Virulence of fungal spores and silver nano-particles from entomopathogenic fungi on the red palm weevil, Rhynchophorus ferrugineus Olivier (Coleoptera: Curculionidae)

The red palm weevil, Rhynchophorus ferrugineus Olivier (Coleoptera: Curculionidae), is one of the most severe pests of date palms. The study aimed to evaluate the virulence of fungal spores and silver Nano-particles from entomopathogenic fungi (EPF) on R. ferrugineus under laboratory conditions. Concentrations of the fungal spores and the silver Nano-particles were prepared from Metarhizium anisopliae, Beauveria bassiana, and Verticillium lecanii. The results showed that the 3 EPF achieved 70–90% mortality rates within 7 days in egg stage. M. anisopliae and B. bassiana were the most effective ones. The isolate V. lecanii was tested on eggs, larvae, and adults. Spores of M. anisopliae increased eggs’ mortality and reduced their hatchability. The egg mortality rate was 80% higher than the control. Seventy-percent adult mortality rate was achieved in 7 days, when treated with M. anisopliae, 60% with B. bassiana, and 53% with V. lecanii. M. anisopliae was more effective on R. ferrugineus than B. bassiana.