The Tomato Leaf Miner is the caterpillar of a Gelechiid moth. The caterpillar tunnels and feeds in mines between the upper and lower surfaces of tomato leaves. Larger caterpillars burrow into stems and green tomato fruits. Uncontrolled outbreaks of Tomato Leaf Miner can devastate a tomato crop and reduce yield to zero. Understandably tomato growers want to keep this pest out of the United States.
Actions to prevent this pest from invading the US may change some marketing practices. Vine ripe tomatoes have become popular with consumers and are packaged with portions of the vine attached. These can be produced in the US in summer, but in the off season, fresh tomatoes are imported. However, importing tomatoes with any green stems or leaves attached from areas with tomato leaf miner carries a high risk of introducing tomato leaf miners that may be living those plant parts. One step of prevention would be to impose strict regulations such as a ban on import of tomatoes with stems and leaves and enhanced inspections of tomatoes.
Pheromone traps based on the pheromone of the female are useful for detecting populations of adults. Monitoring traps can give early warning that the pest has invaded. However, pest populations often escape detection until they reach a large size. Then, it may be too late for local quarantines and eradication to be effective. It is important for those growing tomatoes to recognize the insect, its damage and vigilantly report it. The Tomato Leaf Miner can be managed to reduce the damage, but management adds additional costs. The best management practice is to prevent entry to the United States.