Some Studies on Chemical And Biological Control Of Some Egyptian Snails

Trematodal diseases represent an economic problem allover the world causing inability for work productionbobh in humans or in anemals. Fortunately there is a weekpoint in the life cycle of these parasites where they are obliged to depend on snail hosts during their cycleThus the e1emination ofered the only avilable hope to overcome this denger.During this study we applied some methods of control, including chemical and biological ones, on some freshwater Egyptian snails, LYmnaea oaillaudi, Ph1sa Bcuta, Biomphalaria alexandrina and Bu1inus truncatus snailsIn the case of chemical control we tested Copper sulphate, Bayluscide, Mollutox, and Diklosal. The s~u~showed that Bayluscide was the most effective mo11uscicide, where it gave high mortality rate with low’ concentration, on different snail species except P. acuta snails, whichappear more sensitive to Copper sulphate than other molluscicides.L. caillaudi snail was the more sensitive one for ~l tested mo1luscicides. In this respect we found that snails surviving sublethal dose of the tested molluscicides deposi ting more egg-masses than nonexposed ones. This mcrease or egg-masses have a direct