Cabbage stem weevil

Systematic position: The cabbage stem weevil (Ceutorhynchus pallidactylus) belongs to the order Coleoptera and the family Curculionidae. It is a major pest frequently encountered in regions where cruciferous crops, particularly oilseed rape, are cultivated on a commercial scale.

Host crops: This pest primarily targets oilseed rape (winter and spring varieties). It also thrives on other Brassicaceae plants, including mustard, radish, cabbage, and various wild cruciferous weeds, which serve as alternative food sources throughout the growing season.

Biology and life cycle: The adults overwinter in soil or leaf litter. As temperatures rise in early spring, they emerge to feed on young host plants. Females insert their eggs into leaf petioles or stems. Larvae emerge inside the plant tissue and feed by tunneling, which disrupts the structural integrity of the plant for several weeks before they drop into the soil to pupate.

Damage and harm: The larval feeding activity within stems and petioles is highly destructive. It causes the stems to crack and bend, leading to water and nutrient stress. In severe infestations, the plants may become stunted, prone to lodging, or susceptible to secondary fungal pathogens that enter through the feeding wounds.

• Implementing crop rotation with sufficient distance from previous rape fields.
• Deep tillage post-harvest to disrupt the pupation cycle in the soil.
• Using yellow water traps to monitor adult migration in early spring.
• Applying targeted insecticides when thresholds of adult presence are exceeded.
• Managing weeds in and around fields to remove alternative hosts for the weevil.