Female light capture is shaped by juvenile hormone-mediated post-mating behavior in the diamondback moth.

BACKGROUND Post-mating behavioral changes are crucial for optimizing female reproductive success in insects, frequently resulting in shifts in both physiology and behavior. In moths, light traps typically capture more mated females than unmated ones; however, the mechanisms driving this discrepancy remain unclear. RESULTS In this study, we examined how mating status influences female light capture in the diamondback moth (DBM; Plutella xylostella). Both field and laboratory experiments consistently showed that mated females had higher light capture rates, especially during the first 2 h of the scotophase. Behavioral assays indicated that mating increased locomotor activity, including total movement distance and speed. Transcriptomic analyses of female heads revealed significant upregulation of juvenile hormone (JH)-inducible genes-particularly juvenile hormone esterase (JHE)-in both mated and light-trapped females. Applying the JH analog methoprene to unmated females increased their locomotor activity and light capture rates, supporting a role for JH signaling in mediating this behavioral change. CONCLUSION These findings demonstrate that post-mating hormonal changes enhance female mobility, which subsequently increases their capture in light traps, establishing a mechanistic link between reproductive status and behavior. Our research highlights how hormonal regulation influences ecologically significant behaviors and may contribute to the development of strategies for monitoring and controlling nocturnal insect pests. © 2025 Society of Chemical Industry.