Abstract: Objective To study the effects of film mulching on Oncomelania hupensis and its eggs in soil. Methods The damp ridges with O. hupensis snails were selected and divided into niclosamide/film mulching group (sprayed with 50% wettable powder of niclosamide ethanolamine salt at 2 g/m2 and covered with mulch), film mulching group (covered with mulch without niclosamide spraying), and control group (not treated by molluscicidal measures). Snail investigation was conducted in different soil layers (0, 0-2, 2-5, 5-10, and 10-15 cm) at 40 d after niclosamide spraying plus film mulching and at 90 d after film mulching alone. Results At 40 d and 90 d after film mulching, the snail distribution in soil changed, increasing by degrees from soil surface to the deep layer of soil (R2＝0.9877; R2＝0.7619); compared with those of control group, the mortality of snails in soil was significantly higher (χ2＝281.198, P＜0.001; χ2＝47.970, P＜0.001), the average density of living snails was significantly decreased (Z＝-6.390, P＜0.001; Z＝-4.681, P＜0.001), and the number of young snails was lower (Z＝-6.733, P＜0.001; Z＝-5.131, P＜0.001). Conclusion Film mulching is effective in killing snails in soil and can control the reproduction and breeding of the second generation of snails.

Key words: Schistosomiasis, Oncomelania hupensis, Mulch, Niclosamide, Reproduction, Distribution

摘要： 目的 观察农用地膜覆盖灭螺对土内钉螺和螺卵的影响。方法 选择潮湿的有螺田埂作为试验现场, 分设施药覆膜组(采用50%氯硝柳胺乙醇胺盐可湿性粉剂, 按2 g/m2的剂量喷洒后覆盖地膜)、单纯覆膜组(不施药直接覆盖地膜)和对照组(不采取任何灭螺措施)。于施药覆膜后40 d和单纯覆膜后90 d分别对试验环境0、0～2、2～5、5～10和10～15 cm的土层进行钉螺调查。结果 覆膜40 d和90 d后, 钉螺在土内分布的特点发生了改变, 钉螺由土表向土内深层呈逐渐递增趋势(R2＝0.9877, R2＝0.7619), 土内钉螺死亡率高于对照组(χ2＝281.198, P＜0.001;χ2＝47.970, P＜0.001), 活螺平均密度较对照组均有下降(Z＝-6.390, P＜0.001;Z＝-4.681, P＜0.001), 幼螺的数量明显低于对照组(Z＝-6.733, P＜0.001;Z＝-5.131, P＜0.001)。结论 地膜覆盖对土内钉螺有很好的杀灭作用, 并且可抑制钉螺第2代的繁殖和孳生。

关键词: 血吸虫病, 钉螺, 农用地膜, 氯硝柳胺, 繁殖, 分布