Plant pests are among the most annoying challenges for a gardener. They can affect indoor house plants, greenhouse plants, or outdoor plants. Plant pests are unsightly, and they can cause serious damage to the foliage of your beloved plants.
Although there are many different types of pests that can affect your plants, leaf miners are among the most unpleasant ones. Usually, they don’t cause extensive damage, but they ruin the foliage of many plants. Left untreated, leaf miner damage can be a gateway to various diseases, and it can even end up killing the plant.
But the good news is that as it goes with most plant pests, you can get rid of leaf miners. In the following guide, we will provide you with some useful tips for identifying leaf miners.
We will also give you some excellent suggestions for dealing with these nasty pests. Like always, our solutions are non-invasive and chemical-free.
What are Leaf Miners?
A leaf miner is not a singular type of pest. It is a general term that describes any type of insect larvae that live within a leaf. The larvae that nest within the leaves also feed on the leaves, spoiling their aspect. In most cases, these larvae cause minimum damage. They mostly ruin the look of the plants that they live on. However, a few pests can evolve into severe infestations. In such cases, they can pose a risk to the plant’s life.
Leaf miners can be found in most parts of the world, from America to Europe, Asia, and even Africa and Oceania. Leaf miners usually spread through the importation of infested plants. The pests can be found on the leaves, or they can hide in the soil.
There are over 300 species of leaf miners. The most common leaf miners are caterpillars, beetles, sawfly larvae, and maggots of true flies. However, the most common pests are not also the most dangerous ones. The most troublesome leaf miners are Liriomyza Sativae (vegetable leaf miner), Liriomyza Cicerina (chickpea leaf miner), Liriomyza Trifolii (American serpentine leaf miner), Liriomyza Bryoniae (tomato leaf miner), and Liriomyza Huidobrensis (Serpentine leaf miner).
Leaf miners pose a serious threat to several crops. The most affected ones are melons, potatoes, onions, cotton, grains, and different vegetable crops. So, if you have a vegetable garden, you should keep an eye out for leaf miners.
Not sure what leaf miners look like? Here’s how you can identify them.
How to Identify Leaf Miners
Identifying the pests that you are dealing with is critical and it’s the first step towards getting rid of them. There are many remedies that work on several types of pests, but some remedies are single-purpose. So, it is important to apply the right pest removal solutions from the start. This way, you don’t waste time and you prevent the infestation from getting more severe. There are two ways in which you can identify leaf miners: by their damage and by the larvae.
Identifying leaf miner damage
Leaf miners cause very distinctive damage to plant leaves. Like their name suggests, the larvae mine, causing tunnels in the surface of the leaves. In some cases, the damage is not shaped like a tunnel, but like a blotch. This usually happens when more than one larva is living within a leaf, and their tunnels join.
Identifying the larvae
Unlike other types of plant larvae which live under the leaves or in the soil, leaf miners live within the leaves. They can live there because they are very flat. The tunnels or the blotches that they cause on the leaves have a thin cover. By breaking that cover, you should expose the tiny larvae.
Identifying the severity of an infestation
Usually, leaf miners spread when you bring home infested plants or cuttings from infected plants. Your plants can also get infected by the larvae or adult insects found in the soil. Once the larvae complete their first development stage, they fall on the ground. In the soil, they enter their pupal stage. Once they turn into adults, they fly and lay their eggs on the leaves. These pests are common outdoor. They don’t usually attack indoor plants, but bringing infested plants indoors can infest healthy indoor plants.
Larvae damage is mostly cosmetic. It has almost no effect on a plant’s growth. However, a large population of larvae might slow growth and cause leaf drops. Adult plants are more resilient, but seedlings can sustain severe damage. Since each larva digs its own tunnel, a quick inspection of the plant leaves will tell you how severe the situation is.
How to Get Rid of Leaf Miners
You will find synthetic pesticides for leaf miners and other pests in any garden shop. However, we always prefer to take on a natural approach first, so that we avoid unnecessary plant damage.
In the following lines, we will give you some natural remedies for ridding your plants of leaf miners. You can combine various natural pest disposal ideas without worrying about hurting the plants. Natural remedies may take longer to yield results. However, they are safer for the plants, and they encourage a natural ecosystem that will prevent future pests and diseases.
1. Attract beneficial insects to your garden
The reason why some insects are called beneficial is that they fertilize the crops, clean up waste and they feed on plant pests. Ground beetles, ladybugs, praying mantises, lacewings, and soldier bugs are just a few of the many insects that can rid you of plant pests. To attract beneficial insects, you should give up chemical pesticides for good. Most chemical pesticides are just as harmful to beneficial insects as they are for pests.
Another great way to attract beneficial insects is to plant nectar-rich flowers. Use flowers of different heights to provide coverage for different types of good insects. Plants from the Aster family and the carrot family are particularly good at attracting beneficial insects. The Verbena family and the Mustard family are also preferred by good insects. Having a nearby water source will help. Mulch is also appreciated by earthbound insects.
2. Make natural pesticides with Neem oil
Neem oil is one of the most wildly used organic pesticides and for good reason. It does wonder repelling most types of plant pests and it poses no risk to beneficial insects.
Neem oil is an extract from the Azadirachta Indica tree. This is an ornamental shade tree found in South Asia. The oil can be extracted from most parts of the tree, but the valuable insecticidal compound is found in large quantities in the seeds.
Most commonly, neem oil is dissolved in water and sprayed on the affected areas. Simply add two tablespoons of oil to a gallon of water. When applied in the water it has an action time of 45 minutes, but it can also be applied in the soil. This way, it is absorbed by the plants and distributed to the tissues that the pests feed on. It also makes for a great fungicide, and it can do wonders for root rot.
3. Make natural pesticides with hot spices
Most pests hate spices. You can even deter some pests through companion planting and by planting aromatic herbs in strategic locations. However, when it comes to larvae, you must use the spices directly on the plant. One widely used remedy consists of a hot pepper spray. To make the spray mix cayenne pepper with garlic, organic liquid soap, and water. Strain the mixture and spray the liquid directly on the affected leaves. Spray on the front of the leaves as well as their undersides.
4. Manually remove affected leaves
This is a simple yet effective solution, especially if you are not dealing with a wide-scale infestation. Checking the plants and removing the affected leaves by hand can be a tedious job. Nonetheless, removing the larvae means that you are halfway through dealing with your pests. All that is left are the adults that laid the larvae.
5. Trap adult pests with sticky traps
Most of the annoying insects that produce leaf miners are flying insects that can easily be trapped on sticky traps. You can find sticky traps of different colours which attract different types of harmful pests. The problem with sticky traps is that they can also appear attractive for beneficial insects. As such, try to only use this as a last resort.
6. Use beneficial nematodes
We may not be a fan of soil worms, but we all know that most of them have their purpose in an ecosystem. Beneficial nematodes are members of the Steinernematidae and Heterorhabditidae families. They look like colourless roundworms. They stand out from other worms through their non-segmented elongated shape.
Beneficial nematodes can be used to eradicate a wide range of pests from caterpillars to cutworms, grubs, crane flies, fungus gnats, and others. They are extremely efficient for soil-borne pests. They attach to the pests, which they use as hosts, feeding off them until they mature.
You can find beneficial nematodes sold in soil drenches or sprays. To ensure an optimal survival rate apply them in moist and warm soil.
7. Use Diatomaceous Earth
Another way to get rid of the adult soil-borne insects that produce leaf miners is with Diatomaceous earth. This is a powder made of a naturally occurring sedimentary rock. It works against pests by absorbing the lipids from the outer layer of their exoskeletons. This powder is also known as fossil shell flour.
8. Spray Spinosad on affected plants
Spinosad is another naturally occurring insecticide. It is found in the soil, and it is sold as a liquid soap spray. It affects the nervous system of the pests that touch it or eat it. This causes uncontrollable muscle flexes which leads to paralysis and ultimately death. It is low in toxicity for people and animals, but it can cause mild skin and eye irritations.
The only side effect of Spinosad is that it is toxic to bees. However, it has a short time of action. So, if you only spray the remedy in the evenings and avoid the flowering season altogether, your local bee population should be fine.
9. Get rid of the larvae with parasitic wasps
This is a great biological remedy for leaf miners and other pests in larval stages. The adult female wasps kill the larvae in their tunnels and lay their eggs on them. As they grow, they use the dead larvae as food.
For the best results, release the wasps between the leaves in the morning or in the evening. The wasps are most effective in warmer climates so the temperatures should exceed 15°C. Keep in mind that these wasps have a short lifespan. You should use them as soon as possible after acquiring them. Consult a specialist to make sure that you are applying the right dosage.
10. Use crop barriers
Covering your crop rows with plastic covers is a great way to keep leaf miners and other parasites away from your plants. This method also keeps hibernating larvae from appearing in the spring. It also prevents the existing larvae that live within the leaves from dropping to the ground. Without having contact with the soil, the larvae cannot evolve into adults. Without adult pests, there can be no future larvae.
Floating row covers can also make for great barriers as they prevent the females from landing on the leaves and depositing their eggs.
As you can see, there are countless effective solutions that you can try if you want to get rid of leaf liners and prevent them from reappearing. It is important to remember that the main goal should be creating a healthy ecosystem that has a naturally low occurrence rate of pests and diseases. Chemical pesticides might rid you of pests fast, but their results are only short-term. In the long run, chemical pesticides harm the nearby ecosystem and favour the development of pests and diseases.
Moreover, natural remedies are quite effective. They are ideal for edible crops which you should try to keep as chemical-free as possible. By using the solutions described in our article, you will also protect the local population of pollinators and other beneficial insects.
Have you had problems with leaf miners? Let us know in the comment section!