Untargeted metabolomics of Spodoptera litura (Lepidoptera: Noctuidae) gut reveals physiological difference among eight diets

Abstract

Spodoptera litura (Fabricius) is a major pest of tobacco and other hosts. Mass-rearing of S. litura is essential for implementing various control strategies. We evaluated the effects of eight different diets on the growth and development of S. litura larvae, followed by untargeted metabolomics analysis to assess physiological and metabolic differences in their gut due to diet variations. Significant differences were observed in the development duration and weight of S. litura larvae across different diets. When reaching the fourth instar, larvae fed with corn leaf powder (development periods: 2.13 ± 0.12 days; weights: 4.68 ± 0.09 g) and Chenopodium album leaf powder (2.05 ± 0.10 days; 4.69 ± 0.09 g) had shorter development periods and greater weights compared to those fed with tobacco (2.56 ± 0.10 days; 4.52 ± 0.12 g), C. album (2.49 ± 0.12 days; 4.53 ± 0.11 g), and other groups. Moreover, metabolites from natural diets negatively impacted larval growth, with the lower quantities and expression levels in significantly enriched pathways than those in corn leaf powder and C. album leaf powder. Among the natural diets, C. album outperformed both tobacco and corn. Artificial diet with corn leaf powder is suitable for mass-rearing of S. litura. This study serves as a reference for optimizing the artificial diet of S. litura.