Efficiency of optimal pheromone trap density in management of red palm weevil, Rhynchophorus ferrugineus Olivier

The red palm weevil (RPW), Rhynchophorus ferrugineus Olivier is an invasive, hidden pest of date palms causing significant economic losses in Middle East. Mass trapping of weevils with synthetic male aggregation pheromone and food baited traps has been an important component of Integrated Pest Management (IPM) program against RPW. As the viability of pheromone trapping system depends on the optimum trapping density, field experiments were conducted in two locations of Eastern Province of Saudi Arabia. The efficiency of four pheromone trap densities viz., 1, 2, 4 and 8 traps/4 ha, were evaluated using the Standard Saudi Trap. In Al Hassa experiment, the treatment with 1 trap / 4ha captured an average 10.0 weevils as compared to 61.5 weevils in 8 traps / 4 ha, while at Al Qatif experiment an average of 5.0 and 49.8 weevils were captured in 1 trap and 8 traps / 4 ha respectively in 10 weeks indicating the superiority of high density trapping. Although RPW adults are strong fliers, these experiments showed that more traps per unit are necessary to capture the resident adults in a shorter period of time. Hence, our studies provide information for optimizing trap density for mass trapping program. Key words: Red palm weevil, Rhynchophorus ferrugineus, pheromone, trap density, date palm.