Entomopathogenic fungi against the red palm weevil: Lab and field evidence

Abstract

Palms are threatened by a major pest, the red palm weevil, Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae). The damage caused by its infestation is costly, often resulting in the removal of affected trees and the need for additional treatments to halt the pest's spread. The larvae's development and feeding activities within the trunk cause extensive damage to the trees. However, the lack of early infestation signs worsens the spread of the attack. While chemical treatments are effective, they pose issues such as pest resistance, worker health risks, and environmental concerns. Entomopathogenic fungi (EPF) such as Beauveria bassiana, Metarhizium anisopliae, Isaria fumosorosea, and Lecanicillium lecanii, are a promising alternative for managing RPW infestations. This literature review delves into the biology, ecology, and infection process of EPF and RPW, as well as the factors influencing the effectiveness of EPF against R. ferrugineus throughout its life cycle. The review also assesses the various EPF application and delivery methods along with the challenges and risks associated with their field use. It summarizes the results of various studies that tested the ability of EPF to control RPW in the laboratory and in the field, comparing the efficacy of different species and strains of EPF. The review concludes that EPF can significantly reduce RPW populations and damage, particularly when used in conjunction with other control methods like pheromone traps, insecticides, and sanitation. However, it also underscores the need for additional research and development to optimize the use of EPF for R. ferrugineus management and ensure their safety and sustainability.