چکیده (انگلیسی):

The cotton leaf worm, Spodoptera littoralis, is a major pest in Egypt causes severe quantitative and qualitative losses of cotton and other economic crops. This study examines the effect of Caltropis proceraa and Atriplex halimus extracts on the 4nd instar larvae. This study was carried out to identify the effect plant extracts on biochemical parameters and differential and total haemocyte counts of S. littoralis after treated with LC25 of Caltropis proceraa and Atriplex halimus extracts for 48 hours (treated with each extract in separate). Marked biochemical changes, however, being recognized in pest as marked decrease in total lipids, total protein and glucose contents. The activities of both aspartate amino transferase (ASAT) and alanine amino transferase (ALAT) are also being highly affected. Four types of haemocytes marked by; prohaemocytes (PRs), plasmatocytes (PLs), granulocytes (GRs) and oenocytoids (OEs). The percentage of PRs decreased in insects fed on leaves treated with Caltropis proceraa and Atriplex halimus plant. The percentage of PLs increased, while the percentage of GRs decreased in all tested insects treated. The percentages of oenocytoids (OEs) increased in insect fed treated compared with control. Results indicated that total Haemocyte Counts (THCs) of insects fed on leaves treated significantly decreased in all insects treated.