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STUDIES ON NEEM SEED KERNEL EXTRACTS AS OVIPOSITION DETERRENTS AND OVICIDAL COMPOUNDS FOR THE COTTON LEAF WORM MOTHS, Spodoptera littoralis (Boisd.) Texte intégral
2009
H.A Gomaa
Mated female moth of the cotton leafworm, S. littoralis laid a total number of 1564.22 eggs during its whole life. In a free choice test, treating N. oleander leaves (as an oviposition site) with an aqueous extracts of neem seed kernel solutions extracted by different organic solvents reduced the number of deposited eggs on it. The lowest number of eggs was recorded when methanol was used for extraction, followed by chloroform, and the highest was, however, obtained after using benzene, butanol and ethyl acetate. The number of deposited eggs decreased as the concentration of any tested neem extract increased to reach the minimum at 0.2%. This means that the most deterred neem seed kernel extract is that which extracted with methanol at the concentration of 0.2%.Hatchability percentage of S. littoralis eggs greatly affected by the type of organic solvents used for neem extraction and the concentration of each extract on treated N. oleander leaves. The lowest hatchability was recorded after using methanol, followed by chloroform.On the other hand, an increase in neem seed kernel extract concentration caused an obvious decrease in egg hatchability.
Afficher plus [+] Moins [-]ISOLATION AND IDENTIFICATION OF AN ACARICIDAL GLYCOSIDE FROM Acacia saligna LEAVES Texte intégral
2009
A.M Moussa | A.M Emam | M.A. Mohamed | A.E Mohamed
as sources of biologically active secondary metabolites including pesticides because of their eco-friendly nature. The present study indicated that the ethylacetate extract of the Acacia saligna leaves exhibited acaricidal activity against the phytophagous twospotted spider mite ( Tetranychus Urticae Koch ). The chromatographic separation methods led to isolation of a pure compound from Acacia saligna leaf ethylacetate extract which exerted acaricidal action against the tested mite with LC50 value of 74.13 mg.l-1 after 48 h. Based on chemical (acid hydrolysis) and spectroscopic (1H, C13- NMR and MS) methods, the isolated compound was identified for the first time from plants as 2-hydroxymethyl-9-hydroxy-9-methyl-undecanyl (O-α-L-arabinopyranosyl-β-D-galactopyranoside.
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