黑色塑料地膜覆盖与未覆盖半年灭螺效果观察

目的观察黑色塑料地膜覆盖半年与未覆盖喷洒氯硝柳胺灭螺效果比较。方法选1条有螺排灌沟分12段,覆盖黑色塑料膜6段分设氯硝柳胺0、2、4、6、8、10 g/m2组;未覆盖6段分设对照,氯硝柳胺2、4、6、8、10 g/m2组,各组试前按系统抽样每组调查7框,捕获框内全部土表钉螺观察。调查后各组按设计用药量加水1 000 m l/m2配制喷洒。试后12个组分别于10、30、90、180d按试前调查方法捕获钉螺观察。结果试后180 d,覆盖各组钉螺死亡率分别为79.07%、70.59%、70.37%、83.54%、78.79%、88.37%;活螺密度比试前分别下降92.74%、94.86%、92.91%、95.89%、94.61%、99.12%。未覆盖各组钉螺死亡率分别为1.20%、12.28%、32.23%、16.00%、37.93%、48.15%,活螺密度分别下降-0.40%、39.02%、50.61%、64.99%、64.72%、79.41%。结论黑色塑料地膜覆盖180d后,钉螺死亡和活螺密度下降率均高于未覆盖各组。覆盖时间越长,活钉螺密度下降越高。未覆盖者反之,时间越长,活螺密度下降越低。

Comparison of Snail Control Effect in Habitat Covered with or without Black Plastic Mulch

Objective To observe effect of snail control in snail habitat covered with or without the black plastic mulch after half a year.Method 12 sections were chosen as the pilot sites from a ditch,and 6 of them,were covered with black plastic mulch,after being sprayed with different concentrations of niclosamide: 0g/m2,2g/m2,4g/m2,6g/m2,8g/m2,10g/m2.And the another 6 sections were spayed with niclosamide of blank,2g/m2,4g/m2,6g/m2,8g/m2,10g/m2 only.Snail survey were made before and 10,30,90,180 days after experiment.Result In 6 sections covered with black plastic mulch,the mortality rate 180 days after experiment of each section was 79.07%,70.59%,70.37%,83.54%,78.79%,88.37%,and the decline rate of living snail density was 92.74%,94.86%,92.91%,95.89%,94.61%,99.12%.However in the 6 sections without black plastic mulch 180 days after experiment,the mortality rate of each group section was 1.20%,12.28%,2.23%,16.00%,37.93%,48.15%, and the decline rate of living snail density was-0.40%,39.02%,50.61%,64.99%,64.72%,79.41%.Conclusion Snail habitat covered with black plastic mulch could significantly increase snail mortality and decrease living snail density.