Insecticidal and Fungicidal Activity of Ulva lactuca Linnaeus (Chlorophyta) Extracts and their Fractions

The insecticidal and fungicidal activities of acetone, chloroform, ethanol, methanol and petroleum ether extracts of Ulva lactuca was tested against mosquito larvae, Culex pipiens and cotton leafworm, Spodoptera littoralis and three phytopathogenic fungi: Aspergillius niger, Penicillium digitatum and Rhizoctonia solani. The results indicated that the acetone extract was the most potent extract against C. pipiens however ethanol and chloroform extracts were most active as larvicides against S. littoralis. Methanol and ethanol extracts showed the highest pupation inhibition (%) of cotton leafworm, however, petroleum ether and methanol extracts were the most potent inhibitors for adult emergence and larval growth. Results of the antifungal activity indicated that methanol extract was the most potent against A. niger, P. digitatum and R. solani. The most potent methanolic extract was fractionated over silica gel column chromatography. All of the resulted fractions were tested for their antifungal activity. Fraction 7 (methanol 100%), exhibited more antifungal activity against all of the tested fungi.