Abstract:

  Objective  To evaluate the molluscicidal effect of a novel molluscicide of quinoid- 2  ,
5-dichloro-4'-nitrosalicylanilide, LDS. Methods  The parallel experiment with LDS and
niclosamide,WPN was carried out by means of immersion, insufflations and powdering in lab and
the field and there were seven concentrations of 0. 05, 0. 1, 0. 2, 0. 4, 0. 8, 1. 6, 3. 2 mg/L(g/m²)
in lab and three dosages of 0. 2, 0. 4, 0. 8 mg/L(g/m²) in the field. The molluscicidal effects of 24,
48, 72 h and l, 3, 7 d mortality of the Oncomelania snails were investigated with the dosage of 0. 4
mg/L(g/m²) for both of the molluscicides. Results   Under the room temperature of 23-25 'C , for
exposure 72 h by the immersion method, the snail death rates of LDS and WPN were 100. 0% and
96.7%, respectively; for exposure 7 d by the insufflations method, the snail death rates were
100. 0% and 96. o% , respectively; for exposure 7 d by the powdering method, the snail death rates
were 92. o% and 94. 0%, respectively in lab.  Under the field temperature of 15-24 'C , for expo-
sure 72 h by the immersion method, the snail death rates of LDS and WPN were 100.0% and
96.0%, respectively; for exposure 7 d by the insufflations method, the snail death rates were
100.0% and 96.9%, respectively; for exposure 7 d by powdering method, the snail death rates
were 100. 0% and 94.1%, respectively in the field.  Conclusions   The parallel experiment of LDS
and WPN by the three methods shows that their molluscicidal effects are basically the same in lab
and the field. However, the cost of LDS is less than that of WPN.

Key words:  Molluscicide, LDS, Molluscicidal effect, Oncomelania snail

摘要：

 目的观察新型灭螺剂氯代水杨胺(LDS)的灭螺效果。方法采用浸杀法、喷洒法和撒粉法，将10% LDS和50%氯硝柳胺乙醇胺盐(WPN)在实验室分别配成0.05、0.1、0.2、0.4、0.8、1.6、3.2 mg/L (g/m2)7个浓度，在现场分别配成0.2、0.4、0.8 mg/L (g／m²)3个浓度，平行比较两种药物实验室24、48、72 h和现场1、3、7d的灭螺效果。两种药物均以0.4 mg/L (g/mz)浓度评价其灭螺效果。结果  在实验室温度23-25℃条件下，LDS和WPN的钉螺死亡率，浸杀72 h分别为100. 0%和96.7%；喷洒7 d分别为100.0%和96.0%；撤粉7d分别为92.0%和94.0%。在现场温度15-24℃条件下，LDS和WPN的钉螺死亡率，浸杀72 h丹别为100.0%和96.0%；喷洒7d分别为100.0%和96.9%；撒粉7d分别为100.0%和94.1%。结论新型灭螺剂氯代水杨胺的灭螺效果与氯硝柳胺乙醇胺盐基本相同，但灭螺费用降低。

关键词:  灭螺剂；氯代水杨胺；灭螺效果；钉螺