Effects of Trap Locations, Pheromone Source, and Temperature on Red Palm Weevil Surveillance (Coleoptera: Dryophthoridae)

Abstract

Pheromone traps play a crucial role in the integrated pest management of the red palm weevil, Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae). The objective of this study was to increase the effectiveness of pheromone traps by evaluating the effects of location, temperature, degree of palm fruit fermentation, and pheromone lure source on red palm weevil capture rates. Traps baited with either Ferrolure or Rhylure were positioned in 3 rows and checked twice per wk for 12 wk starting 20 Apr 2019. Overall weekly capture rate per trap varied from 1.25 to 9.00. Those traps that were placed in the shade near infested date palm trees in areas of relatively high soil moisture captured more red palm weevil (9 adults per trap per wk) than traps exposed to direct sunlight (1.25 adults per trap per wk). Additionally, traps placed at the field edge captured more adults than those in the middle of the field. Capture rates were highly negatively correlated with temperature. Ferrolure traps captured significantly more red palm weevils than Rhylure traps. The sex ratio of captured weevils in all traps was female-biased. Results obtained from Y-tube olfactometer assays indicated that the response of red palm weevil adults to 5- and 8 d old fermented date fruits were relatively high (86.7–100%). In kairomone field tests more red palm weevil adults were attracted to traps with 8 d fermented date fruits compared with 5 d old. Our results indicated that placing traps containing Ferrolure, water, and kairomones in red palm weevil preferred sites near the edges of the orchard in moderate air temperatures (22–33 °C) increased the efficacy of pheromone traps.