氯硝柳胺悬浮剂杀螺效果评价

目的 评价25％氯硝柳胺悬浮剂(SCN)的实验室和现场杀螺效果。方法 在实验室和现场采用浸杀法和喷洒法进行SCN和50％氯硝柳胺乙醇胺盐可湿性粉剂(WPN)两种剂型的杀螺试验。结果 实验室SCN 0.5mg/L(有效浓度0.125mg/L)和WPN 0.5mg/L(有效浓度0.25mg/L),浸杀24h,钉螺死亡率均为100％;有效浓度0.063mg/L浸杀24h,钉螺死亡率SCN为80.0％,WPN为66.7％。喷洒SCN 0.5g/m~2和WPN 1.0g/m~2,钉螺死亡率均为100％。现场浸杀SCN 0.5mg/L和WPN 1.0mg/L的钉螺死亡率均为100％。现场喷洒SCN 2.0g/m~2和WPN2.0g/m~2,SCN有效成份含量为WPN的1/2,3d和7d杀螺效果均高于WPN(x_(3d)~2=30.21,P<0.01;x_(7d)~2=7.62,P<0.01),差异均有非常显著性;15d杀螺效果相近(x_(15d)~2=0.02,P>0.05)。SCN1.0g/m~2与WPN 2.0g/m~2喷洒,SCN有效成份含量为WPN的1/4,杀螺效果相近(x_(3d)~2=0.90,P>0.05;x_(7d)~2=1.99,P>0.05;x_(15d)~2=0.03,P>0.05)。结论 现场SCN浸杀和喷洒有效药物剂量为WPN的1/4时,均能达到与WPN相同的杀螺效果,SCN是一种高效、使用方便、水溶性好的新型杀螺剂,值得在现场推广应用。

EXPERIMENTS OF MOLLUSCICIDAL EFFECT OF SUSPENSION CONCENTRATE OF NICLOSAMIDE AGAINST ONCOMELANIA SNAILS

Objective To evaluate the molluscicidal effects of suspension concentrate of 25% mclosamide (SCN) against Oncomelania snails in laboratory and field. Methods The experiments with SCN and wetlable powder of 50% niclosamide ethanolamine salt (WPN) against the snails by immersion and spraying methods respectively were performed in laboratory and field. Results In laboratory, by immersion method for 24 hours, the death rate of snails using SCN with 0. 125 mg/L of concentration of niclosamide was 100%. while the death rate of snails using WPN with 0. 25 mg/L of concentration was 100%. By immerion in 0. 063 mg/L of SCN and WPN, the death rates were 80. 0% and 66. 7% respectively. By the spraying method with 0. 5 g/m2 of SCN or 1. 0 g/'m2 of WPN for 24 hours, the death rates of snails were both 100%. In the field, by the immersion method for 1 day, the death rates of snails with 0. 5 mg/L SCN (active concentration of niclosamide was 0. 125 mg/L) and with 1.0 mg/L WPN (active content was 0. 5 mg/L) was both 100%. By the spraying for 3, 7, 15 days, the molluscicidal effect of 2. 0 g/m2 SCN (active content was 0. 5g/m2) were better than that of 2. 0 g/rn2 WPN (active content was 1. 0 g/m2). There were siginificant differences between 2. 0 g/m2 SCN and 2. 0 g/m2 WPN for 3 days and 7 days (X_3~2d= 30. 21,P<0. 01 ; X_7~2d = 7. 62,P<0. 01), no siginificant difference for 15 days (X_15~2d = 0. 02. P > 0. 05). There were no siginificantly different molluscicidal effects between 1. 0 g/m2 SCN and 2. 0 g/m2 WPN for 3, 7, and 15 days(X_3~2d = 0. 90,P>0. 05;X_7~2d=1.99,P>0. 05;X_15~2d = 0. 03,P>0. 05), Conclusion There was the same molluscicidal effect while the active content of SCN was a guarter of active content of WPN by immersion and spraying in the field. SCN is a novel form of niclosamide with high molluscicidal effect and of convenience to use in the field.