目的了解不同月份钉螺对氯硝柳胺乙醇胺盐可湿性粉剂(WPN)的敏感性,为制定杀螺药筛选与药效评价标准化方法提供参考依据。方法自2010年6月至2011年5月每月采集江苏省镇江市江滩钉螺,实验室饲养24h后随机分组,用现配制的WPN药液在温度(25±1)℃、湿度60%、光照充足的培养箱内对上述钉螺进行浸杀试验,采用敲击法鉴别钉螺死活并计数,计算钉螺死亡率及其半数致死浓度(LC50)。结果 0.5mg/L及以上浓度WPN浸杀钉螺24h,各月采集的钉螺死亡率均为100%;浓度为0.25mg/L时,钉螺死亡率为60%～100%;浓度为0.125mg/L时,钉螺死亡率为3%～27%;浓度为0.0625mg/L时,钉螺死亡率为3%～20%;0.032mg/L及以下浓度钉螺死亡率均为0;浸杀24h钉螺LC50为0.140～0.209mg/L。0.5mg/L及以上浓度WPN浸杀钉螺48h,各月采集的钉螺死亡率均为100%;浓度为0.25mg/L时,钉螺死亡率为90%～100%;浓度为0.125mg/L时,钉螺死亡率为3%～57%;浓度为0.0625mg/L时,钉螺死亡率为3%～13%;浓度为0.032mg/L时,钉螺死亡率为0～10%;0.016mg/L及以下浓度时,钉螺死亡率均为0;浸杀48h钉螺LC50为0.112～0.170mg/L。不同月份钉螺经WPN浸杀24h与48h时的死亡率差异均无统计学意义(P均>0.05)。结论全年不同月份采集的钉螺对WPN的LC50波动范围不大,敏感性变化较小,对杀螺药筛选以及药效评价结果影响有限,在实验误差范围内。 Objective To understand the susceptibility of snails to niclosamide ethanolamide WP (WPN) in different months and provide a reference for formulating the standardization method of snail screening and efficacy evaluation. Methods Oncomelania hupensis was collected from Zhenjiang City, Jiangsu Province every month from June 2010 to May 2011. The rabbits were randomly divided into four groups after being incubated for 24 hours at a temperature of 25 ± 1 ℃, a humidity of 60% The sucking snails were immersed in a well-illuminated incubator. The periwinkle snails were identified by percussion method and counted. The mortality and the median lethal concentration (LC50) of the snails were calculated. Results The snails fed with WPN of 0.5 mg / L and above were immersed in snails for 24 h, and the mortality of snails collected in each month was 100%. The mortality of snails was 60% -100% at the concentration of 0.25 mg / L and 0.125 mg / L , The mortality of snails was 3% -27%; the mortality of snails was 3% -20% at the concentration of 0.0625mg / L; the mortality of snails was 0.032mg / L and below; 0.140 ~ 0.209mg / L. Snail snails were immersed for 48h in the concentrations of 0.5mg / L and above WPN, and the mortality of snails collected in each month was 100%. When the concentration was 0.25mg / L, the mortality of snails was 90% -100%; when the concentration was 0.125mg / L , The mortality of Oncomelania snails was 3% -57%; the mortality of Oncomelania snails was 3% -13% at the concentration of 0.0625mg / L; the mortality of Oncomelania snails was 0-10% at the concentration of 0.032mg / L; And the following concentrations, snail mortality were 0; 48h snail LC50 was 0.112 ~ 0.170mg / L. There was no significant difference in the mortality of snails treated with WPN for 24 h and 48 h (P> 0.05). CONCLUSIONS The LC50 of Oncomelania snail collected from different months of the year had a small range of LC50 fluctuation and little change of sensitivity, which had a limited impact on the screening and efficacy evaluation of M. sphaerotheca and within the experimental error range.