Corn earworm moth

Helicoverpa zea

1. Identification

• Common name: Corn earworm
• Scientific name: Helicoverpa zea Boddie
• Order: Lepidoptera
• Family: Noctuidae

2. Pest description

• Caterpillars with variable colouring (green, brown, pinkish), with longitudinal lines and fine pilosity.
• Medium‑sized adults, with yellowish to brownish forewings and light hindwings with a dark margin.
• Attacks mainly the reproductive structures of plants (flowers, fruits, ears).
• Highly polyphagous species with great dispersal capacity.

3. Main hosts

• Maize.
• Tomato.
• Cotton.
• Pepper and other solanaceous plants.
• Various horticultural and ornamental crops.

4. Symptoms and damage

• Perforations in the maize ears, generally at the tip of the silk.
• Intense consumption of forming grains, with the presence of excrement.
• Damage to tomato, pepper and other crop fruits.
• Significant reduction of commercial quality and yield losses.
• Internal damage that can favour secondary infections by fungi.

5. Biological cycle

• Several generations per year, especially in warm climates.
• Eggs laid singly on leaves, flowers or maize silks.
• Caterpillars develop quickly and are highly voracious.
• Pupation in the soil, where they remain until the emergence of the adults.
• Adults active during long periods, with strong migratory capacity.

6. Monitoring

• Observation of damage to the silks and tips of the ears.
• Inspection of young fruits in horticultural crops.
• Pheromone traps for detection and monitoring of flights.
• Assessment of the percentage of damaged ears or fruits.

7. Management measures

• Cultural: destruction of crop residues, crop rotation and synchronisation of sowings.
• Preventive: choice of less susceptible varieties and practices that reduce the attractiveness of plants.
• Biological: application of Bacillus thuringiensis in early stages and conservation of parasitoids such as Trichogramma spp..
• Integrated protection: regular monitoring, definition of intervention thresholds and judicious application of authorised insecticides.

Bibliographic references

• EPPO Global Database – Helicoverpa zea.
• CABI Invasive Species Compendium – Helicoverpa zea.
• Capinera, J. L. (2001). Handbook of Vegetable Pests.
• USDA IPM Guidelines – Corn Earworm.