Tomato Leafminer

Adults are small, greyish moths with mottled, fringed wings that are active mainly at dusk and rest on the plant during the day. Larvae are small and cream to greenish, often with a darker band behind the head. The most conspicuous sign is the larval mine: an irregular, blotchy, translucent tunnel within the leaf that later turns brown.

Larvae also bore into stems, growing points, and fruit, leaving entry holes and internal galleries often accompanied by dark frass. The blotch mines and fruit galleries distinguish this pest from the narrow, serpentine mines of true leaf-mining flies.

Females lay small eggs on foliage, stems, and young fruit. Larvae mine and bore through several instars before pupating on the plant, in the soil, or in mines, and the life cycle is short in warm weather, giving many overlapping generations per year, especially in protected tomato production where conditions are favourable year-round.

The pest can persist wherever host plants are available and moves readily with the trade in tomato fruit and plant material, which has driven its rapid international spread.

Leaf mining reduces photosynthetic area and, when heavy, can lead to extensive drying of foliage. Boring into growing points can distort growth, and tunnelling into fruit causes direct damage and entry points for rots, making fruit unmarketable. Losses can be severe where populations are not managed, particularly under protected cultivation.

Tomato is the principal host. The pest can also develop on other solanaceous crops such as potato and eggplant, though damage is usually most important on tomato.

Pheromone traps are used to detect adults and monitor activity, and plant inspection focuses on finding fresh mines, damaged growing points, and fruit galleries. Early detection is especially important given the pest’s rapid population growth, and in regulated areas surveillance supports quarantine decisions.

Effective management integrates exclusion, biological control, sanitation, and careful use of selective products, coordinated with any regulatory requirements.

• Use exclusion measures such as insect netting and clean planting material in protected culture
• Conserve and release natural enemies, including predatory bugs and parasitoid wasps where available
• Practise strict sanitation, removing and destroying infested plants, fruit, and residues
• Rotate modes of action and rely on selective products to slow resistance and spare beneficials
• Follow quarantine, monitoring, and reporting requirements in regulated areas