Effects of hexaflumuron, lufenuron and chlorfluazuron on certain biological and physiological parameters of Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae)

Helicoverpa armigera (Hiibner) (Lepidoptera: Noctuidae) is one of the most economically devastating pests of agricultural crops around the world. In this study, the effects of hexaflumuron, lufenuron and chlorfluazuron were evaluated on some biological and physiological parameters of H. armigera larvae. Effects of the insecticides were assessed by adding different concentrations into the larval artificial diet. Dose-response bioassay showed LC 50 values of 6.16, 61.31 and 31.75 mg ai/1 for hexaflumuron, lufenuron and chlorfluazuron, respectively. Subsequently, sublethal effects of hexaflumuron, lufenuron and chlorfluazuron were assessed using LC io concentration to find their possible effects on the biological and physiological parameters of H. armigera larvae. The results showed significant changes in biological parameters, where the mean larval and pupal weights significantly decreased following treatment, while their developmental time significantly increased compared to the control. Meanwhile, the longevity of adult males and females, number of laid eggs per female, and rate of egg hatch were significantly reduced due to the insecticide treatments. The activities of alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transferase, acid- and alkaline phosphatases, lactate dehydrogenase, glutathione S-transferase were increased following the treatments. Sublethal exposure of the insecticides on larvae led to lower amounts of glycogen, triglyceride and protein compared to the control.