Repellency effect of 2.8 plant extracts obtained from different parts of 13
indigenous plants was investigated against Monacha cantiana Land snails, using one     and two choice feeding methods.,                                                                                        . AU plant materials either extracted with hexane and/or ethanol showed a
considerable snail repellency effect, when their' crude extracts were tested using one    . choice feeding methods In contrast results of two choice feeding test method indicated that all the
tested plant extracts 'showeo snail. repellant 'effect except Damsisa, Enabeddip Calotropis and Geranium hexane.crude extracts, which failed to achieve 50% or more . repellency level. Rso values of the pronounced crude plant extracts were evaluated, . whereby, Harrnala ethanol extract induced the highest repellency effect against M. cantiana snails, followed by Khella hexane extract, Khella ethanol extract and Santonica hexane extract. Crude plant extracts have been preliminary screened frr their molluscicidal
activity, Results revealed that some extracts exhibited low and/or moderate mortality percentages, while the:·Otti~rfailedJo induce snail mortality, this trend could be attributed to Other,; repellency effect againstsnails. . The candidate crude plant extracts; i.e. (Khella and Santonica hexane extracts)
and (Khella and' Harmala ethanol extracts), were subjected to definitive screening for
evaluate their LCse values against snails. Results showed that Khella ethanol extract
exhibited the highest toxic effect followed by Santonica hexane, Khella hexane and
Harmala ethanol extracts. Data concerning the repellency effect of the tested pesticides against snails
showed that Osbac was the superior one followed .by Nabu-s, Topsin-M, while
Lebaycide was the least. The molluscicidal activity of the tested pesticides was also investigated. Topsin-M exhibited the highest toxic action against snails, followed by Osbac,
Lebaycide and Nabu-s. The obtained results varied in there activity according to the
type of solvent used in extraction processes and plant chemical constituents content
of recognized molluscicidal activity.