Leaf Miners

leaf miner in gardenThe name “Leaf Miner” is used to refer to the larval or maggot stage of an insect that feeds upon the leaves and greenery of many valuable garden crops, including lettuce and cabbage, beans and peppers, berries, and a wide variety of flowers and citrus trees and shrubs, among others. While most plants can withstand a great deal of damage and remain quite healthy, the damage from leaf miners can be unsightly. Moreover, they will reduce the saleable value of most crops quite quickly. Continue reading to learn how to organically reduce these nuisance critters before they invade your plants and do noticeable damage.

Dealing with a Leaf Miner Problem

As with any pest problem, the first step to treatment is identification. Adult leaf miners look quite similar to typical house flies. They tend to average 1/10 of an inch in length. In addition to being black or grey in color with yellow stripes and clear wings. Larvae look like tiny worms or maggots, approximately ⅓ inch long, colored green or pale yellow. Eggs can be found laid underneath the surface of the leaf and may appear as tiny raised spots which will hatch within ten days.

As leaf miners feed, they create clear, winding tunnels through leaves and other greenery, leaving behind a trail of black fecal matter. The danger to leaves comes from the possibility of bacteria or fungi entering these tunnels, in which case the leaves will turn yellow and fall.

leaf miner damage
Damage to leaves from leaf miners

Getting Rid of Leaf Miners

As we always recommend with organic garden pest control, the best method for maintaining healthy crops is to encourage the vitality of your soil, and the life cycles of beneficial insects which help keep the environment in balance. We discourage the use of pesticides, as this will destroy these beneficial insects and will almost surely lead to even more destructive outbreaks down the road.

Check Your Plants Regularly

Monitor your plants closely and crush any tunnels between your fingers to kill any larvae present within. The best way to prevent an overabundance of leaf miners is early detection, so be vigilant. If you spot any infested leaves, pick them and toss in the trash away from the garden.

Keep Plants Healthy

Maintain the health of your plant by composting and fertilizing as necessary according to the needs of your individual plant. We are here to help with specific instructions for fruits, vegetables, herbs, and more.

Cover Your Crops

Physical remedies such as floating row covers or sticky traps can be utilized as necessary, but bear in mind the individual limitations of each. Row covers are not suitable for crops that require pollination, and sticky traps will not help in the larvae stage.

Use Beneficial Insects

A better alternative may be to purchase beneficial insects such as the parasitic wasp diglyphus isaea. These little guys will handle your pest problem in no time. Plus, you can attract them naturally or purchase them to release in your garden.

We especially recommend this option for those growing indoors. 

Use Botanical Insecticides

Botanical insecticides or neem oil (affiliate link) can be used.  But, this should only be used as a last resort. These will break down faster in the environment than traditional pesticides. However, they will still repel your beneficial insects and disrupt the balance of your garden.

Remember that, while leaf miners are not the worst pest that could visit your garden, too many of them can make your plant susceptible to infection. Or worse, severely decrease its vitality. Early detection and prevention through a balance of beneficial insects and healthy soil are key. Let us know if you have any additional questions.
Happy Gardening!