有机磷与拟除虫菊酯农药联合作用的研究

Study on the joint action of organophosphorus and pyrethroid pesticides

目的 研究有机磷与拟除虫菊酯农药的联合作用。方法 用点滴法测定棉铃虫、用寇氏法测定SD大鼠的辛硫磷 (Pho)与氰戊菊酯 (Fen)、辛硫磷与三氟氯氰菊酯 (Clo)、丙溴磷 (Pro)与高效氯氰菊酯 ( β Cyp)混剂及单剂的LD50 及 95 %可信限 ,按谭福杰法计算混剂对棉铃虫幼虫的共毒系数 (CTC) ,并用预期与实测LD50 对比法和Logistic回归分析法判断混剂对大鼠的联合作用特征。结果 3种组合的混剂对棉铃虫幼虫都有明显的增效作用 ,Pho +Fen、Pro +Clo和Pro + β Cyp的CTC分别为 3 4 0、797和172 ;Pho+Fen复配有协同作用 ,其预期LD50 (E)与实测LD50 (O)的比值———E/O值、CTC和Logistic回归分析的联合作用参数 ( β3)分别为 2 .69、2 85和 0 .0 0 15 ;Pho +Clo复配有相加作用或协同作用 ,其E/O值、CTC和 β3分别为 1.71、165和 0 .0 0 0 3 ;Pro + β Cyp复配有协同作用 ,其E/O值、CTC和 β3值分别为1.91、180和 0 .0 0 0 2。结论 有机磷与拟除虫菊酯混剂增效同时也普遍存在增毒问题 ,理想混剂的获得取决于混剂中高比例的高效低毒单剂。

Objective To evaluate the joint action of organophosphorus and pyrethroid pesticides. Methods LD 50 and 95% confidence limits of phoxim(Pho),fenvalerate(Fen),clocythrin(Clo),β-cypermethrin(β-Cyp),profenofos(Pro) and the mixtures(mixed according to ratio of LD 50) of Pho+Fen,Pho+Clo and Pro+ β-Cyp were assessed,using micro-application method for cotton bollworm and Kaber's method for rat respectively.The characteristics of joint action of the pesticide mixtures on SD rat were evaluated by comparative method of the expected and experimental LD 50 values and Logistic regression method,and the co-toxicity coefficient(CTC) of the pesticide mixtures to the cotton bollworm was calculated by Tang's method. Results Three mixtures were of significant additive effects on the larva of cotton bollworm.The CTC values of Pho+Fen,Pho+Clo and Pro+ β-Cyp were 340,797 and 172 respectively.There was a synergistic effect between Pho and Fen(E/O= 2.69,CTC=285,β 3=0.001 5),an additive or a synergistic effect between Pho and Clo(E/O=1.71,CTC=165,β 3= 0.000 3),and a synergistic effect between Pro and β-Cyp(E/O=1.91,CTC=180,β 3= 0.000 2) after these pesticides were mixed. Conclusions The mixtures increase not only insecticidal effect but also toxicity.An ideal pesticide mixture depends upon high proportion of single pesticide with high efficacy and low toxicity in the mixture.