Chronic sublethal exposure to chlorantraniliprole inhibits growth and development by disrupting the sugar and fatty acid metabolism in Spodoptera frugiperda

Abstract

Chlorantraniliprole is extensively utilized for managing lepidopteran pests, such as Spodoptera frugiperda. However, its long-lasting residual effects and extended half-life result in prolonged exposure of target insects to low dose insecticide, leading to sublethal effects. This study investigates the sublethal effects of chlorantraniliprole on the growth and development, reproductive capacity, population parameters, nutritional indicators, and sugar-lipid metabolism in S. frugiperda. The results demonstrated that sustained exposure to sublethal concentrations not only prolongs larval and pupal stages but also significantly decreases weights at each developmental phase, lowers pupation rates and markedly impairs ovarian development. Furthermore, exposure to sublethal chlorantraniliprole significantly increased approximate digestibility (AD) but decreased efficiency of conversion of digested food (ECD), efficiency of conversion of ingested food (ECI), and relative growth rate (RGR) in F₀, leading to nutrient deficiencies required for proper growth, development, and metabolic detoxification, with a substantial depletion of stored energy reserves. Importantly, the finding revealed a significant decrease in energy storage compounds (glycogen, trehalose, and triglycerides) in the treated insects, accompanied by changes in enzymes and genes associated with sugar-lipid metabolism. Moreover, age-stage two-sex life table analysis revealed significant transgenerational impacts, hindering the population growth of the F₁ generation. Overall, these findings underscore the importance of recognizing sublethal effects when designing pest management strategies, demonstrating the efficacy of chlorantraniliprole while also highlighting the necessity of considering its potential long-term ecological consequences.

Keywords: Chlorantraniliprole; Nutritional indicators; Spodoptera frugiperda; Sublethal effect; Sugar and lipid metabolism.