Joint Action of Two Pesticides and an Oxidase Inhibitor on The Snail Lymnaea Acuminata

Studies were conducted on synergism between an Organophosphate, Nuvan (dichlorvos) mixed with a carbamate, Sevin (carbaryl) in a 1:46 ratio against the snail Lymnaea acuminata. It was found that Sevin enhances the activity of Nuvan and thus the LC values ( LC10, LC50, LC90 ) obtained from this mixture were low as compared to Nuvan or Sevin alone. The acetylcholinesterase (AChE) inhibition was higher in case of Nuvan + Sevin (16.17%) as compared to Nuvan or Sevin (34.7% , 69.1%) alone. When Piperonyl Butoxide (PB), a mixed function oxidase inhibitor was given with Nuvan and Sevin in a 1:46:5 ratio, the LC value decrease still further. It appears that, in the tertiary mixture, while PB reduce the oxidative detoxification of Nuvan and Sevin the carbamate may also be preventing the hydrolysis of Nuvan may tertiary mixture lethal than of its components.

EFFICACY OF BINARY COMBINATION OF DELTAMETHRIN+MGK-264 ON LEVELS OF BIOCHEMICAL CHANGES IN THE SNAIL LYMNAEA ACUMINATA

Objective: The objective of the present study is the evaluation of the effect of the sublethal (40% and 60% of 48h LC50) binary combination (1:5 ratios) of molluscicides deltamethrin+MGK-264 on the endogenous levels of protein, amino acid and nucleic acid in different tissues of snail Lymnaea acuminata. Methods: The snails were treated with 1:5 mixtures of sub-lethal concentration of (40% and 60% of 48h LC50) deltamethrin+MGK-264 on the protein, amino acid and nucleic acid levels in gonadal, nervous and foot tissue of L. acuminata. In order to study the effect of withdrawal from treatment, the snails were first exposed to the above concentrations for 96h, after which they were transferred to freshwater. Water was changed every 24h for the next seven days, after which different biochemical parameters were estimated. Results: There was a significant change in the levels of protein (sublethal concentration of 60% of 48h LC50 after 96h) gonadal, nervous and foot tissues are 48.1, 12.1 and 14.5%, respectively, amino acid are 273, 234 and 252%, respectively, DNA are 25.1, 38.9 and 42.1%, respectively and RNA are 12.2, 30.7 and 30.5%, respectively. These changes were time and concentration-dependent. In the withdrawal experiment, the snails were treated for 96h to transfer in freshwater for 7 d, which caused significant recovery in all the biochemical parameters. Conclusion: The present study concluded that the high molluscicidal activity of deltamethrin+MGK-264 simultaneous decrease in the levels of proteins, DNA, RNA and increase in the level of amino acids.