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Citrus Leaf Miner Control and Treatment (Australia)

You can identify an attack of citrus leaf miner by the squiggly silver lines that will appear on the surface of the leaves.

Citrus leaf miners can be a problem for most citrus trees grown in Australia, even including some native citrus species.

While an attack from this pest will not kill your citrus tree, it will cause stunted growth and a reduction in fruit production.

What is a citrus leaf miner?

citrus leaf miner | Pest control
Citrus leaf miner damage / Photo by Toby Hudson / Wikimedia / CC BY-SA 3.0

The adult of the citrus leaf miner is a small moth that is only active at night. Its scientific name is Phyllocnistis citrella.

This tiny moth lays numerous eggs on the new leaves of citrus trees.

Once the tiny larvae emerge from the eggs, they tunnel their way through the leaves. This leaves squiggly silver lines on the leaves.

As a result, the leaves become distorted and are unable to conduct photosynthesis. This, in turn, stunts the growth of the tree.

Once the larvae are ready to pupate, they curl the leaf around in order to protect themselves. The entire process from egg to pupation only takes around 2 to 3 weeks.

What does citrus leaf miner look like?

Phyllocnistis citrella | Pest control
Citrus leaf miner / Photo by Jeffrey W. Lotz / Forestry Images, Wikimedia / CC BY 3.0

The citrus leaf miner moth is nocturnal and only has a wingspan of 4mm.

Unless you’re out in the garden at night, you’re unlikely to see this adult moth laying its eggs. The moth is mostly white in colour but has some brown markings on its wings.

The larvae of the citrus leaf miner are translucent and greenish-yellow in colour. They are only around 3 mm long.

Because they burrow into the leaves, it’s also quite difficult to spot them.

You can identify an attack of citrus leaf miner by the squiggly silver lines that will appear on the surface of the leaves.

If you see some leaves on your lemon tree that are curled or rolled around the edges, you will most likely be able to spot the pupae inside the leaf. These are pale brown in colour and around 2.5 mm long.

What does leaf miner do to citrus trees?

Phyllocnistis citrella eggs | Pest control
Citrus leaf miner eggs / Photo by Jeffrey W. Lotz / Forestry Images, Wikimedia (cropped) / CC BY 3.0

The tiny larvae of the leaf miner tunnel into the leaf and cause the leaf to distort. Eventually, the trail left by the larvae will turn brown, as this area of the leaf has died.

This will most often occur on fresh, new leaves. Mature leaves are usually not susceptible to attacks from citrus leaf miners.

It’s mostly young trees that will be harmed the most because these usually put on a continuous flush of growth.

If these new leaves are severely damaged, the tree is unable to photosynthesize and this results in stunted growth and a reduction in fruit.

Mature citrus trees are usually not affected severely.

How do you treat citrus leaf miner? 

To treat citrus leaf miner, you have to keep an eye on the new leaves of your citrus tree to see if there are any signs that the pest may be present.

The best way to treat citrus leaf miner is to spray your tree with an oil-based insecticidal spray such as Amgrow Citrus and Fruit Spray.

This will not kill the larvae but will prevent the adult moth from laying more eggs on your tree.

It’s best to spray early in the morning so that you don’t spray any of the beneficial insects such as lacewings and parasitic wasps that will predate on the larvae of the leaf miner.

You can also make up your own solution by mixing up 1 cup of vegetable oil with 1 teaspoon of dishwashing detergent. You then want to mix this with water and spray it on the tree.

To get rid of the larvae, you have to remove all the affected leaves and put them in a plastic bag to throw in the rubbish bin. Don’t put these in the compost.

You will have to inspect the tree every day for any signs of new larvae and continue to remove the affected leaves.

If the infestation is quite severe, you might like to try a product from Yates called Success Ultra Insect Control. This insecticide has an active ingredient called Spinetoram that is absorbed into the leaf and will kill the larvae.

FAQ

What is the citrus leaf miner life cycle?

The adult moth lays its eggs on the young leaves of a citrus tree. Then, the larvae hatch from the eggs and burrow into the leaves leaving silvery lines on the surface. The pupation stage follows where the larvae curl in the edges of the leaves in order to protect themselves until they emerge as adult moths.

What do citrus leaf miner eggs look like?

The eggs are tiny and impossible to see with the naked eye. They look like tiny dew drops and can usually be found on the undersides of the leaves.

Does citrus leaf miner affect the fruit?

It’s quite rare for the citrus leaf miner to infect the fruit. However, the pest may result in a reduction in fruit production in young trees. Mature trees that are more than 4 years old are usually not affected, either in their growth or fruit yields.

Photo of author

Annette Hird

Annette Hird is a gardening expert with many years of experience in a range of gardening related positions. She has an Associate Diploma of Applied Science in Horticulture and has worked in a variety of production nurseries, primarily as a propagator. She has also been responsible for a large homestead garden that included lawn care, fruit trees, roses and many other ornamental plants. More recently, Annette has concentrated on improving the garden landscape of the homes that she has lived in and focused a lot of energy on growing edible plants as well. She now enjoys sharing her experience and knowledge with others by writing articles about all facets of gardening and growing plants.

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