QUALITATIVE DIFFERENTIAL HAEMOCYTE COUNTS IN HEALTHY AND PARASITIZED LARVAE OF SPODOPTERA LITTORALIS (BOISD.) AFTER INSECTICIDE TREATMENTS

Larvae of Spodoptera littoralis have eight types of haemocytes prohaemocytes, phagocytic cells (palsmatocytes, spindle cells and gran-ular cells), oenocytoids, adipohaemocytes, spherulocytes and cystocy‌tes. Biometric measurements of different haemocytes and the ratios between nuclei and cells were determined in unparasitized and parasi‌tized S.littoralis larvae and after treatments with LC1 0 level of each of delfin and baythroid. Parasitism (by Microplitis rufiyentris) resulted in the appearance of abnormalities in all types of haemocytes, as irregulari‌ty and elongation of cell wall with twisting at ends of spindle cells. The cytoplasm of cells was badly and faintly stained. The cystocytes disap-peared from the haemolymph of larvae at I and 3 days after parasitism. When treated with LC10 level of each delfin, the cells and nuclei were affected by the moving to the cell wall, so losing its central posi‌tion. Also, the cell walls became irregular in shapes. The cystocytes dis‌appeared from larval haemolymph at 5 days old S.Iitoralis larvae, but dis‌appeared from parasitized ones at 1, 3, 5 and 7 days after parasitism. Morphological changes were observed in different haernocytes of different S.littoralis larval ages treatment with LC10 level of baythroid. Effect of baythroid on the haemolcytes was more obvious than those of delfin. The cells became irregular in shape, the nucleus moved towards cell wall, losing its centraal position and cellular vacuolization was ob‌served. Cystocytes disappeared from the haemolymph of 7 days old S.littoralis larvae, but disappeared at 1, 3, 5 and 7 days after parasitism.