Tomato leafminer

Tuta absoluta

1. Identification

• Common name: Tomato leafminer
• Scientific name: Tuta absoluta Meyrick
• Order: Lepidoptera
• Family: Gelechiidae

2. Pest description

• Greenish to cream caterpillars, reaching 7–10 mm, highly mobile and with great capacity to penetrate tissues.
• Small, greyish adults, with narrow, fringed wings; wingspan of 8–10 mm.
• Leafmining species, causing galleries in leaves, stems and fruits.
• Highly destructive pest, with great dispersal capacity and resistance to insecticides.

3. Main hosts

• Tomato.
• Potato and other cultivated solanaceous plants.
• Wild solanaceous plants that act as a reservoir.

4. Symptoms and damage

• Serpentine galleries in the leaves, reducing the photosynthetic area.
• Perforations and galleries in green and ripe fruits, with dark excrement inside.
• Perforations in stems and petioles, compromising plant development.
• Very high yield losses in severe attacks.

5. Biological cycle

• Eggs laid singly on the underside of leaves, stems or fruits.
• Caterpillars develop over 2–3 weeks, feeding inside the tissues.
• Pupation in silken cocoons on the plant, in the soil or on support structures.
• Adults emerge throughout the year in greenhouses; several generations per year, accelerated by high temperatures.

6. Monitoring

• Direct observation of galleries in leaves and fruits.
• Pheromone traps for early detection and tracking of flight peaks.
• Regular sampling of young leaves and green fruits.
• Reinforced monitoring in greenhouses, where the pest develops continuously.

7. Management measures

• Cultural: removal and destruction of plant debris; rigorous sanitation of greenhouses; crop rotation.
• Preventive: elimination of wild solanaceous plants; use of insect‑proof nets; inspection of seedlings before planting.
• Biological: Mating disruption; application of Bacillus thuringiensis at young stages; use of specific parasitoids and predators.
• Integrated protection: definition of intervention thresholds, judicious use of authorised insecticides, rotation of modes of action and integration with trap data and phenological models.

Bibliographic references

• CABI – Invasive Species Compendium – Tuta absoluta.
• EPPO Global Database – Tuta absoluta.
• Alford, D. V. (2007). Pest and Disease Management Handbook. Blackwell Publishing.
• Desneux, N. et al. (2010). Biological invasion of the tomato leafminer. Journal of Pest Science, 83, 197–215.
• Biondi, A. et al. (2018). Integrated management of Tuta absoluta in tomato crops. Pest Management Science, 74, 2225–2236.