Toxicological and Biochemical Studies on the Effect of Lufenuron, a Chitin Synthesis Inhibitor Alone or Combined with Gamma Radiation Against Spodoptera littoralis Larvae1

Abstract

This study aimed to investigate the combined effect of lufenuron and gamma radiation against the cotton leaf worm. Full-grown pupae were irradiated with a substerilizing dose 100Gy, and the 4th instar larvae of the F1 were used in the experiments. The results revealed that the percent mortality was time- and concentration-dependent, and the F1 larvae were more susceptible to lufenuron than the normal larvae. The enzymatic analysis of phenoloxidase and acetylcholinesterase activities showed that the F1 larvae treated with LC50 of lufenuron exhibited the highest activity when compared to larvae treated with LC50 of lufenuron or F1 larvae. We conclude that a combination of gamma radiation and lufenuron could be an excellent integrated control program for Spodoptera littoralis.