Abstract
The red palm weevil, Rhynchophorus ferrugineus (Olivier) (RPW) is a destructive insect pest of palm trees, destroying thousands of date palm trees in Kingdom of Saudi Arabia (KSA) and other countries. Radio telemetry has provided beneficial knowledge on the movements, the habitat preference, and reproductive behaviors of numerous species of animals. In this study, we tracked the movements and habitat preferences of RPW in date palm orchards in KSA using radio telemetry with and without the use of pheromone traps. This study is the first to track individual adult RPW using radio telemetry in production date palm orchards. Small radio transmitters (LB-2X, HOLOHIL) were glued on wild-caught adults and released in date palm orchard in late April and early May 2019. Our results indicated that wild-caught adult RPW with attached dummy transmitters were able to fly normally, whereas laboratory-reared adults were unable to fly successfully with attached transmitters. The flight behavior of the RPW adults was influenced by pheromone traps. The average flight of the RPW was 69.1 m (7.7-213 m) in the presence of pheromone traps and only 24.4 m (10-90 m) without pheromone traps. The mean distances females and males covered were 95.80 m and 42.40 m in the presence of pheromone traps and 32.47 m, 16.30 m in the absence of pheromone traps, respectively. The percentages of tagged adults that dispersed more than 50 m were 50% and 8.3% in the presence and absence of pheromone traps, respectively. Time required for taking-off from the release point was 5-20 min and 0.5-6 h in the presence and absence of pheromone traps, respectively. The aggregation rate was 33.3% and 75.0%, in the presence and absence of pheromone traps, respectively. Only a single flight was taken by each adult in the presence or absence of pheromone traps. Adults showed high preference in selecting habitats. RPW adults were attracted to infested or previously infested male palm trees, surface water of drip irrigation systems, and pheromone traps. In conclusion, radio telemetry appears to be a suitable technique to track RPW in date palm orchards when wild-caught adults are used.