目的 研究适合灌渠灭螺的新方法及技术规范.方法 试验渠采用4%氯硝柳胺乙醇胺盐粉剂连续3次进行喷粉灭螺,同时设对照组,平行观察灌渠活螺框率、活螺平均密度、钉螺死亡率变化,对喷粉灭螺频次及效果进行分析评价.结果 试验渠第1轮喷粉灭螺后3～15 d活螺密度下降90%以上,第2、3轮后下降99%以上;喷粉灭螺第2、3轮后3～15 d平均活螺框率、钉螺死亡率与第1轮有显著差异,而第2轮与第3轮无显著差异.喷粉灭螺第3轮后30、90 d灭螺效果仍保持良好.试验渠和对照渠各观察指标差异均有统计学意义.结论 4%氯硝柳胺乙醇胺盐粉剂喷粉灭螺法是灌渠灭螺的有效方法,实际应用时喷粉灭螺频次宜连续2～3次.“,”Objective To study a new method and technical specification for Oncomelania snail control in irrigation canals.Methods Four percent niclosamide ethanolamine salt dustable powder was dusted in a test canal three times continuously,and a control canal was set up at the same time.The molluscicidal frequency and effect of niclosamide ethanolamine salt powder was observed and the results,including the change of living snail frames,average density of living snails and mortality of snails,were analyzed.Results Between the third and fifteenth day after the first dusting in the test canal,the reduction rate of the density of snails was more than 90% and after the second and third dusting,the reduction rate was more than 99%.For the average rates of living snail frames and mortality of snails,there were significant differences between the first dusting and later two dustings,while there was no significant difference between the second dusting and the third dusting.On the thirtieth and ninetieth day after the third dusting,the effect of snail control was still satisfactory.There were significant differences between the test canal and control canal about all the observation indexes.Conclusion The application of 4% niclosamide ethanolamine salt dustable powder is efficient in the snail control in irrigation canals,and the suitable frequency of dusting is 2 or 3 times.