Biological, biochemical and histological effects of spinosad, Bacillus thuringiensis var. kurstaki and cypermethrin on the Cotton leafworm, Spodoptera littoralis (Boisd.).

Abstract

The insecticidal, biological, biochemical and histological effects of bioagent spinosad, Diple 2x (Bacillus thuringiensis var kurstaki) and one pyrethroid compound (cypermethrin) were evaluated on 4th instar larvae of Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae). Based on the LC50 values Cypermethrin is the more toxic to S. littoralis than that of the two other compounds. Female longevity, fecundity and fertility were significantly reduced at all treatments compared to control. Furthermore, different levels of significant changes in the total protein, carbohydrate contents, phosphatasis activity and carbohydrasis, were recorded. Moreover, different abnormal histological structures of ovary were noticed.