The Problem
- A leaf miner is any one of three species of insects in which the larval stage lives in, and eats, the leaf tissue of plants.
- The adult female uses her ovipositor to insert the eggs inside the leaf where the larvae spend a safe and secure childhood, munching away on the leaf tissue while protected by the leaf’s upper and lower cuticles.
- Leaf-mining insects come from one of three insect orders, but most of those in our area are flies.
- Leaf miners tend to have three generations per growing season, so that one untreated infestation can result in an increased problem as the season progresses.
Adult flies usually just look like a compact version of a housefly.
Signs of damage
- Leaves have tunnels throughout the interior.
Controls
- Once you’ve noticed the problem, the larvae are in their protected space.
- The best you can do is to remove all infested leaves and grind them into a pulp - with your foot — thereby killing the larvae.
- Prevention is the best control, and row covers are the most effective control.
- Sticky tapes can reduce the population of adult flies, but can also affect beneficial insects.
- Since the leaf miner flies over-winter in the soil (in their pupal stage), turning over the soil where infested plants were grown can help control future outbreaks.