氯代水杨胺在血吸虫病疫区8省现场灭螺效果评价

Evaluation on molluscicidal effect of chlorosalicylicamide on Oncomelania hupensis in schistosomiasis endemic areas of eight provinces in China

目的评价10%氯代水杨胺可湿性粉剂（LDS）在我国主要血吸虫病疫区现场杀灭湖北钉螺效果。方法在云南、四川、湖南、湖北、江西、安徽、江苏、浙江等8省选择有螺环境,开展LDS现场浸杀、喷洒和喷粉灭螺试验。现场浸杀法：将LDS配成有效含量分别为0.1、0.2、0.4、0.6、0.8、1.0 g/m^36个浓度组,同时设50%氯硝柳胺乙醇胺盐（WPN）有效含量为1.0 g/m^3对照组和空白对照组（清水）,分别观察LDS现场浸杀湖北钉螺24、48、72 h灭螺效果;现场喷洒法和喷粉法：将LDS配成有效剂量分别为0.2、0.4、0.6、0.8、1.0 g/m^25个浓度组,同时设1.0 g/m^2WPN对照组和空白对照组（清水）,分别观察LDS现场喷洒及喷粉后1、3、7 d的灭螺效果。结果 0.1 g/m^3LDS在四川、江西、江苏、浙江,0.2 g/m3LDS在云南、湖南、湖北,0.4 g/m^3LDS在安徽现场浸杀钉螺72 h,钉螺死亡率均〉95%;0.2 g/m^2LDS在湖南、湖北、江西、浙江,0.4 g/m^2LDS在四川、安徽,0.6 g/m^2LDS在云南、江苏现场喷洒后7 d,钉螺死亡率均〉85%;0.6 g/m^2LDS在云南、四川、湖北、江西、安徽、江苏、浙江7省现场喷粉后7 d,钉螺死亡率均〉85%。按照《农药登记用杀钉螺剂药效试验方法和评价》（NY/T 1617-2008）中的标准,LDS为合格灭螺药。结论 LDS现场浸杀、喷洒或喷粉均有较好的杀螺效果,适用于我国血吸虫病流行区各种有螺环境灭螺。现场使用推荐剂量：浸杀法为0.1~0.2 g/m^3,喷洒法为0.2~0.4 g/m^2,喷粉法为0.4~0.6 g/m^2。

Objective To evaluate the effects of a novel molluscicide,the salt quinoid-2′,5-dichloro-4′-nitrosalicylanilide from niclosamide（LDS）,with 10% wettable powder,in main schistosomiasis epidemic areas of China,including Hunan, Jiangxi, Hubei, Anhui, Jiangsu, Sichuan, Yunnan and Zhejiang Province. Methods In the immersion test,6 effective concentrations of 10% LDS were tested respectively：0.1,0.2,0.4,0.6,0.8,1.0 g/m3 in the field;at the same time,50%wettable powder of niclosamide ethanolamine salt（WPN）with effective concentrations of 1.0 g/m3 was used as the molluscicide control,and the fresh water as the blank control,then the mortality rates of O. hupensis snails were recorded at 24 h,48 h and 72 h after the immersion. In the spraying test and powder-spraying test,5 effective dosages of 10% LDS were tested respectively：0.2,0.4,0.6,0.8,1.0 g/m2,while 50% WPN 1.0 g/m2 was used as the molluscicide control,and the fresh water as the blank control in the field for 1 d,3 d and 7 d,then the mortality rates of O. hupensis snails were recorded at 1 d,3 dand 7 d after the spraying and powder-spraying. Results The snail mortality rates of LDS using the immersion test for 72 h were more than 95% in the field of eight provinces（0.1 g/m3 in Sichuan,Jiangxi,Jiangsu and Zhejiang provinces,0.2 g/m3 in Yunnan,Hunan and Hubei provinces,and 0.4 g/m3 in Anhui Province）;the snail mortality rates of LDS using the spraying test for 7 d were more than 85%（0.2 g/m2 in Hunan,Hubei,Jiangxi and Zhejiang provinces,0.4 g/m2 in Sichuan and Anhui provinces,0.6 g/m2 in Yunnan and Jiangsu provinces）. The snail mortality rates of LDS the powder-spraying test for 7 d were more than 85%（0.6 g/m2 in Yunnan,Sichuan,Hubei,Jiangxi,Anhui,Jiangsu and Zhejiang provinces）. According to the standards of＂Efficacy test methods and evaluation of molluscicide for pesticide registration（NY/T 1617-2008）＂,LDS is a qualified molluscicide. Conclusions LDS has good molluscicidal effects through the immersion,spraying and powder-spraying test in the fields. It is suitable for a variety of environments to control O. hupensis snails of schistosomiasis endemic areas in China. The recommended dosages of LDS are 0.1-0.2 g/m3 by the immersion method,0.2-0.4 g/m2 by the spraying method,and 0.4-0.6 g/m2 by the powder-spraying method in the fields.