Trait responses, nonconsumptive effects, and the physiological basis of Helicoverpa armigera to bat predation risk

Predation reduces the population density of prey, affecting its fitness and population dynamics. Few studies have connected trait changes with fitness consequences in prey and the molecular basis and metabolic mechanisms of such changes in bat-insect systems. This study focuses on the responses of Helicoverpa armigera to different predation risks, focusing on echolocating bats and their calls. Substantial modifications were observed in the nocturnal and diurnal activities of H. armigera under predation risk, with enhanced evasion behaviors. Accelerated development and decreased fitness were observed under predation risks. Transcriptomic and metabolomic analyses indicated that exposure to bats induced the upregulation of amino acid metabolism- and antioxidant pathway-related genes, reflecting shifts in resource utilization in response to oxidative stress. Exposure to bat predation risks enhanced the activity of DNA damage repair pathways and suppressed energy metabolism, contributing to the observed trait changes and fitness decreases. The current results underscore the complex adaptive strategies that prey species evolve in response to predation risk, enhancing our understanding of the predator–prey dynamic and offering valuable insights for innovative and ecologically informed pest management strategies. Helicoverpa armigera shows adaptive trait changes under bat predation risk, with increased evasion, accelerated development, and fitness decreases. Molecular analyses reveal shifts in metabolism and stress response pathways linked to these changes.