4-Methyl-5-nonanone is an aggregation pheromone component isolated from the red palm weevil (Rhynchophorus ferrugineus), working synergistically with 4-methyl-5-nonanol (ferrugineol) as their primary communication signal . When combined with 4-methyl-5-nonanol and ethyl acetate in field trials, this compound forms a multi-component attractant that efficiently traps adult weevils. For instance, in Java, Indonesia, traps baited with 4-Methyl-5-nonanone captured 15-20 adults per hectare weekly, achieving a 40% higher monitoring sensitivity compared to single-component traps .