Crucifer weevil

Systematic position: The crucifer weevil (Ceutorhynchus denticulatus) belongs to the order Coleoptera and the family Curculionidae. It is a highly specialized pest that targets cruciferous plants, making it a critical concern for agricultural production in regions where canola and mustard are essential crops.

Host plants: The primary hosts for this weevil include oilseed rape (winter and spring varieties), mustard, and various related cabbage species. The pest thrives by feeding on both cultivated crops and wild cruciferous weeds, which often act as bridges for the pest to colonize new fields.

Biology and lifecycle: Adult weevils overwinter in the soil or under leaf litter. In the spring, they emerge and start feeding on host tissues. Females lay eggs inside plant parts, typically within buds or developing stems. Once the larvae emerge, they feed internally, causing significant hidden damage before exiting the plant to pupate in the soil.

Damage and economic impact: The larvae cause direct damage by feeding on the internal tissues of buds and developing pods, which results in stunted growth, bud abortion, and reduced yield. Adult weevils also contribute to crop stress by grazing on leaves and stems, leaving small holes that can facilitate the entry of pathogens or weaken the plant’s overall vigor.

• Implement effective crop rotation cycles to disrupt the pest lifecycle.
• Destroy cruciferous weeds on field borders to reduce early infestation levels.
• Use yellow sticky traps to monitor adult weevil activity during the spring.
• Apply systemic insecticides during the critical stages of bud development if economic thresholds are exceeded.
• Perform deep tillage after harvest to bury and eliminate overwintering pupae and larvae.