Sublethal deltamethrin and chlorantraniliprole exposure induces detoxification and oxidative stress in Leptinotarsa decemlineata Say. (Coleoptera: Chrysomelidae) biochemical implications

Abstract This study investigated the biochemical impacts of sublethal concentrations of deltamethrin and chlorantraniliprole on Leptinotarsa decemlineata , a key pest of potato crops. The primary objective was to elucidate how these compounds influence detoxification enzymes, oxidative stress responses, and digestive/metabolic functions. Experimental treatments included LC₃₀, LC₄₀, and LC₅₀ concentrations, and the activities of catalase (CAT), glutathione S-transferase (GST), α-amylase, lipase, as well as total protein content, were quantified. The findings demonstrated that both insecticides induced a dose-dependent increase in CAT and GST activities, indicating the generation of oxidative stress and the subsequent activation of antioxidant defense mechanisms. In contrast, α-amylase and lipase activities, along with total protein levels, were significantly reduced, suggesting that digestive efficiency and energy metabolism were adversely affected under insecticide exposure. Comparative evaluation revealed that deltamethrin produced more consistent and predictive dose–response relationships across most parameters, with higher explanatory power. Conversely, chlorantraniliprole elicited sharper yet more variable responses depending on the measured endpoint. Overall, sublethal insecticide exposure was shown to trigger enhanced oxidative stress while simultaneously imposing metabolic constraints, reflecting a trade-off within the defense–energy balance framework. These results underscore the importance of integrating multiple biochemical biomarkers when assessing the sublethal effects of insecticides.