二嗪磷与B．t制剂混配对小菜蛾的共毒作用

CO-TOXICITY OF DIAZINON AND Bacillus thuringensis FORMULATIONS ON THE DIAMONDBACK MOTH

研究了二嗪磷与Ｂ．ｔ制剂混配对小菜蛾幼虫的共毒作用，结果表明：混配剂在作用前期（２５℃１ｄ，１６℃２ｄ）表现一定程度增效作用，而在作用后期（２５℃２ｄ，１６℃３ｄ）则表现二种单剂的相加作用．当二嗪磷在混配剂中的含量降低或处理温度较低时，前期增效作用更为显著。小菜蛾幼虫龄期对其共毒作用无明显影响。

The co-toxicity of diazinon and Bacillus thuringensis formulations on the diamondback moth (Plutella xylostella L.) was reported in the paper. It was indicated that through a series of mixtures, these two insecticides exhibited evident synergic effect on the larvae of DBM when these larvae were exposed for one day at 25℃ and for two days at 16℃,but they exhibited only additive independent action when the larvae were exposed for two days at 25℃ and for three days at 16℃. There was stronger synergism when proportion of diazinon was lower in the mixture or the treatment temperature was lower. The DBM larval instar and B. t formulations hadn' t evident effect on the co-toxicity pattern described above,which was analysed by comparing the different mechanisms of the two insecticides.