(3Z,6Z,9Z)-3,6,9-Tricosatriene is a key component of the female sex pheromone in the tobacco cutworm (Spodoptera litura), isolated from the glandular extracts of female moths. When blended with minor components such as Z9,E12-tetradecenyl acetate (Z9,E12-14:OAc) at optimized ratios (e.g., 7:3), it forms a highly effective multi-component lure for monitoring and controlling S. litura in vegetable and sugarcane fields. Field trials demonstrate that each pheromone trap captures 20-40 male moths per night, increasing monitoring accuracy by over 40% compared to traditional light traps while minimizing non-target insect bycatch.