Abstract

The present investigation aims to throw light on the effect of methylene chloride and normal hexane extracts of Azadirachta indica, Citrullus colocynthis, Ammi majus and Mentha microphylla on the 4^thlarval instar of the cotton leaf worm, Spodoptera littoralis under laboratory conditions. The results showed that the methylene chloride extract of A. indica, C. colocynthis are the most potent extracts against S. littoralis larval. The present study was also extended to conduct the insecticidal effect of the most potent extracts A. indica, C. colocynthis methylene chloride extract post formulation on S. littoralislarval. Marked biochemical changes however, being recognized in pest as marked decrease in total lipids, total protein and glucose contents. The activity of both ALAT and ASAT are also being highly affected. The tested dose levels also, showed highly histopathological disturbances in the midgut and body wall cells of this pest. Among the most recorded observations are vacuolation, destruction of the cells.

Key words: Cotton leaf worm (Spodoptera littoralis), Azadirachta indica, Citrullus colocynthis, Ammi majus, Mentha microphylla plant, biochemical and histopathological studies.