Nutritional Resources Regulate the Reproduction or Migration of Spodoptera frugiperda through Juvenile Hormones and...

Spodoptera frugiperda is a significant agricultural pest that migrates annually based on the growth stages of its host plants. However, the role of host plant growth stages in the residency or migration of S. frugiperda remains unclear. We allowed S. frugiperda to feed on maize leaves and seeds, and results showed that maize seeds had higher amino acids, carbohydrates, and triglyceride (TG). S. frugiperda that fed on seeds had longer adult stages; larger wings; higher TG, juvenile hormone II (JH II), and JH III; and more developed flight muscles, indicating tendencies toward migration. Interestingly, maize leaves were richer in sterols. S. frugiperda that fed on leaves exhibited longer larval stages, higher 20-hydroxyecdysone (20E) and JH I, faster egg maturation, and earlier oviposition, suggesting tendencies toward residency. These findings suggest that the nutritional composition of host plants influences S. frugiperda for migration or reproduction, offering new insights into its invasion and establishment patterns.