Molluscicidal effect of ether extract of Azadirachta indica (neem) on experimentally reared snails Lymnaea auricularia and Indoplanorbis exustus

The molluscicidal effect of ether extract of different components of neem plant (leaf, seed, bark and whole plant) was evaluated against snails Lymnaea auricularia and Indoplanorbis exustus. The extracts were prepared by cold extraction method. The concentrations of extracts used were 1:10, 1:15, 1:20, 1:25, 1:30 and 1:35 and the results were recorded at different period of exposure time (6, 12, 24, 48, 72 and 96 h). The different concentrations of ether extract of neem showed variable effect on adult stages of L. auricularia and I. exustus. It showed positive correlation between exposure time and mortality and negative correlation between dilution and mortality. Among the different extracts, the whole plant extract was most effective followed by seed, leaf and bark against snails. I. exustus was found to be more susceptible to methanolic extract of neem as compared to L. auricularia.