Health and environmental problems and insect resistance to many of synthetic pesticides clearly indicate that basic research must be directed to the discovery of new safer types of pest control agents in order to insure high production and preservation of plant and animal agricultural product. In recent years increasing attention has been given to the control of pests using plant extracts. Thus, some investigators isolated many toxic natural products from several species of plants which are relatively resistant to insect attack. The cotton leafworm, Spodoptera littoralis (Boisd.) ranks among the most important pests which attack cotton. It is a polyphagous insect, it lives on a wide range of host plant which may markedly differ, both taxonomically and in their chemical composition. In Egypt, recorded 73 host plants for S. littoralis (=Pordenia litura), 16 for oviposition, 45 for feeding and 12 for both purposes. Plants are considered by far the richest source of bioactive organic chemicals (secondary plant metabolites on earth.