Antipredator behavior of Tetranychus urticae Koch (Trombidiformes: Tetranychidae) on melon

Predation risk may influence prey behaviour, driving antipredator strategies such as behavioural changes, refuge use, and shifts in oviposition. Leaf trichomes may provide refuges for herbivores, acting as barriers to predators. This study evaluated whether Tetranychus urticae Koch uses melon leaf trichomes as an antipredator strategy, whether this response differs under predation risk from the specialist Neoseiulus idaeus Denmark & Muma and the generalist Neoseiulus barkeri Hughes, and whether trichomes affect predator performance. To assess oviposition behaviour, T. urticae females were exposed to four predation-risk levels: Control (no predator), High Risk (direct exposure), Medium Risk (indirect cues), and Low Risk (simulated predation by crushed eggs). Antipredator responses were assessed based on daily oviposition rate and oviposition site (trichomes, glabrous areas, and web). Predator performance was evaluated based on prey encounter time and egg consumption on melon and jack bean leaves, which differed in trichome density. Under predation risk, T. urticae reduced oviposition, particularly in response to the specialist predator. Oviposition shifted to webbed areas rather than trichomes. High trichome density increased prey encounter time for N. idaeus and reduced egg consumption by both predators. Overall, T. urticae primarily relies on webbed oviposition as antipredator strategy, while trichomes reduce predator efficiency.