Large white cabbage butterfly

Pieris brassicae

1. Identification

• Common name: Large white cabbage butterfly
• Scientific name: Pieris brassicae L.
• Order: Lepidoptera
• Family: Pieridae

2. Pest description

• Adults: Medium-sized butterflies (≈ 50–65 mm wingspan); white wings with black spots on the forewings; females with two additional circular spots.
• Larvae: Yellowish-green caterpillars with black spots and fine hairs; up to 40 mm long; gregarious in the first instars.
• Eggs: Yellow, elongated, laid in clusters on the underside of the leaves.

3. Main hosts

• White cabbage, cauliflower, broccoli, kale and other cultivated Brassicaceae.
• Wild Brassicaceae (e.g.: Sinapis spp., Raphanus spp., Brassica spp.).

4. Symptoms and damage

• Intense defoliation caused by the caterpillars, especially in the first gregarious instars.
• Irregular perforations in the leaf blade.
• Severe damage to seedlings and young plants.
• Contamination of the leaves with excrement, reducing the commercial value.

5. Biological cycle

• Winter spent as a chrysalis in shelters in the vegetation or structures.
• Adults emerge in spring, with several generations per year.
• Females lay eggs in clusters on the underside of the leaves.
• Caterpillars feed intensively for 2–3 weeks before pupation.
• 2 to 4 generations per year, depending on weather conditions.

6. Monitoring

• Observation of the underside of the leaves to detect egg clusters.
• Counting of caterpillars in the first instars.
• Visual monitoring of adults in flight during spring and summer.
• Assessment of defoliation in young crops.

7. Management measures

• Cultural: Manual removal of egg clusters and caterpillars; elimination of wild Brassicaceae; crop rotation.
• Biological: Conservation of natural parasitoids (e.g.: Cotesia glomerata); use of Bacillus thuringiensis in young larval stages.
• Integrated protection: Intervention based on monitoring; preference for selective products compatible with natural enemies; avoid late treatments due to lower efficacy on developed caterpillars.

Bibliographic references

• EPPO Global Database – Pieris brassicae.
• CABI Invasive Species Compendium – Pieris brassicae.
• Alford, D. V. (2007). Pest and Disease Management Handbook.
• Salisbury, A. et al. (2015). Ecology and management of Pieris brassicae.