Citrus root weevil

Systematic position. This species belongs to the order Coleoptera and the family Curculionidae. Members of the genus Exophthalmus are recognized as significant agricultural pests in tropical and subtropical regions, often causing substantial economic losses in citrus plantations.

Host plants. The primary hosts are citrus species, including sweet orange, lemon, lime, and grapefruit. Due to its polyphagous nature, it may also infest various native woody plants in proximity to orchards, making management particularly challenging in diverse agroecosystems.

Biology and lifecycle. The lifecycle consists of egg, larval, pupal, and adult stages. Adults are foliage feeders, primarily active during the night. Females typically deposit eggs in protected areas, often gluing leaves together to hide them. Upon hatching, the larvae drop to the ground and burrow into the soil to feed on roots.

Damage and pest status. Adult feeding results in notched leaf margins, reducing the plant's ability to produce energy. The most severe damage occurs underground, where larvae feed on the roots, disrupting water and nutrient uptake. This feeding behavior often makes the trees more susceptible to secondary root rot infections and leads to overall tree decline.

Control measures. Integrated Pest Management (IPM) is essential for controlling this beetle. Recommended strategies include:

• Application of foliar insecticides timed with adult emergence.
• Soil application of entomopathogenic nematodes or fungi to target larval stages.
• Cultural practices such as maintaining healthy soil conditions to support tree vigor.
• Regular monitoring of canopy foliage to track population density and determine treatment thresholds.