有螺环境分段定级现场查螺方法探讨

目的探讨有螺环境按钉螺密度高低分段定级现场查螺方法的优劣,提高查螺效率,降低查螺成本。方法选择江陵县廖堤村和熊堤村为试验村,对其有钉螺环境按500 m为段进行分段,采用系统抽样法,以50 m和10 m设框分别对两村进行调查。比较两种方法查螺的效果和效率。结果对两村共39段有螺环境进行调查,10 m设框调查2 584框,活螺平均密度2.040 6只/0.1 m2;50 m设框调查539框,活螺平均密度2.606 7只/0.1 m2。相同地点两方法查螺查出的钉螺级别差异无统计学意义(χ2=2.578 9,P0.05),但10 m设框调查所用工时是50 m设框调查所用工时的近3倍。结论在有螺环境中采用分段定级的查螺模式可节省查螺时间和人力资源,提高工作效率,同时也可掌握有螺环境螺情的分布现状等优点。

Field survey of Oncomelania by sectioning method

Objective To explore the advantage and disadvantage of oncomelania snail field survey by dividing the area into sections, and improve the efficiency of oncomelania snail survey and reduce the cost. Methods Liaodi Village and Xiongdi Village of Jiangling County were chosen as the pilot site. The area of survey was divided into 500 meter sections. Systematic sampling was applied to set quadrasi at 50 m or 10 m intervals to survey the soil of two villages. The efficiencies of two methods were compared. Results Totally 39 sections of snail detected environment were surveyed. 2584 quadrasi are obtained in 10 minterval sampling, and the average density of the lived snail was 2.040 6 per 0.1 square. 539 quadrasi were obtained in 50 m interval sampling, and the average density of the lived snail was 2.606 7 per 0.1 square. There was no significant difference between the two methods. But the time used by 10 m interval sampling was nearly three times of that by 50 m interval sampling. Conclusion The field survey that cutting the detected snail environment into sections is more efficient and cost effective, and can determine the distribution of the oncomelania snail in the detected environment.