Studying the effectiveness of Jatropha carcus L. Extract as a repellent, antifeedant, and toxic substance against red palm weevil (Rhynchophorus Ferrugineus) adult insects in Saudi Arabia

Red palm weevil (RPW), Rhynchophorus ferrugineus, is a highly harmful pest that causes severe damage to date palm trees. The detrimental influence of RPW on date palm trees cannot be ignored and must be addressed. Chemical insecticides are available for controlling RPW; however, the insect population has become resistant to these chemicals, leading to damage and spread to new areas. The present investigation examined the impacts of physic nut (Jatropha curcas L.) seeds essential oils (PNEO) on laboratory-reared RPWs adult insects reared in a controlled laboratory environment. The insecticidal, repellent, and antifeedant potentials of different doses (10, 20, 30, 40, 50%) of PNEO were tested against RPW. The insecticidal activity of J. curcas seeds oil extracts was assessed using topical application and feeding methods. RPW showed a high mortality rate when J. curcas seeds oil was applied topically after 24 h (P < 0.05). The mortality (%) of insects was 8, 76, 92, 96, and 100 for 10 %, 20 %, 30 %, 40 %, and 50 % concentrations, respectively. The LC50 and LC90 were 16.50 %, and 28.14 %, respectively. Results from the feeding method demonstrated a significant increase in mortality with a 100 % mortality rate at higher concentrations of PNEO compared to 10 and 20 % concentrations (P < 0.0001). The LC50 and LC90 were 24.42 % and 31.30 %, respectively. There was no significant decrease in food consumption and the antifeedant index when 10 % and 20 % of J. curcas seeds oil were used on the 3rd and 6th day after application. All J. curcas oil concentrations showed a repellent effect significantly higher than the controls (P < 0.05). J. curcas seeds oil has shown potential insecticidal and repellent effects against RPW, and it could provide an eco-friendly tool for RPW pest management.