Objective To explore a high molluscicidal efficient method in special Oncomelania hupensis snail environments. Methods In 2005 and 2006,in large special environments(rubble creek beaches and seepage barren hills with snails),the me-chanical soil-buried method(excavator digging to bury deep snails)and manual soil-buried method were used respectively,and the results were compared for the cost-effectiveness. Results With the mechanical soil-buried method in 2006,the investment was 0.78 yuan/m2,and the compression rate of snail areas was 100%;with the manual soil-buried method in 2005,the investment was 1.34 yuan/m2,and the compression rate of snail areas was 20.26%. The former was much better than the latter. Conclusion In the large special environments with snails,the mechanical soil-buried method is superior to manual soil-buried method.

Objective To evaluate the molluscicidal effect of black plastic film combined with carbon amide. Methods In Jiangdong Town Jinhua City the field with Oncomelania hupensis in the history was selected as experimental area and divided into 3 groups Group One was administered with black plastic film combined with carbon amide Group Two was administered with simple black plastic film and Group Three was a control group. Results On the 3rd 7th 15th 20th and 30th day after the experiment the mortality rates of O. hupensis of Group One were 86.0% 88.0% 100% 100%and 100%respectively which were significantly higher than those of the control group all P<0.05 . The differences of mortality rates between Group One and Group Two were statistically significant on the 3rd and 7th day after the experiment Group One was superior to Group Two . Conclusion The black plastic film combined with carbon amide can improve the molluscicidal effect.

The mollusicidal effect and toxicity to fish with META-Li in field were tested in mountain areas in Zhejiang Province. The snail control test, which had 3 groups including a META-Li group, niclosamide group and control group, were performed by the spraying method. The adjusted mortalities of snails in the META-Li group on the 3rd, 7th and 15th day were 89.76% , 87.98% and 94.10% , respectively, in the niclosamide group were 89.70% , 83.22% and 94.72% , respectively .and there was no significant difference between the two groups ( P > 0.05), but they were decreased obviously compared with the control group, which were 9.24% , 9.50% and 15.21% , respectively(P <0.05). The toxicity test to fish with META-Li included 3 groups, namely a high concentration META-Li group, low concentration META-Li group and control group, and none fish was dead. It is suggested META-Li has low toxicity to fish, and is suitable to snail control in aquiculture areas.