Observation on Long-term Field Moiluscicidal Effects of Rongbao

Objective To investigate the molluscicidal effects of Rongbao on Oncomelania hupensis within a period of I to 210 days when this drug had been used.Methods Rongbao powder was used to kill snails by using spraying and dust- ing methods,and the mortalities of Oncomelania snails were observed in ]d,3d,?d,15d,38d,150d,180d,and 210d after applying the drug.Results The adjusted snails'mortalities within 1 to 210 days in 30 g/m~2 and 50 g/m~2 Rongbao dusting groups were both higher than those of Rongbao spraying group and niclosamide control group.The snails mortalities of 30 g/m~2 Rongbao spraying group within 3 and7 days were both lower than that of the control group(X~2=49.18,P＜0.001).The re- duction rates(82.93%～93.00%)of living snail density after 15～210 days when 30 g/m~2 Rongbao spraying group had been applied were higher than that of niclosamide control group.Conclusion Rongbao has a good molluscicidal effect on On- comelania hupensis in the short-and long-term.