甲氰混剂对3种农业害虫的毒力及其增效机理研究

研究了甲基对硫磷、氰戊菊酯及其混剂（１０：１）对３种重要农业害虫粘虫、豆蚜和稻黑尾叶蝉的毒力及其增效机理。生测结果表明：甲基对硫磷与氰戊菊酯混配对粘虫、蚜虫和叶蝉表现出明显的增效作用，其共毒系数分别为１７９．０４、１９１．１２和２１６．４４；生化测定结果表明，在相同浓度下，甲氰混剂对粘虫活体乙酰胆碱酯酶（ＡＣｈＥ）活性的抑制率较单剂高，说明甲氰混剂对ＡｃｈＥ抑制作用增强可能是其重要增效机制之一；根据药剂的毒力值（ＬＣ９０）和价格所进行的应用指数评价结果表明，甲氰混剂的应用指数均高于单剂甲基对硫磷，说明该混剂具有在的应用价值和经济效益。

Toxicity and Synergistic Mechanism of Mixed Insecticide Jiaqing against Three Agricultural Pest Insects

Toxicities and synergistic mechanisms of parathion-methyl, fenvalera te and their binary mixture Jiaqing (10∶1) were studied against oriental armywo r m Mythimna separata Walker, black bean aphid Aphis fabae Scopoli and ric e leafho pper Nephotettix cincticeps(Uhler). Bioassay results revealed that mixed in sect icide Jiaqing exhibited a significant synergism against oriental armyworm, bean aphid and rice leafhopper, and its cotoxicity coefficient (CTC) was 179.04, 191. 12 and 216.44 respectively. According to biochemical studies on in v ivo inh ibition of acetylcholinesterase in oriental armyworm, it appeared that the mixed insecticide Jiaqing had a stronger inhibitory effect on the target enzyme than parathion-me t hyl and fenvalerate alone at the same concentration, indicating that increased inhibition to the acetylcholinesterase in the insect was one of the important sy nergistic factors of mixed parathion-methyl and fenvalerate. Based on LC9 0 value to three insects and price of the insecticides, application index analyses sho wed that the mixed insecticide Jiaqing had a greater application index to three pest insects than parathion-methyl applied alone, suggesting the potential econ o mic benefit and application value of the mixed insecticide Jiaqing in targeted p est management.