مشخصات پژوهش

The current study was designed to determine the toxicity of pyriproxyfen, lufenuron and tebufenozide on the 3rd instar larvae of Helicoverpa armigera. The insecticides were incorporated into the diet and exposed to the larvae then three concentrations of LC30, LC50 and LC70 of pyriproxyfen, tebufenozide and lufenuron were tested to assay larval weight, amount of fat and protein as well as the activity of three digestive enzymes. Bioassay revealed the LC50 values of 3.7, 12.49 and 1.56 mg ai/L, respectively. Increased concentrations of the insecticides significantly decreased the larval weight and the amount of fat and protein compared to control as the least value was recorded on LC70 concentration of lufenuron. The LC50 concentrations of tebufenozide and lufenuron caused the least activity of α-amylase, lipase and protease in the treated H. armigera larvae compared to control. The results demonstrated that not only pyriproxyfen, tebufenozide and lufenuron have proper entomotoxicity against H. armigera larvae but also they significantly affect some physiological traits in both sublethal and lethal concentrations.