Harnessing biological control agents to mitigate red palm weevil infestations

Abstract

The red palm weevil (Rhynchophorus ferrugineus) is the primary insect pest causing damage to date palms (Phoenix dactylifera L.) in production areas. In the pursuit of safe control methods, this study aims to evaluate the efficacy of the entomopathogenic fungi Trichoderma virens and Metarhizium anisopliae against red palm weevil larvae and adults under laboratory conditions, as well as their impact on palm recovery in field conditions. The results indicated that T. virens achieved the highest mortality rates in both larvae and adults. Both fungi also compromise the weevil’s defense mechanisms by altering its chemical composition, including total lipid, protein, and carbohydrate levels, in addition to the activities of superoxide dismutase and glutathione peroxidase. Additionally, T. virens demonstrated superior palm recovery compared to M. anisopliae and untreated control trees in the field, facilitating the recovery of approximately 70% of the treated palm trees under experimental conditions. These findings suggest T. virens as a promising biocontrol agent for managing red palm weevil infestations and enhancing palm health.