Response of Life Parameters and Nutritional Physiology of Spodoptera frugiperda (J.E. Smith) to Sublethal Concentrations of Chlorantraniliprole

Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), known as fall armyworm (FAW), poses a significant economic threat to maize and other agricultural crops in Egypt and worldwide. Research on sub-lethal effects of new compounds on FAW is important for controlling resistance of this pest to many conventional insecticides. Sub-lethal effects of chlorantraniliprole were evaluated through exposure of third-instar larvae to LC10, and LC25 values into an artificial diet. FAW showed high susceptibility to chlorantraniliprole with a low LC50 value (0.25 μg.g-¹ at 72 h). The development time of the larval and pupal stages as well as total pre-oviposition period were significantly prolonged after exposure to chlorantraniliprole at sublethal concentrations (LC10 and LC25), compared to the control treatments. Relative to the control treatment, chlorantraniliprole at sub-lethal concentrations significantly reduced the adult emergence ratio and egg hatching rate while increasing the pre-oviposition period. The net reproductive rate (R0), intrinsic rate of increase (rm), and gross reproduction rate (GRR) at LC10, LC25 concentrations were significantly lower than that of the control. Furthermore, compared to those treated with the control, FAW larvae treated with low concentrations of chlorantraniliprole decreased food utilization and nutrient content (protein, lipid, and carbohydrate). This study provides information to evaluate the rational application of chlorantraniliprole for effective control of this pest.