Molluscicidal activity of Carica papaya and Areca catechu against the freshwater snail Lymnaea acuminata

The molluscicidal activity of seed and lyophilized latex powder of Carica papaya and seed powder of Areca catechu against the vector snail Lymnaea acuminata was studied. The toxicity of these plant products was time and dose dependent. The toxicity of C. papaya lyophilized latex powder (LC50 at 96 h: 8.38 mg/l) was more pronounced than that of A. catechu seed powder (LC50 at 96 h: 12.32 mg/l) and C. papaya seed powder (LC50 at 96 h: 61.56 mg/l). Ethanolic extracts of C. papaya seed and A. catechu seed were more toxic than their other extracts. The ethanolic extract of A. catechu seed (LC50 at 24 h: 17.21 mg/l) was more effective than the ethanolic extract of C. papaya seed (LC50 at 24 h: 53.38 mg/l). The LC50 of column-purified fraction of A. catechu seed at 96 h was 3.99 mg/l, whereas that of C. papaya seed was 7.06 mg/l. C. papaya and A. catechu may be used as potent molluscicides since the concentrations used to kill the snails were not toxic for the fish Colisa fasciatus which shares the same habitat with the snail L. acuminata.