Will Aphids Kill Trees?

Trees are often hardy plants that grace our landscapes. But, on occasion, they become susceptible to disease and insect infestations. If you notice this occurrence, you will want to call the arborist at your local tree company to come to assess the issue.

In some instances, we’ll find that the problem your tree is facing is caused by aphids. These are soft-bodied insects often found on the underside of the leaves and are commonly found in trees such as maples as they feed on sap. If you have a severe infestation, you may have called Vernon Imel Tree Service as you noticed the leaves on the tree turning yellow or wilting. But, will aphids kill trees on your property or just make them look diseased?

Will Aphids Kill Trees?Will Aphids Kill Trees - Oregon Tree Removal

A major aphids infestation may look terrible, but it is very likely that they will not cause long-term, detrimental harm to your trees. But, some trees are very sensitive to aphids.

Aphids use their piercing mouth to suck the sap from the tree, ultimately injecting their saliva into the tree and some are very sensitive to this process. This could cause leaves and even flower buds and fruit to look deformed.

You may also be familiar with aphids waste, known as honeydew. This sugar-filled liquid they leave behind is seen as yellow spots you may have noticed on your car if it was parked under an infected tree.

And, if the yellowed or deformed leaves didn’t trigger you to look into your tree, then the fungus that grows in the honeydew may have as it presents as sooty mold, which may be found on lower leaves.

The honeydew or fungus may also draw even more insects to your tree, such as ants, which is why it’s important to address the issue.

How can I care for my trees infested with aphids?

Honestly, the best treatment is prevention, but once you notice aphids, you’re likely already in the midst of a heavy infestation and there are some steps you can take to help your tree heal with haste.

First, try simply washing down your tree with a strong stream of water via your garden hose. Focus on the underside of the leaves, as this is where those little buggers like to reside. Repeat this process daily for up to two weeks until you see your tree is in the clear.

If the infestation needs more oomph to get rid of the critters, try a systemic pesticide. Look for one with an ingredient such as Imidacloprid. This will kill aphids once ingested, but will not harm good garden bugs like bees and butterflies.

Another option is summer oils, which kills the aphids by suffocation. Fatty acid salts and insecticidal soaps can also be effective in killing the bugs by disrupting its cell membrane. Other insecticides like malathion, chlorpyrifos, and acephate are all options as well. Any of these applications will likely require reapplication to be successful.

The issue with any application is that it must reach the aphids and since they live on lower branches of the tree, they are protected by foliage and may not be directly penetrated by the pesticide, rendering it useless.

Similarly, the tree may be too tall for you to reach the aphids and commercial application can be expensive and results may vary.

If prevention is key, what are those recommendations?

There are a number of steps you can take to prevent aphids from infecting your trees, even if a past infestation has already taken place.

If a few aphids are located, one option is removal via pruning. But, these pests reproduce very quickly, so control measures are necessary after they are located on just 5% of your tree.

So, your first step is to regularly inspect your trees for any developing issues, as it’s much easy to rid them of just a few of the bugs before they cause much damage.

Another option is to select neighboring plants that aphids dislike. These include oregano, chive, sage, leeks, garlic, and onions as the bugs are deterred by the strong scents. Or, plant aphid-attracting plants, like calendula, on the opposite side of your property to draw them away from your beloved trees.

You may also want to attract aphid-eating bugs that can benefit your landscape like lady beetles and lacewings. Add in plants that attract these bugs nearby and you’re less likely to deal with aphids in the future.

If you noticed aphids on your fruit tree this past season, you can add horticulture oils during the winter in hopes of killing any eggs that may be primed to attack your tree once spring returns.

Also, take a look at the fertilizer you are using, if any. Aphids are attracted to trees high in nitrogen, so if your fertilizer contains this element, switch to one that offers slow release.

Aphids are a pain to prevent and destroy, but will aphids kill trees? It’s unlikely. They’ll just create more work for you to care for their health each season.

If you think you may have an aphid infestation, these are recommended tips to control and prevent their presence, but your first step should be a call to your local arborist, like our team at Vernon Imel Tree Service.

Like any tree issue, you should take the time to confirm what problem your tree is facing before you start treatment as the incorrect steps may be more detrimental than the initial problem that arose.

Our arborists have extensive experience and are certified to address any issue your trees are dealing with and we’ll make sure the necessary protocols are put in place to ensure your tree is vibrant and lush once again.

Are you concerned you may have an aphid issue? Reach out to our team today. We can’t want to help you help your trees.