CONTROL OF RED RING DISEASE BY MASS TRAPPING OF RHYNCHOPHORUS PALMARUM (COLEOPTERA: CURCULIONIDAE)

Abstract

Rhynchophorus palmarum (L), the American palm weevil, is an important pest of several palm species in tropical America as a vector of the red ring nematode Bursaphelenchus cocophilus Cobb. Bimonthly inspections coupled with elimination of red ring diseased (RRD) oil palms (Elaeis guineensis Jacq.) failed to reduce infection rates of oil palms in two commercial plantations in Costa Rica. Addition of pheromone-based trapping of R. palmarum using trap densities of less than one trap per five hectares lowered RRD in both plantations by over 80% in one year. Continued removal of RRD infected palms and trapping maintained RRD at very low levels over several years. No matter what the initial RRD infection level, trap density or capture rate, areas with high and areas with low RRD infection levels declined to the same low RRD infection level after one year of trapping. An efficient strategy for management of RRD in oil palm is based on an integrated approach where RRD and other diseased (e.g., spear rot) palms are promptly eliminated or properly treated and pheromone-baited traps are used to reduce populations of R. palmarum. These strategies are complimented by removal of weevil-infested palms after wind and lightning damage and periodic removal of palms (e.g., coconut palms) in surrounding areas that serve as hosts for R. palmarum.