Zinc sulphate as a growth disruptore against the cotton leafworm Spodoptera littoralis with reference to its effect on larval endocrine glands

Zinc sulfate (ZnSO4 7H2O) was toxicologically,biologically,and physiologically evaluated as insect development inhibitor and endocrine disruptors against the fourth instar larvae of the cotton leaf worm,S.littoralis . Zinc sulfate significantly increased both larval and pupal duration and decreased the pupal weight and percentages of pupation as compared to control. The fecundity and fertility of female adults resulting from treated larvae in all mated combinations were remarkably decreased ,as compared to control untreated one. The data also showed that the females were more sensitive to Znic sulfate than the males.Ultrastructure changes of the endocrine glands of larvae are discussed. Zinc sulfate may be used as growth disruptor for S.littoralis between the other control methods for S.littoralis management.