A leaf miner is a broad term for various species of insects while in the larvae stage of their life cycle. Sawflies (Hymenoptera), flies (Diptera), beetles (Coleoptera), and even some moths (Lepidoptera) all have leaf-mining larval stages.

Once hatched and in the larvae stage, miners appear to be like small worms about ⅛ to ¼ inch in length, pale yellow to white. 

In the pupae stage, they are often referred to as “bugs that look like rice”.

Adult miners resemble a house fly with wing colors ranging from pale yellow to white.  Here are some examples of the different stages of leaf miners:

The lifecycle of leaf miners depends on the insect species it will become (fly, beetle, moth, etc.).

After adult miners lay the eggs, the eggs will be present inside or on the leaves’ surface for a few days to several weeks.

The larvae stage, in which they cause damage to trees and shrubs, ranges from a few weeks to a few months.

The pupae stage lasts anywhere from a few days to a few weeks, and once becoming an adult,
miners survive for a few weeks to several months.

In the adult stage, leaf miners mate and reproduce new generations.

Leaf miners cause damage to plants while in the larvae stage as they feed on the tissue of plant leaves, leaving behind dead tissue, which looks like white lines of leaves. Although leaf miners can only damage a plant while in the larvae stage, it is essential to eradicate them in any stage of their life cycle to prevent future generations from emerging.

You can identify leaf miners by the visual damage left behind on the leaves of plants. As the larvae feed on the leaves of plants, they will leave behind patches or tunnels, appearing yellow or white, of dead leaf tissue. Here are some examples:

Leaf miners are attracted to various plants, including edible plants such as tomatoes, cucumbers, lettuce, etc., and ornamental shrubs such as roses, azaleas, and boxwoods.

The most effective way to prevent leaf miners damage is to routinely inspect your trees, shrubs, and plants for any early signs of leaf miners activity.

If you find leaf miner tunnels on your plants, squash the larva at the end of the tunnel. You can remove the infected leaves from the plant if it has enough other leaves to manage. Do not remove more than 1/3 of the leaves on any plant.

Another way to prevent leaf miners is to practice good sanitation by removing weeds and dead plants during and after the season. Also, after the season is over, aerate the soil. This will bury and destroy the pupa stage, and they will die.
Aeration breaks the lifecycle of leaf miners.

Leaf miners can be challenging to eliminate because their larvae spreads within the layers of plant leaves. Some common DIY ways to get rid of leaf miners include:

• Pruning Away leaf miner damage
• Squeeze affected leaves to remove leaf miners
• Planting “trap crops” to entice leaf miners to seek out certain plants as sacrificial plants, thereby protecting your treasured trees and shrubs