Optimizing components of pheromone-baited trap for the management of red palm weevil, Rhynchophorus ferrugineus (Coleoptera: Curculionidae) in date palm agro-ecosystem

The red palm weevil (RPW), Rhynchophorus ferrugineus (Olivier), is managed in date palm groves, inter alia, with food-baited pheromone traps. Laboratory and field trials were carried out to enhance the RPW pheromone- trapping efficiency. Sensitive olfactometer assays revealed that newly emerged male and female RPW adults (virgins) were highly attracted to the aggregation pheromone (ferrugineol), which decreased with age and mating. Field and laboratory studies on the efficacy of four commercial lures revealed that these commercial lures were equally effective in attracting RPW adults. Furthermore, addition of two yeast species, namely Saccharomyces cerevisiae and Candida utilis (2 g/trap each), in the food bait (dates) in RPW pheromone traps did not significantly enhance weevil captures. Only around 35% of the test insects (male and females) were attracted to the pheromone in the olfactometer assays, indicating that pheromone trapping alone cannot be relied upon to control RPW, but should be deployed with other management tactics.