“螺威”植物杀螺剂现场灭螺效果研究与示范IV安徽省东至县江滩现场灭螺效果

Field evaluation of a novel plant molluscicide“Luo-wei”against Oncomelania hupensis IV Molluscicidal effect in field of river beach in Dongzhi County,Anhui Province

目的评价植物杀螺剂4%螺威粉剂(TDS)在长江中下游地区江滩环境的现场灭螺效果,为大规模现场应用提供科学依据。方法在安徽省东至县选择一条垸内沟渠和一片江滩,分别采用2.5 g/m3和5 g/m2TDS进行浸杀法和喷洒法灭螺试验,以2 g/m3和2 g/m250%氯硝柳胺乙醇胺盐(WPN)为对照进行对比观察,统计分析不同环境、不同药物的现场杀螺效果,并对两种药物的成本效果进行分析。结果浸杀1、2、3 d和7 d后,TDS组与WPN组钉螺死亡率均呈逐渐升高趋势,灭螺后7 d TDS和WPN钉螺死亡率分别为94.62%和99.24%,两组间差异无统计学意义(χ2=3.30,P>0.05)。喷洒灭螺1、3、7 d和15 d后,TDS组钉螺死亡率分别为70.82%、79.75%、85.11%和91.65%,WPN组钉螺死亡率分别为77.71%、84.27%、91.90%和95.58%,两组各时点比较差异均有统计学意义(P均<0.05)。每100 m2面积喷洒灭螺,TDS和WPN所需费用分别为316.71元和309.71元,TDS灭螺单位成本略高于WPN。结论TDS在长江中下游江滩现场杀螺的效果已达到国家农业部天然源杀螺剂现场评价要求,需在未来大规模现场试验中对其成本效果开展进一步评价。

Objective To evaluate the field effect of the plant molluscicide＂Luo-wei＂（tea-seed distilled saponins,TDS） against the snail Oncomelania hupensis in the river beach in Anhui Province. Methods The immersing and spraying experiments were carried out in the river beach in Dongzhi County,Anhui Province,to assess the molluscicidal effect of 4% TDS comparing with 50% wettable powder of niclosamide ethanolamine salt（WPN）. The χ 2 test or Fish＇s exact test was used to examine the differences between or among the molluscicidal effects by different environments,molluscicides,application methods,or days after the intervention. Meanwhile,the cost-effectiveness of the two molluscicides was analyzed. Results After 1,2,3 d and 7 d of the immersion,the snail death rates in both TDS group and WPN group increased gradually,the snail death rates in the two groups after immersing for 7 d were 94.62% and 99.24%,respectively,and there was no significant difference between them（ χ 2 =3.30, P 0.05）. After 1,3,7 d and 15 d of spraying,the snail death rates were 70.82%,79.75%,85.11% and 91.65% in the TDS group,and 77.71%,84.27%,91.90% and 95.58% in the WPN group,respectively,and the differences among the snail death rates of the two groups at each time point were statistically significant（all P values 0.05）. The costs of spraying were 316.71 yuan per 100 m 2 for TDS and 309.71 for WPN. Conclusions The molluscicidal effect of TDS has reached the requirements of national standard on nature source pesticides in the river beach of the middle and lower reaches of the Yangtze River. It is necessary to further evaluate its cost-effectiveness in large-scale field experiments in the future.