Molluscicidal Potential Of Lantana Indica And Alstonia Scholaris Plants Against Freshwater Snail Lymnaea Acuminata
Published 2009 · Biology
Laboratory evaluation was made to assess the molluscicidal activity of acetone extracts of Alstonia scholaris (familyApocynaceae) and Lantana indica (familyVerbenaceae) leaf against freshwater snail Lymnaea acuminata. This snail is intermediate hosts of liverfluke, Fasciola hepatica and Fasciola gigantica, which causes endemic fascioliasis in cattle and livestock. The toxic effect of both the plants extracts was time as well as dose dependent. There was a significant negative correlation between LC values and exposure periods, thus the LC50 values of Alstonia scholaris leaf acetone extract (ASLAE) was decreased from 25.05 mg/L (24h) to 15.32 mg/L (96h), and from 06.01 mg/L (24h) to 01.31 mg/L (96h) in the case of Lantana indica leaf acetone extract (LILAE). Binary mixture of Lantana indica leaf acetone extract (LILAE) + Alstonia scholaris leaf acetone extract (ASLAE) in 1:5 or 1:1 ratio also shows significant synergistic effect against Lymnaea acuminata. Sub-lethal exposure (20% and 40% of LC50 of 24h) of LILAE and ASLAE either individually or in binary combinations, caused significant reduction in the fecundity, hatchability (of eggs) or survival of the hatchlings (hatched young snails) in comparison to control group. On the other hand exposure of sub-lethal doses of this extract also shows significant time and dose dependent alterations in the level of total protein, total free amino acids, glycogen, nucleic acids and the activity of enzyme protease in nervous and hepatopancreas tissue of snail Lymnaea acuminata. Seven days withdrawal experiment shows, there was highly significant (p<.05) recovery in all the biochemical parameters in both the tissues of snail. Conclusion: Therefore, acetone extract of leaf of Alstonia scholaris and Lantana indica leaf may eventually be of great value for the control of harmful aquatic snails and other molluscan pests.