Everything to Know About Leaf Miner: Identification and Control

Have you ever noticed that there are white trails that fill the surface of your plants? It may look aesthetic, but be careful because it is a sign that your grower has been under attack by a leaf miner.

Although the damage looks insignificant, the leaf miners can make your crops fail if you do not get treatment right away. These insects will eat away at the plant slowly until it is too late.

Identification

Leaf miner is any one of numerous species of insects in which the larval stage lives in, and eats, the leaf tissue of plants. Frequently, it appears as yellow, squiggly lines in the leaves.
Leaf Miner

There are several types of leaf miners scattered all over the world, but they all look similar. Its name refers to the number of larvae that live inside the leaf and eat away the interiors.

However, traces of its larvae are visible from the leaf surface as pale white streaks. Once mature, these insects will grow into flies that will not touch the plants.

In general, the following are some types of leaf miners we know.

  • Citrus Leaf Miner (Phyllocnistis citrella)
  • Tomato leaf miner (Liriomyza bryoniae)
  • Vegetable leaf miner (Liriomyza sativae)
  • American serpentine leaf miner (Liriomyza trifolii)
  • Spinach leaf miner (Pegomya hyoscyami)
  • Chickpea leaf miner (Liriomyza cicerina)
  • Serpentine leaf miner (Liriomyza huidobrensis)

For your information, larvae are usually 1/3-inch-long with a pale yellow or green hue. Meanwhile, the adult one usually reaches a length of up to 1/10 inch with gray and yellowish stripes.

The Life Cycle

Liriomyza is a genus of leaf miner flies in the family Agromyzidae and commonly known as the vegetable leaf miner.
Leaf Miner Liriomyza

The flies will be active in spring. They will grow well into young adults in this warm season. After that, these insects begin to mate and produce eggs.

Once breeding, the female parent will produce up to 250 eggs which she lays on the surface of the leaf epidermis. Within ten days, they will hatch and produce larvae.

The larvae will instinctively enter the leaf and start living in it. They will be there for approximately 2-3 weeks before they are finally ready to pupate and leave the leaves.

Then, they will fall to the ground and begin to develop there. These insects stay in the soil 1-2 inches deep for approximately 15 days before becoming adult flies.

Dealing with Leaf Miner Damage

Leaf miner will chew maze-like trails along the leaves of plants, disfiguring them and putting them at risk.
Leaf Miner Trail

Each type of leaf miner may cause the not-same damage. Generally, they attack different plants, ranging from spinach, citrus, elm, hawthorn, and others.

However, in general, the scars that appear are relatively similar.

In the early stages of infestations, you will notice trails on the leaves and stems. If you split them, there will be many larvae inside of the tissue, and it leaves much damage.

This pest does not kill the plant but reduces the quality of the harvest. The growers will lose hardiness. It will become weaker and lead to a poor harvest due to an unattractive appearance.

Besides, eating crops with larvae inside is not something you would choose. Even though the plant experts have stated that the larvae are harmless to consume, you will think twice about cooking them.

Another danger, the tunnel that the larvae leave can invite germs such as fungi and bacteria that will cause damage to plants. It is such a difficult problem to overcome.

Leaf Miner Control

Citrus leafminer larvae feed by creating shallow tunnels, or mines, in young leaves of citrus trees.
Citrus Leaf miner

When dealing with pest problems, the most important thing you need to know is how to deal with them safely and effectively.

Each type of insect may have a different character that requires the not-same handling.

Using Leaf Miner Pesticide

The most common method to rid plants of leaf miners is to spray general pesticide on the infected plants. The trick to this method of how to kill leaf miners is to spray at right time. If you spray too early or too late, the pesticide will not reach the leaf miner larva and will not kill the leaf miner flies.
Get Rid of Leaf Miner

When dealing with pests, the first thing most gardeners think of is using pesticides. You can also do this method when dealing with this one insect.

There are various choices of chemicals that you can use to eradicate those annoying miners.

  • Spinosad. It comes from soil microorganisms that will help control plant pests. Its use is safe for the environment.
  • Broad spectrum-type. Some examples are carbaryl, permethrin, and bifenthrin. Its use is very effective but can kill good microorganisms in the soil and plants.
  • Botanical insecticides. This option should be the last thing you do when the bugs are getting out of control.

Although this insecticide works very quickly, the chemicals in it will kill all microorganisms and disturb the balance of the environment.

If you use pesticides, start giving them to the spring. At this time, the adult insects begin to be active and will breed.

Apply pesticides evenly, and do not forget to do regular checks to ensure that all things are in a good condition.

How to Get Rid of Leaf Miners Naturally

Most of the time, this pest is identified by the leaf miner damage. Frequently, it appears as yellow, squiggly lines in the leaves. This is where the leaf miner larva have literally bored their way through the leaf. Leaf miner damage can also appear as spots or blotches.
Leaf Mine Sign

Many people believe that using pesticides is an effective way to get rid of pests. However, this may not apply to leaf miners.

In addition to damaging the environment, using chemicals sometimes does not show significant results. Applying them earlier or later will not kill these insects.

Instead of spending money on useless things, the natural way is better. Here are some methods you can do to deal with the invasion.

  1. Do It Manually

Pinch along the trails with your thumb and forefinger. You may be able to kill the larvae inside the leaf that way.
Pinch Leaf Miner

If the pest attack is not too severe, you can use the manual method to eradicate them. You can pinch the trails that appear on the leaf surface with your fingers. Thus, the larvae inside will die.

You can use this method as an initial preventive step before using pesticides or insecticides. But of course, do it patiently.

  1. Removing the Infected Part

You can cut out the part that have infected by leaf miner if it's still not to much strike your plants
Cutting Infected Leaf Miner Part

Pinching the leaf is the most basic way you can do when the invasion is not much. But if you find enough infected parts, then there is no harm in removing the trouble.

You can cut the leaves or stems that contain the larvae if possible. But make sure you throw the trash away from healthy plants that there is no chance of them coming back and attacking your growers.

The most popular way to get rid of it is to burn it. Thus, there is no hope for the larvae inside the leaf to survive.

  1. Using Beneficial Bugs

Leaf miner parasitic wasps (Diglyphus isaea) are the main natural enemy of these ubiquitous garden pests. These tiny wasps prey on leaf miners by laying eggs in their larvae. When the eggs hatch, the wasp larvae feed on the leaf miner larvae.
Use Natural Predator

Instead of you fighting alone, why not leave the pest business to the predators? You can spread wasps called Diglyphus isaea to the plant area to eradicate leaf miners that stick to various parts.

The beneficial bugs are also readily available at various plant shops that you will not have trouble getting.

But when using this method, make sure you spread the right amount of predators so that they do not damage your plants.

Prevention

Pick off and destroy badly infested leaves in small gardens. The more healthy the plant, the less chance that leafminers will hurt it. Maintain plant health with organic fertilizers and proper watering to allow plants to outgrow and tolerate pest damage. Keep your soil alive by using compost and other soil amendments.
Leaf Miner Prevention

However, prevention is better than cure. Before dealing with leaf miner damage, you should take precautions in advance that these insects have time to launch an attack.

There are several easy ways to prevent those pests from getting to your favorite plants, ranging from the simplest way to using chemicals. Here are some of them:

  1. Performing the Periodic Checks

The best way to prevent leaf miner is to do periodic check with your plant. Maybe it's tiring, but this method is the best way to prevent leaf miner.
Leaf Miner Periodic Check

It is the first thing you should do to prevent any invasion of your plants. No matter how wide your plot of land, regular checks are the key to find out and make sure everything is okay.

Besides leaf miners, regularly checking is also very useful to find out the potential for your harvest later.

You can also estimate what kind of maintenance is suitable for your plants so that the results are more profitable.

  1. Keeping the Garden Clean

Eradicating the leafminer larvae is key to preventing them from infesting your garden. Keeping a 'clean' garden will naturally deter infestations from destructive insects.
Garden Cleanliness is One of the Keys to Avoid Pests

One of the causes of the emergence of pests is unsanitary environmental conditions. Any dirt will attract leaf miner flies to place their eggs on the plant’s surface.

It is the beginning of the terrible invasion you have to face.

Therefore, make sure you clean the garden properly. Eliminate all forms of weed that invite leaf miners to forage.

If you start to find signs of the presence of pests, no matter how small, get rid of them immediately in the most environmentally friendly way.

  1. Using Crop Cover

Using floating row covers such as AgFabric can help prevent adult flies from reaching your plants. If they can't reach the plant, they can't lay their eggs. And if they can't lay their eggs, the leaf miners can't leave trails! Yellow sticky traps are also a solution.
Crop Cover

The most traditional yet very effective way to prevent the leaf miner insect is to place a shield to cover the plant.

Use meshed netting row covers over the plants to protect them from any form of airborne invasion.

Unfortunately, this method will only be effective in areas that are still clean of leaf miners. If the larvae are already attached to the plant, they will survive under the covers and multiply rapidly.

Before installing, make sure your area has not been exposed to pests for the past year or so.

  1. Using Yellow Sticky Traps

Use yellow or blue sticky traps to catch egg laying adults. Cover soil under infested plants with plastic mulches to prevent larvae from reaching the ground and pupating.
Yellow Sticky Traps

If you see the presence of leaf miners in the garden, then take preventive action immediately. One easy way you can do this is to use yellow sticky traps. This method can kill the moth before it can breed.

These traps generally spread pheromones that will attract various species of insects, including the Citrus leaf miner.

Those who are attracted will approach and then become trapped in the sticky liquid. Gradually the pests will die on it.

  1. Using Fertilizer

One way to prevent leaf miner damage on leaves is to grow healthy garden plants. Organic gardening techniques using compost and fertilizers improve a plant’s hardiness. This makes the plant less susceptible to leaf miners and other garden pests.
Fertilizer for Healthy Plant

The easiest way to keep pests away from your garden is to ensure the health of the plants in it. When the leaves and stems are in top condition, the insects will not damage them either.

You can use the right fertilizer for your plants and ensure that the soil conditions and growers are healthy enough to avoid pests living in them. In addition to adequate nutrition, do not forget to water it as needed.

Conclusion

Citrus leafminer is a very small, light-colored moth, less than 1/4 inch long. It has silvery and white iridescent forewings with brown and white markings and a distinct black spot on each wing tip.
Citrus Leaf Miner Moth

That is a brief explanation of the leaf miner and how to solve it. But please be careful of fungal and bacterial attacks that may appear after the larvae leave the tunnel in the leaf.

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