Exophthalmus weevil

The genus Exophthalmus belongs to the order Coleoptera and the family Curculionidae. These weevils are notable pests in tropical and subtropical regions, primarily affecting a wide variety of fruit trees and perennial industrial crops.

The host range of Exophthalmus includes essential agricultural species such as citrus, coffee, cocoa, and various ornamental trees. Adults are known to feed on foliage, while the larvae inhabit the soil, where they consume the roots of the host plant, creating a dual-threat mechanism for the trees.

The life cycle begins with eggs deposited on the leaf surface, often protected by the leaves being glued together. Upon hatching, the larvae drop to the ground and burrow into the rhizosphere. This soil-dwelling behavior makes them difficult to target during the most destructive period of their growth.

Damage symptoms caused by adults include jagged leaf margins and skeletonized foliage. Larval feeding on roots leads to stunted growth, nutrient deficiency symptoms, and reduced vigor of the tree. In severe infestations, the cumulative damage can lead to tree death, especially in young nursery stocks.

Effective management requires an integrated pest management (IPM) strategy. Key methods include the application of contact and systemic insecticides to foliage to control adults and the use of soil drenching with entomopathogenic nematodes or fungi to address the larval stage. Cultural practices, such as maintaining soil health and removing debris, are also vital for reducing breeding habitats.