Studies on the morphology and histology of the ovary of red palm weevil female irradiated with gamma rays

Abstract

The present study involves red palm weevil adults Rhynchophorus ferrugineus (Oliver) (Coleoptera: Curculionidae) irradiated with 5, 10 or 15 Gy of gamma radiation. The biological effects of gamma irradiation on the F 1 adult females, descendant of irradiated parental male pupae, were studied. The percentage egg hatch decreased significantly, as the dose increased, compared with the untreated control. The effect of gamma irradiation on the morphology of the ovaries showed a remarkable effect on size, shape and measurement of the paired ovaries. Additionally, histological studies showed some damages by irradiation of the oocytes maturation, which increased with increasing dose. These symptoms were elongation of the terminal filament, rupture, separation, or shrinkage of external sheath and follicular epithelium, degenerated or absent of nurse cells, and ruptured oocytes at 15 Gy. Vacuolation appeared in different degrees inside the oocytes and the nurse cells were absent in some areas. The damage in the oocytes was more severe as the dose was increased. The follicular epithelium was thin, oocytes clumped together throughout the ovariole causing some oocytes become abnormal or rectangular in shape.