Aphids on citrus trees are more of a problem for younger trees than older trees, because they’re more delicate, with softer leaves. The brown citrus aphids, more commonly known as the black citrus aphids, are one of the most concerning insect pests of citrus plants.Aphids on Citrus Trees

These pests have various negative impacts on trees in the citrus family. Come along as we dig deeper into the terrible effects of aphids on these trees and how to eradicate them completely.

What Are the Causes of Having Aphids on Citrus Trees?

The causes of having aphids on citrus trees are taking up the nutrients of the tree, or due to an infestation of ants; they would feel at ease to infest. Moreover, it can be due to the stressful environment the plant is growing in, and lastly, having grown excessively.

As they begin to infest, you will see the plant is weakening, and this is because of the effects that they start to leave. Some of the effects of aphids on citrus plants like lemon trees include leaf curling, distorted growth, ant activity, reduced yield, disease transmission, reduced photosynthesis, yellowing leaves, and sooty mold.

– Feeding to Take Up the Nutrients

Curling leaves are a common symptom of aphid damage on citrus plants. Lemon tree leaves are usually silky and lush, but things take a bad turn with an aphid infestation. Aphids would begin to feed on the sap in the leaves, gradually depleting them of their nutrients. They inject toxic saliva into plant tissues during their feeding process, causing leaves to curl or deform.

Many times, when you notice your citrus leaves curling, it is most likely a result of an aphid infestation. If you leave them to it, these pests will have all your leaves looking curled or deformed in very little time.

Aphids also cause distorted growth in many citrus plants. This is also directly linked to their feeding action. The tree sap contains essential nutrients the tree needs to grow and survive, so when aphids feed on this sap, they’re essentially depleting these nutrients.

This will cause your trees to lose their vigor, and become distorted or stunted over time. Their feeding action makes it easy for branches and leaves will begin to break off easily and drop, leading to an overall unhealthy plant.Causes of Having Aphids on Citrus

When aphids feed, they suck out the sap from your citrus leaves, gradually depleting their nutrients. This causes the yellowing of leaves, which will even die off if the infestation is left unchecked. Therefore, yellow leaves on your lemon trees may mean you have an aphid infestation, and it is because they absorbed the sap’s nutrients, weakened it, in the long run.

– Having an Ant Infestation

When aphids feed on leaves, they produce a sweet, sticky substance known as honeydew. This honeydew serves as a food source for many other disruptive insects like ants. Ants feed on honeydew, and in turn, they protect aphids from predators, and this way, you would see how one is inviting the other.

This mutually beneficial relationship between aphids and ants allows these citrus pests to survive and spread quickly. Ants climbing and roaming around your citrus plants are a good indication that you might be dealing with an aphid infestation.

While aphids typically don’t feed on citrus fruits like lemons and oranges, their presence and feeding action can prove detrimental to fruit production. If you notice smaller yields, or funny-looking fruits on your trees, the root cause could be aphids, and this is another tell-tale sign of an aphid infestation.

– Stressful Growing Environment

Aphids act as vectors for various citrus diseases, such as citrus tristeza virus and citrus greening. Once they feed on an infected plant and migrate to other plants in a bid to spread and reproduce, they carry these diseases along with them, impacting your healthy plants.

This happens fast, and the diseases will spread quickly because these insects reproduce and multiply very fast. These diseases can cause severe damage to citrus plants, leading to decline, dieback, and even death, and now the aphids would take advantage of the stressed plant, such as having an overwatered plant, as they thrive upon it.

Now, in this state, they begin to absorb the sap from citrus plants and the leaves, which can disrupt the process of photosynthesis. As photosynthesis is important to your plant’s growth and development, this can have terrible effects. Reduced photosynthetic activity usually results in poor growth, diminished foliage, and compromised energy storage, leaving your plants weak and stunted.

Moreover, as they grow more and more, they can weaken citrus plants by sapping their energy and nutrients, which will result in decreased fruit production and smaller-sized fruits. This can significantly impact the economic value of citrus orchards. Besides this, the overall appearance of your fruits will be affected.

– Excessively Grown Tree

When there is a lack of pruning, and cutting off the excessive leaves that the tree is producing, this would become a haven for the pests to grow, develop and hide from their predators. When the tree is growing, and it has leaves that have become yellowed or gotten older, you will see it get stressed, but the pests will love infesting in these old leaves, that they begin to thrive on the fresh and dead leaves.

As the aphids thrive, they would excrete a sugary substance called honeydew as a by-product of feeding. The honeydew accumulates on the leaves and branches of citrus plants, creating a sticky residue.

So, you would notice that this sticky surface can promote the growth of black mold, which can further inhibit photosynthesis and affect the tree’s overall health. Also, the appearance of mold will compromise the healthy looking your plants.

What Are the Solutions To Free The Citrus Trees from Aphids?

The solution to free the citrus tree from aphids is to handpick them and give them the right growing needs. You can use pesticides to tackle, and make sure to free the tree from ants, invite in some beneficial predators, leaves space between each plantation, and prune the tree properly.

Using insecticidal soap sprays is the most effective method of getting rid of aphids on citrus plants. Once you make the spray, ensure to spray your plants thoroughly, making sure to get the top and bottom of the leaves and stems.

Managing aphids on citrus plants typically involves a combination of cultural practices. For instance, you can start maintaining tree health through proper fertilization and irrigation, and biological control methods, like encouraging the presence of beneficial bugs that prey on aphids.

– Handpick Them

Once your citrus leaf curls, there’s no uncurling it. However, you can take steps to get rid of the aphids that are causing it. If you only notice a few of these pests, you can take some time out to hand-pick them from your plants and squash them. The process is slow, but if it is the beginning phase, then this will be helpful and easy.

If you have more than a few aphids on your plants, a blast of water from a hose will work to lodge them off easily. Ensure to repeat the process several times to eliminate all the aphids. You can also trim the affected leaves if only a few exist.

– Give The Tree The Right Needs

If you notice your lemon tree is looking stunted, you need to deal with the aphid problem first, after which you can focus on providing it with adequate growing conditions to restore its vigor. Another way to eliminate aphids is by using chemical control methods. You can use chemical pesticides to get rid of aphids quickly; however, you need to be careful when applying them.

Once the affected leaves are severely damaged, they are unlikely to regain their original color. Still, the plant’s overall health can improve with appropriate treatment, so you can prune them the way you would the infested branches.

Most times, yellow leaves will eventually drop and die, and the tree can focus all its energy on generating new, lush foliage. However, with the right care, you will see the plant thriving as you get rid of the yellowed leaves.Free The Citrus Trees from Aphids

– Use Pesticides

To get the most effective use of these pesticides, spray them at the base of your trees, allowing the roots to absorb them. But for this, you should always choose plant-safe pesticides and ensure you follow the instructions in the letter, to avoid more problems for your plants. Systemic pesticides like dinotefuran and imidacloprid are ideal for ornamental lemon trees, because this way, you will be able to tackle the pests.

– Free From the Ants

Another method to get rid of aphids and other pests like ants is using horticultural oils like neem oil. These oils kill these pests effectively, and once you get rid of the aphids, you will also be effectively getting rid of your ant problem, as they will no longer have a food source on your plants.

You can spray the oil directly on the affected leaves and stems, or rub them directly on the leaves. It’s important to repeat this process until no pests are left on your trees.

– Invite in Some Beneficial Predators

To get rid of the aphids, you can also make use of beneficial insects like wasps, spiders, ladybugs, and lacewings. These insects feed on pests like aphids and quickly devour their entire population.

To attract these natural predators, you can plant flowers or shrubs that attract them around your trees, or simply purchase them from a local garden center. They will have no trouble locating and taking care of your aphid problem.

– Leave Space Between Each Plantation

Good spacing between your plants helps reduce the risk of disease transmission, but not so much, as aphids can jump or fly quite far. Your best bet would be to get rid of them and to avoid their infestation from taking place again, but yet together with this, a way to rid your citrus plants of aphids is by using insecticidal soaps, and this is a natural homemade spray for lemon trees. 

All you need to do is mix a few drops of soap with a lot of water and put it in a spray bottle, to make the application easier. Spray your plants thoroughly, and repeatedly till all of them disappear.

– Prune the Tree Properly

For a start, you can trim off the affected leaves, so you must make sure to use sterilized cutting tools during this process to prevent contamination. After this, you can focus on getting your plants’ leaves back in good health by providing all the necessary care requirements, including light, water, and fertilizers.

This step will help to rejuvenate the sap-depleted leaves so that normal photosynthetic processes can occur. Hence, while a yellow leaf may not turn completely green again, you can focus on promoting your plant’s overall health to encourage the growth of new, healthy leaves.

Once you’ve identified that the cause of your plant leaves yellowing is aphids, you can get rid of them to stop their damage.Using Pesticides on Citrus

At the same time, you may also try to do so as you are getting rid of the affected leaves is best to prevent the mold from spreading. To do this, all you need is sterile pruning shears or any other cutting tool, and plant-safe disinfectant to clean the areas you cut.

You can treat mold-causing aphids by spraying plant-safe pesticides or using any of the other control methods mentioned above. Ultimately, getting rid of the aphids will take care of your mold problem.


It is simple to say that now, you won’t have any more of these pests bothering your prosperous tree, so now, you should know that it’s important to note that:

  • Aphids can cause leaf curling, distorted growth, any activity, disease transmission, mold, and yellow leaves in your citrus plants.
  • Leaf yellowing is rarely reversible, so it’s best to put aphid preventive measures in place before they have a chance to infest your garden.
  • Aphids act as disease vectors, so you would have to use insecticidal soap to kill them.
  • They produce a waste known as honeydew, which ants and several other bugs are attracted to.
  • They are fairly easy to rid of, using biological, natural, or chemical elimination

Now that you can recognize the effects of an aphid infestation and know how best to control them through this article, you shouldn’t have any problems growing your aphid-free citrus garden successfully.

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