How far can Red Palm Weevil (Rhynchophorus ferrugineus) fly? An examination of field and laboratory flight activity in Al Ahsaa, Saudi Arabia

Red Palm Weevil (Rhynchophorus ferrugineus) is one of the world’s most destructive palm pests yet very little is known about its natural dispersal and flight activity. This pest has had a prolific invasion history due to worldwide human movement of palms but it also has the ability to invade new areas on its own.  Anecdotal literature reports indicate that RPW may be able to fly 3-5km but no robust testing has been performed to confirm the validity of this suggested flight distance.  While RPW research has been ongoing for many years utilizing this assumption, the lack reliable data to confirm flight dispersal capabilities prevents the true effective development of quarantine protocols or establishment of applicable farming practices within an infected region. In an attempt to better understand RPW dispersal potential, we conducted 2 studies in Al Ahsaa, Saudi Arabia over 3 seasons in 2011-2012 (winter, spring and summer). The studies were:  1) Capture-Mark-Release- Recapture studies in an open desert field environment utilizing baited pheromone traps and 2) flight mill studies conducted in a laboratory setting.  Weevils for this experiment were obtained from Ministry of Agriculture traps. Weevils were reconditioned on sugarcane for 1-2 weeks before being utilized in either experiment.  For field releases, only male RPW were used to eliminate establishment of populations of this pest in new environments. Flight mill studies utilized both sexes. We determined that there are differences in flight activity and environmental pressures for these weevils over the various seasons that could affect how quarantine and farming practices could be conducted for regions in which this weevil is present. This information, will allow other researchers, government policy making officials and farmers to develop new protocols to incorporate the true flight potential of RPW into management programs.