LD_(50)是农药杀虫或杀菌毒力大小测定中的一个极其重要的指标。目前,国内大多数文献只应用其点估计。数理统计学的知识告诉我们:点估计的值等于未知参数的概率一般是等于0;而区问估计则能在一定的概率保 LD_ (50) is an extremely important indicator in the determination of insecticidal or bactericidal virulence of pesticides. At present, most of the domestic literature only applies its point estimation. The knowledge of mathematical statistics tells us that the probability that the value of a point estimate is equal to the unknown parameter is generally equal to 0, while that of a region estimation can be guaranteed at a certain probability