Yellow-striped weevil

The yellow-striped weevil (Naupactus xanthographus) is a member of the Curculionidae family and represents a significant agricultural pest, particularly in South American fruit and grape production. Due to its polyphagous nature, it poses a recurring challenge for farmers managing diverse cropping systems.

This pest affects a wide range of botanical hosts, including various fruit trees (pome and stone fruits), citrus, grapes, and several berry crops. Its ability to feed on different plant species makes it a persistent threat in orchards where weeds or alternative host plants are not properly controlled.

The life cycle of the weevil is complex, involving both foliage-dwelling and soil-dwelling stages. Adults are active on the canopy, feeding on leaves and mating. Females lay eggs on bark or leaves, after which the larvae descend to the soil. The larval stage is spent underground, where they feed on roots, eventually reaching the pupal stage in earthen chambers.

Damage to crops is twofold: adults cause foliar damage by notching the edges of leaves, which can reduce photosynthetic capacity. However, the most severe damage is caused by the larvae, which feed on root systems, causing stunted tree growth, decreased yields, and potentially the death of young trees due to root decay and secondary infections.

Effective management requires an integrated pest management (IPM) approach. Control measures focus on applying insecticides during the adult emergence phase to disrupt egg-laying. Soil treatments or the application of entomopathogenic nematodes are recommended to target larval populations in the soil. Maintaining orchard hygiene, including weed management, significantly reduces available niches for this pest.

• Monitoring adult populations using visual inspection and traps.
• Timing insecticide applications to match the period of adult emergence.
• Using biological control agents like entomopathogenic nematodes against larvae.
• Implementing strict phytosanitary measures for nursery stock.