Cabbage stem weevil

Ceutorrhynchus quadridens

1. Identification

• Common name: Cabbage stem weevil
• Scientific name: Ceutorrhynchus quadridens Panzer
• Order: Coleoptera
• Family: Curculionidae

2. Pest description

• Adults: Weevils 2.5–3.5 mm long, dark grey body with light scales, short rostrum and geniculate antennae; predominant activity in early spring.
• Larvae: Apodous, whitish, curved body and brown head; develop inside the petioles and young stems.
• Pupae: Formed inside the stem or in the nearby soil.
• Eggs: Laid in the petioles or at the base of young leaves.

3. Main hosts

• Cabbage, cauliflower, broccoli and other Brassica oleracea.
• Other cultivated or wild cruciferous plants, including Brassica rapa, Sinapis spp. and Raphanus spp.

4. Symptoms and damage

• Perforations in the petioles and young stems, with internal necrosis.
• Galleries inside the stem, causing structural weakening.
• Partial wilting, reduced vigour and delayed development.
• Possible predisposition to secondary fungal infections.
• In severe attacks, reduced head formation and lower commercial quality.

5. Biological cycle

• One generation per year, with adults active mainly in early spring.
• Adults emerge from the soil and feed on young leaves before egg-laying.
• Eggs laid in the petioles; larvae develop inside for 3–5 weeks.
• Pupation inside the stem or in the soil; adults overwinter until the following spring.
• Development favoured by mild temperatures and the presence of wild cruciferous plants.

6. Monitoring

• Observation of perforations in the petioles and young stems.
• Inspection of plants to detect internal galleries.
• Assessment of plant vigour, especially in plots with a history of the pest.
• Yellow traps can be used to detect adults in spring.

7. Management measures

• Cultural: Removal of wild cruciferous plants; crop rotation with non-host species; adequate incorporation of crop residues; sowing on dates that reduce overlap with the flight peak.
• Preventive: Early monitoring in spring; avoiding water and nutritional stress; choice of more tolerant varieties when available; avoiding excessive densities that favour humid microclimates.
• Integrated protection: Regular monitoring; intervention only when necessary; practices that reduce the attractiveness of plants and the survival of larvae in the soil.

Bibliographic references

• EPPO Global Database – Ceutorrhynchus quadridens.
• CABI Invasive Species Compendium – Ceutorrhynchus quadridens.
• Alford, D. V. (2003). Insect pests of crucifers.
• Williams, I. H. (2010). Insect pests of oilseed rape and other Brassicas.