MOLLUSCICIDAL ACTIVITY OF CERTAIN PESTICIDES AGAINST Monacha obstructa montago (FAM:HELICIDAE) LAND SNAILS UNDER LABORATORY AND FIELD CONDITIONS

Laboratory and field experiments have been conducted to evaluate the molluscicidal activity of certain pesticides compared with gastrotox 5 % ( metaldehyede), ( the recommended compound) against monacha obstructa land snails under laboratory and field conditions at plant protection research institute mansoura branch, dakahlia governorate during 2012 season. results can be concluded that the molluscicidal activity of tested compounds under laboratory conditions were arranged in the descending order according to their activity of lc50 values as follows: neomyl > mesarol > kafrothrien > agriflex > koragien > agrinet > nafigator >lambadasen > alfased > drociel > somithion and selian. relative potency compared with gastrotox were (0.75, 0.73, 0.56, 0.33, 0.21, 0.20, 0.12, 0.11, 0.10, 0.07, 0.04 and 0.03 times) for mention before compounds, respectively. data showed that the percent reduction in population of monacha sp. in field after 3 days (i.k) were (65.98, 63.44, 70.22 , 71.28 and 71.27 % ) also, reduction percentages ( residue ) after 28 days were ( 91.39, 78.66, 94.65, 91.55 and 91.48 %) reduction for agrinet, kafrothrien, gastrotox, neomyl and meserol, respectively.