Abstract
The widespread as well as serious damage produced by the red palm weevil (RPW), Rhynchophorus ferrugineus Olivier, have forced emphasis of various research teams on finding appropriate methods for managing and controlling it. A huge fund was given for managing and controlling RPW in several countries. In this study, the potential toxicity of oxamyl to RPW was evaluated under both laboratory and field conditions. In the laboratory, oxamyl had significant effects on the mortality of RPW. After exposure to direct spray of oxamyl, adult mortality was 62, 82 and 100% whereas larvae mortality was 72, 77 and 100% after 1, 24 and 48 h, respectively. Alive adult and larvae were completely paralyzed after 24 hours. There was significant difference between 2 treatments, 1 and 24 h, in both adult and larvae. The mortality of both adult and larvae was 100% after 48 hours of exposure to oxamyl. In the field, however, Oxamyl was applied in two different applications. A foliar application by spraying and watering application by adding the to the irrigation water. After 2 days of applications, daily monitoring was conducted for 10 days to record any dead or paralyzed adults and/or larvae. Dead and paralyzed adults or larvae were found particularly in foliar application compared with the control. Furthermore, females egg-laying defect with serious reduction in their movement was recorded especially in foliar application. Egg hatching was not affected with minimal activity in both applications compared with control. Moreover, no mortality of adults emerging from pupae was recorded and they only showed detectable reduction on their movement in both field treatments. Finally, this study would recommend the use of oxamyl in managing and controlling the infestation of RPW.