Integrated biological characteristics, enzyme activity, and gene expression profile analyses of Spodoptera frugiperda larvae in response to caffeic acid exposure

CA inhibited the growth and altered the development of S. frugiperda. • CA exposures altered detoxifying and digestive enzyme activities of S. frugiperda. • DEGs enriched in pathways of Toll/Imd signaling, lysosome, and peroxisome. • DEGs also enriched in detoxification, digestion, hormone synthesis, etc. The fall armyworm, Spodoptera frugiperda , has become a prominent global agricultural pest, threatening food production significantly. Caffeic acid (CA) is a phytochemical demonstrating considerable biological effectiveness against several pests. Nonetheless, the impact of this chemical on S. frugiperda is currently unascertained. This study assessed the growth inhibitory effects of CA on S. frugiperda larvae. The impact of 0.50 and 2.0 mg/g CA treatments on the growth and development of S. frugiperda was further examined. The administration of 0.50 and 2.0 mg/g CA could modify the detoxifying and digesting enzyme activity in the larvae. A total of 791 and 1704 differentially expressed genes (DEGs) were identified in the groups administered 0.50 and 2.0 mg/g CA treatments, respectively, in comparison to the control group. The differentially expressed genes were significantly enriched in immune-related pathways, including Toll/Imd signaling, lysosome, and peroxisome. In addition, the DEGs involved in detoxification, hormone synthesis, nutrient digestion and absorption, and fatty acid metabolism were also analyzed. Our findings suggest that CA may regulate the expression of these DEGs, hence influencing process functions and ultimately leading to growth inhibition in Spodoptera frugiperda larvae, underscoring CA's potential for pest management.