Screening of molluscicides and experimental observation on their molluscicidal efficacy

Objective To screen new molluscicides with high efficiency,low toxicity and easy usage in the fields.Methods Ten kinds of herbicides were screened by soaking,spraying and impregnating for the efficacy in killing snails while fresh water was used as control.Results The molluscicides of Code A-004,B-008 and B-009 showed the molluscicidal efficacy and the LC50 of Code A-004 24h,48h and 72h after experiment were 5.991 mg/L,1.598 mg/L and that of B-008 were 1.699mg/L;5.449 mg/L,2.728mg/L and that of B-0092.257mg/L;5.870mg/L,3.787mg/L and 1.876mg/L.Code B-009 was the only one had molluscicidal efficacy by spraying,and its LC50 3d,7d and 15d after experiment were 4.949g/m2,2.415g/m2 and 1.701g/m2.,respectively.Code A-001 and A-002 had molluscicidal efficacy powder,and the LC50 of both drugs 3d,7d and 15d experiment were 7.112g/m2,2.498g/m2 and 2.020g/m2;4.717g/m2,1.579g/m2 and 1.093g/m2,respectively.Conclusion All the ten kinds of herbicides had more or less molluscicidal efficacy,but their efficacy by spraying and impregnating with doses of under 4.0mg/L(g/m2) were not ideal..Further observation should be conducted on code 001 and 002 as they both showed molluscicidal efficacy by impregnating.