Biochemical effects of some insect growth regulators and bioinsecticides against cotton leafworm, Spodoptera littoralis (Boisd.)(Lepidoptera Noctuidae).

Abstract

The current work was carried out to evaluate the biochemical effects of LC50 of four compounds; emamectin and spinetoram as bioinsecticides, hexaflumuron and teflubenzuron as Insect growth regulators (IGR’s) against the 4th instar larvae of Spodoptera littoralis to determine the effects of these compounds on total carbohydrates, proteins, lipids, acetylcholinesterase, chitinase, phenoloxidase, carbohydrates hydrolyzing enzymes, non-specific esterases, phosphatases and transaminase enzymes.The obtained results indicated that total proteins and lipids content were significantly decreased with all tested insecticides, except slightly increase in total protein with spinetoram, in contrast, all tested insecticides led to an increase in total carbohydrates. The tested insecticides significantly increased the invertase activity except emamectin decreased the enzyme activity. A significant decrease in the activity of trehalase and amylase activity was induced by the tested insecticides, except with emamectin and teflubenzuron in case of amylase. The tested insecticides significantly decreased the activity of acid (AcP) and alkaline (AlP) phosphates. It is clearly noticed that teflubenzuron and spinetoram significantly increased alpha esterases in contrast, decreased with hexaflumuron and emamectin. A highly significant decreased in beta esterases was induced by teflubenzuron and hexaflumuron and increased with spinetoram and emamectin. All tested insecticides induced a significant inhibitory effect on aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activity except with teflubenzuron.Acelylcolinesterase (AchE) activity significantly increased with emamectin and teflubenzuron while decreased with hexaflumuron and spinetoram. Phenoloxidase and Chitinase activity significantly increased with all tested insecticides.