作者用实验室内连续传代的PR-79株和M株光滑双脐螺(B.glabrata)分别置于氯硝柳胺(70%可湿性粉)和硫酸铜的系列浓度药液中24小时,将所得死亡率资料用机率分析计算程序算出LC_(50)和LC_(90)。然后再将2株双脐螺分别置于上述2种杀螺药LC_(90)的药液中,取其存活者,个别隔离饲养并产生第1代(F_1)。当F_1长到适当大小时,再使之接触这一代螺蛳的LC_(90)药液。存活的F_1再 The authors used serial serial passages of PR-79 and M-strain M. glabrata in a laboratory series in series concentrations of niclosamide (70% wettable powder) and copper sulfate for 24 hours, respectively, LC50 (50) and LC90 (90) were calculated using probability analysis and calculation program. Then, 2 strains of Umbilicaria were placed in the above two kinds of liquid LC_ (90) of the liquid, take the survivors, isolated and reared individually and produce the first generation (F_1). When F_1 grows to the proper size, it is exposed to LC_ (90) liquid of this generation of snails. Surviving F_1 again