White Lines On Tomato Leaves | Tomato Leaf Miner Control

Time to Read 5 Minutes.

White lines on tomato leaves are another common pest problem that many home gardeners experience. Sometimes you may see these white lines on tomatoes. Larvae create these white liners on the plant. This insect is called a tomato leaf miner.

The larvae of a variety of insects are responsible for this problem. After the insects lay their eggs on the leaves, a tiny larva emerges after the eggs hatch. The larvae then consume the cells of the leaves.

As a gardener, we always like to use organic pest control methods. In this article, I’m going to discuss how to get rid of leaf miners naturally? 

What causes white lines in tomatoes?

White lines on tomato leaves caused by larvae on the leaves. These leaf miner insects eat the cellulose of the tomato plants, and once they have eaten, the damaged part turns white. That is why we can see small white stripes on tomato leaves and fruits.

Initially, tomato leaf miner damage is minimal. Heavy infection can lead to tomato leaf scorch and leaf drop.

These tiny pests affect the tomato leaves’ photosynthesis. Because leaf miners eat mesophyll cells, these cells contain chlorophyll which is essential for absorbing light to photosynthesis.

As these insects eat mesophyll cells, leaves lose the green color, and tomato plants are unable to absorb sunlight for photosynthesis. Inhibition of this photosynthesis will stunt tomato plant development and yield.

These insects have four life stages: egg, larvae, pupa, adult moth. Their eggs are white or yellow and hatch in around seven days.

Moths, sawflies, and beetles are common insects that lay eggs on tomato leaves. These larvae have the appearance of worms or maggots. Some mining insects are attracted to tomatoes and flower petals.

How do you control leaf miners organically?

Tomato leaf miners can control using a variety of organic methods. You can use neem oil, spinosad spray, or white oil, but don’t combine them all together. Because mixing everything as a single solution can burn the leaves, you should avoid it. 

These organic treatments help to get rid of white lines on tomato leaves. Do not apply water for 24 to 48 hours once this treatment is sprayed to leaves. Water will wash away the liquid pesticide, and it will make the treatment less effective.

Tomato leaf miners live inside the leaves, making tunnels through the tissues.

These treatments only damage the eggs under the leaves of these insects, as these larvae are present inside the leaf, and these soluble tomato leaf miner treatments do not penetrate the leaves’ cells. This limitation applies to all chemical or organic treatments. It can use to control future larvae populations.

Remove infected leaves.

Remove all of the infected tomato leaves from the plant at this point if it is seriously impacted. If only a few leaves are being attacked, there is no need to remove those leaves.

Isolate the infected plant.

Generally, leaf miners attack one or two plants at a time. Once you notice the infection at the initial stage isolates the plant, and this will help prevent further infection to other plants. Isolation can be done mainly in two ways, covering the plant using transparent polythene cover or moving the plant to a separate area for two or three weeks. The second option is suitable when growing tomatoes in pots.

Neem oil for leaf miners.

Neem oil is an excellent tomato leaf miner pesticide that can affect their eggs’ fertility and further spread. This organic solution does not destroy the larvae, because the insect lives inside the leaf. But neem oil can destroy leaf miners’ eggs. Azadirachtin is the main chemical in neem oil and it is toxic to insects. That chemical interrupts the metabolism of insects.

Neem oil extract (Hydrophobic extract of neem oil) does not have the Azadirachtin chemical, therefore always choose cold-pressed neem oil. Basically, neem oil extract is the same as a vegetable, sesame, or coconut oil. When shopping always choose “cold-pressed neem oil” for the highest results (source).

How to use neem oil for leaf miners.

• Neem oil and water do not mix together. Therefore we have to use an emulsifying agent, and we can use liquid soap to emulsify neem oil. Alternatively, you can use the liquid hand wash as an emulsifying agent.
• Mix 4 tablespoons of neem oil with 1 teaspoon of liquid soap.
• Then mix the neem oil solution with 1 gallon of water.

The solution must be thoroughly dissolved before it can be used. Spray all parts of your tomato plant, paying special attention to the areas underneath the leaves. These bug eggs are placed beneath the leaves by the female insects.

Neem oil can be applied to tomato plants at any time of day, but it is most effective in the early morning or late evening. At this time leafminer pests are active, and using this product in direct sunlight may cause leaf burn.

Reapply the neem solution every 3 or 4 days until tomato leaf miners disappear.

Spinosad Spray.

Spinosad spray is another good insecticide that can be used to eliminate tomato leaf miners. This insecticide is also an organic treatment. You can find spinosad spray bottles in local shops or online stores.

Spinosad is made from the fermentation of soil bacterium. This organic leaf miners chemical is toxic to harmful insects and does not affect beneficial insects.

Mix the spray as recommended by the manufacturer and spray well all over the tomato plant, especially under the leaves. These pest eggs are placed at the base of the leaves.

Spray the spinosad solution on your tomato plants every five days until the leaf miners have disappeared from your plants.

White oil spray.

White oil is another excellent tomato leaf miner organic control oil. Generally, oil-based pesticides are effective for soft body pests, and this solution blocks the insects breathing. Oil and water do not mix, therefore we have to use an emulsifying agent. Soap is a good emulsifying agent.

How to use white oil for leaf miners.

• Mix four teaspoons of vegetable oil with one teaspoon of liquid dishwashing soap. Using a stick or spoon mix the solution. Once it is concentrated it turns to white color.
• Pour the solution into a bottle and shake well.
• Dilute the concentrated white oil by mixing two cups of water. Thoroughly mix the solution and then pour into a spray bottle and spray everywhere in the tomato plant, including underneath the leaves.

The best time to apply white oil for tomato leaf miners is early morning or evening. In these times, insects are active.

Wood ash.

Wood ash is another alternative pesticide that can be used for tomato leaf miner control. Collect dry wood ash and sprinkle on leaves. This is not as powerful as the treatments mentioned above, though it can limit the insects’ activities on tomato plants. The best time to apply wood ash for tomatoes is early morning or evening.

You can use this simple treatment while using other leaf miners’ treatment. However, do not apply wood ash to tomato plants immediately after spraying neem oil, spinosad, or white oil.