to adult Pseudoden drothrips was 51.60 mg /L and 209.21 mg /L respectively,and that of the pymetrozine and dimethoate mixture at mass ratio of 1∶ 4 was 93.84 mg /L with co-toxicity coefficient up to 138.40,indicating that mixed use of the two insecticides had a significantly enhanced effect.Moreover,filed control tests were conducted by using different dilutions of the above mixture.The results showed that the comprehensive control effect of the mixture with mass concentration of 312.5 mg /L was significantly better than that of pymetrozine(125 mg /L) and dimethoate(400 mg /L) used alone.Nevertheless,the quick acting toxicity and effective duration of the mixture was both superior to single insecticides.These results indicate that mixed use of pymetrozine and dimethoate can enhance their control effect to Pseudoden drothrips.更多还原