江湖洲滩钉螺生存繁殖的现场实验观察

FIELD OBSERVATIONS ON SURVIVAL MULTIPLICATION OF ONCOMELANIA SNAILS IN MARSHLAND OF YANGTZE RIVER

本文报告以长江中下游鄂、湘、赣、皖,苏五省钉螺为观察样本,用现场螺笼饲养钉螺的控制实验方法,比较观察五地钉螺在南京江滩上生存繁殖情况,结果五地钉螺生存率间有非常显著差异,且各地生存规律都为Logistic曲线类型,结合五地钉螺的产卵数,螺卵孵化率,幼螺成活率等观察数据,认为长江中下游的异地钉螺能在南京江滩上生存繁殖,但以近距离洲滩间钉螺扩散的危害性较大.根据钉螺生存曲线和产卵分布情况,提示最佳灭螺时间为5～6月份.

In order to detect the survival and multiplication of Oncomelania Snails after their moving to new habitats along Yangtze River, field observations were made in the marshland near Nanjing from December 1986 to December 1987. Experiments with caged snails collected from Hubei, Hunan, Jiangxi, Anhui and Jiangsu provinces were carried out. Results demonstrated that snails from different areas along Yangtze River can live and repioduct in the marshland near Nanjing. However, the nearer the distance which snail can move, the greater the harmfulness will be done in tiansmission in the lower reaches of Yangtze River. Results also showed that the alternation of snail generation occured in July and August. It suggested that the measures of snail control will be most effectively carried out in May and June.