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 .