So, you have pests on your acer trees. AKA Japanese maple.
In this article, we’ll cover:
- Common bugs on Japanese maple
- Natural ways to get rid of acer pests
- How to keep bugs off your acer trees
- And more.
You should have a solid foundation of how to control, manage, and exterminate acer tree bugs by the end of this page.
Sound good? Let’s save your Japanese maple from pests.
What’s an acer tree?
It’s important to know that you’re dealing with the right tree first before you attempt to get rid to do the pests.
For those who are unsure what kind tree they have, acer trees are also called Japanese maples and are a deciduous shrub (small tree) that reaches 20-33 feet.
They’re found in shady woodlands and have multiple trunks joining together at the ground.
They usually have a dome formation when established.
Each leaf is about 3-12 cm and wide with a lengthy structure.
There are an odd number of lobs, usually 5, 7, or 9 on each end. The flowers are usually purple and white with a fruit. The fruit is called samara and comes in pairs of two.
There are many different species of acer trees.
There are a few other names for this popular tree.
Acer trees are also called:
- Japanese maple
- Palmate maple
- Smooth japanese maple
- Red emperor maple
- Acer palmatum
- Acer amoenum
- Acer Matsumura
Now that you know the tree you have and can confirm if you have an acer tree, we can move on to the actual pest ID to see what’s eating your Japanese maple tree.
What bugs eat Japanese maples?
There are a few common pests that’ll eat acer trees.
The ones that most people seem to have trouble with are the following:
- Mites (spider mites, round mites, etc.)
We’ll take a look at each of them and cover how to get rid of them from your Japanese maple.
There are many home remedies you can do to control, exterminate, and prevent bugs from getting onto your acer tree.
Thankfully, you can most likely save your tree by just being persistent and trying a few of them out and seeing what works for you.
Common pests on acers
Here are some of the most common Japanese maple insects that you’ll be dealing with and how to get rid of them.
The key is to try a few of them out and see what works best for you. Then scale up that technique.
Maple tree insects vary in what can control them. No single solution can be a “one size fits all” fix.
Aphids are a common pest that will eat up your acer trees like no other.
These small bugs will quickly multiply into a pest nightmare for your maple tree.
Not only do they extract your acer tree’s nutrients, they also can cover your leaves and turn them into nests sprawling with these bugs. If you’ve never seen a severe aphid infestation, you probably don’t want to.
Because Japanese maples are expansive trees with their protruding foliage, aphids will spread from one branch to the next.
Who wants to go outdoors and see a ton of leaves crawling with aphids?
Aphids come in many different colors and species. The most common ones you’ll see on acer trees are green and yellow. Black aphids are also common. Aphid damage shows up as curled or discolored leaves.
They may also become distorted or warped and eventually fall off the tree. You also may catch a few of them on the leaves near the tree trunk.
Note that if you see small, black, wingless pests, these are also likely aphids.
Not dangerous, but unsightly
They rarely can kill an acer tree, but they can severely damage the tree and also make it unsightly.
They are commonly found on the tips of maple trees and will leave behind a sticky residue. Aphids aren’t really that hard to control, but they come back during the springtime as that’s when they hatch.
Other pests like scales or ants will usually follow wherever the aphids go as they’re after the honeydew and the same environment.
Scales produce their own soot but prefer the same environment as aphids. Ants are just attracted to the frass and sweet residue aphids create.
How do I get rid of aphids on my Acers?
Aphids aren’t really that difficult to get rid of.
They don’t do much damage to Japanese maple because of their small size.
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But if you have a ton of them, their efforts to feast on your acer will multiply. Not to mention the ants they attract.
Aphids can be controlled by purging the infected trees to quickly reduce their numbers and eliminate nymphs.
You can also use DIY pesticides, such as soapy water (8 drops dish detergent and 1 cup water).
Use Simple Green
Another common solution to aphids on maples is to use Simple Green, which is a popular non-toxic cleaner found in department stores. Most plants will react positively to Simple Green, but that doesn’t mean all will.
Always test on a small part first before applying to the whole maple. You can spray every day for a week and make sure you hit all the aphid areas.
You should avoid using any oil-based pesticides for maple trees, as this will burn up new growth of leaflets.
Liquids that are oily or greasy should be avoided to protect your tree. Some solutions like essential oils can be safe to use if diluted enough.
Ladybugs are prominent predators of aphids and will help eat up the aphids.
They’re very effective and will clean up your aphid problem faster than you think. If you don’t have native ladybugs, you can buy live ones at select nurseries or online.
The ladybugs need to be “applied” to the tree. Once all the aphids on your acers are gone, they migrate and leave. Use them as directed by the supplier.
Caterpillars will eat any seedling or mature leaf.
They’re not picky eaters and acer trees are no exception. The larvae form of butterflies, caterpillars seek out easy to digest plant matter and this usually is plant seedlings.
They can severely harm acer trees if ignored. Caterpillars usually come in swarms as the adults lay dozens of eggs simultaneously. The adult butterfly won’t harm maple trees.
But the larvae form does.
There are a few different techniques you can use to control and get rid of caterpillars on your Japanese maple.
Add plants near your maple tree that repel caterpillars. This may help prevent them from migrating from one tree to another.
Set up the plants around each tree as a natural barrier to block caterpillar migration. They fall off leaves and trees all the time.
And if they try to crawl to a neighboring acer, the repelling plants that caterpillars hate deters them permanently.
Use protected gloves and remove caterpillars by hand.
Dunk them into a container filled with warm water and dish detergent. This will kill them. Repeat this “purge” early morning or at night with a flashlight as caterpillars are nocturnal.
You can also check out my detailed caterpillar removal guide.
Mites are tiny bugs that have a rounded shape and appear as miniature spiders.
They are a known pest of acer trees and will feast on them all day.
There are also many different types of these 8-legged bugs that destroy Japanese maple trees. Spider mites are no joke and many plants are susceptible to them.
They pierce the leaves and suck nutrients from them. This will cause damage over time and the leaves often become turned.
Don’t let them take over your tree.
Red spider mites on your Japanese maple will deteriorate the plant by acting like vampires and extracting all these nutrients.
They appear as tiny specks that move around on the leaves and are difficult to see.
Most spider mites can’t kill an entire acer tree as they simply can’t do the damage but they can leave your acer very strained from resources.
The damage they cause is destructive and disgusting to look at.
Your leaves turn brown and may fall off. The overall appearance will be a dim coloration that changes from green to brown.
You may also notice bronze leaves or pale yellow, shrunken leaves.
Roud mites only eat maple leaves that are still developing. They’re rarely found on Japanese maple, but some readers state they’ve seen this pest.
The mites rapidly reproduce and eat new leaves by forming galls. The leaves curl up. They’re most commonly found on red maple trees and only attack trees that are still developing.
If you think you have gall mites, but your acer is already matured, you probably have spider mites. These may appear as tiny black bugs on your acer tree.
But for those who believe so, here what to do.
Gall mites are relatively harmless to acer trees. They may slightly injure established trees and leaves, but for most mature acers, gall mites can’t do much damage.
The reason? Because gall mites don’t eat no-growing trees
They need foliage that’s not already matured. They only eat growing plant matter, which means new leaves or Japanese maple that’s not yet matured.
As soon as your plant stops growing leaves, the gall mites disappear.
Ants on Japanese maple
Ants will herd aphids to the end of the maple branches.
They’re commonly discovered with aphids as they go hand-in-hand.
Aphids produce poop and the ants eat it. The honeydew that aphids make tends to lure more ants to the tree.
This is because the honeydew is sweet and molds, which ants will feast on.
Once you have aphids, ants are also likely to show up because they eat the aphid frass and the honeydew.
Sometimes the ants are seen eating the aphids also. You should avoid using any commercial sprays, as this will harm the beneficial bugs.
Focus on natural repellents and ant killers such as soapy water or some kind of essential oil. These work against ants and aphids naturally.
How do you get rid of maple gall mites?
For younger trees, this is a problem and you can use the following home remedies to get rid of them.
Gall mites can be contained by pruning the infested leaves manually. This will dramatically reduce their population and kill them off.
You’ll also want to use a natural spray to kill them. Gall mites overwinter during the cold season.
You can use liquid lime sulfur and spray your tree to reduce the number of overwintering mites. This will help minimize their next generation that emerges in the spring.
Apply the life sulfur in temperatures above 40F and when no freezing conditions are expected. If you think temperatures may drop, hold off on applying it.
Gall mites are eaten by lacewings and ladybugs. If you have these predators native to your yard, do some research and find out how to attract them to your yard.
You can, for example, plant flowers that attract ladybugs or create a lacewing-friendly backyard. These predators eat gall mites and will help control the population.
Lastly, if you want to use a commercial approach, get some pesticide that has diazinon to kill gall mites.
Use as directed. avoid when possible and use organic or natural control.
Worms are also a destructive pest just like caterpillars. Worms are usually the larvae form of moths and flies.
Carpenter worms are the main culprit that you’ll find on acer trees. These worms are borers, meaning they can chew through the wooden trunk of your maple.
This can lead to the quick destruction of the maple, especially young ones. Larger, matured maple trees are resistant to worms, but these pests can still chew through branches.
You’ll often find branches that fall off or snap easily during high wind or over time.
They bore through the nutrient-dense areas which weakens the overall structure of the tree and damage the branches.
Carpenter worm damage is noticeable because they’ll leave behind clumps of sawdust.
They eat through the branches and leaves of new trees and leave behind sawdust accumulation on the soil and within their bores.
They may also scar the branches and trunk of your acer maple. This is why you need to always be cautious and watch out for any signs of borers.
They’re difficult to control since they dig holes into your tree.
What is eating the bark on my Japanese maple?
Some common Japanese maple insects that eat the bark are carpenter worms as they’re a borer that eats their way into branches and bark.
If you notice sawdust or holes in your tree trunk, the tree is probably infested with carpenter worms.
These are hard to control as with any wood-boring pest.
Maple scales are small bugs that appear as whitish cotton.
They’re easily confused with mealybugs, as they both produce a white fuzz on the plant.
However, scales have no segmented heads or bodies, so they look like tiny circular pests that move around.
They have piercing mouths that they use to penetrate the plant and suck up precious nutrients. This will make your acer leave start to wilt and discolor over time.
The leaves eventually drop off the tree.
You’ll see that they’ve been curled and you’ll see scale covered on the underside.
How to get rid of acer scale
Scales are difficult to control especially on larger trees like Japanese maple.
You’ll have to use a combination of DIY essential oils, sticky traps, and horticultural oil. You can also use a garden hose to blast them off on a daily basis- twice per day.
There are also predators that eat scales such as predatory beetles and parasitic wasps. If you have these predators native to your area, research how to attract more of them to your yard and help eat the Japanese maple sale.
Scale can be controlled by a spray only when they’re still nymphs.
Once they develop their exoskeleton shell, sprays are useless. If you need to resort to pesticides that are store-bought, seek out systemic ones.
These sprays are usually not as destructive to beneficial bugs and also keep scales off your acer. Use the spray as directed as most of them do contain toxic residues.
However, if you need to resort to using a commercial solution, you can consider a systemic one. There are systemic that you mix in a watering can and there are granules that are slow release.
Honeydew on Japanese maple
The majority of acer bugs leave behind sooty substances called honeydew on plants.
Scale, mites, and mealybugs all produce this cottony, white fuzzy stuff which you’ll find on your acer leaves, especially younger ones.
What can I spray on my Japanese maple for bugs?
You can spray many different types of DIY pesticides and store-bought brands, but you should always avoid using oil-based poisons.
As mentioned earlier, there are a few homemade sprays you can use to kill aphids, scale, ants, and other pests on your acer trees.
Just mix 1 teaspoon of dish detergent to 1 cup of water. Then combine into a spray bottle and spray directly onto the pests.
The detergent traps pests and drowns. Dish soap isn’t natural, but most are safe for plants. You can use something like Dawn or even an all-natural one.
This popular household cleaner is safe for most acer trees and kills ants, aphids, and mealybugs.
Just spritz your leaves and branches daily for a week and see what happens. As with any spray, test it on a small portion of your tree first.
Simple Green is non-toxic and safe for humans, but that doesn’t mean you should overdo it. Less is more. Spraying too much of this stuff may harm your Japanese maple.
How to save your acer tree
The best way to save your Japanese maple from pests is to get rid of them.
As obvious as it sounds, you should start a treatment plant right away as soon as you notice plant damage or pests.
You’ll want to find out what bug is eating your leaves and how to get rid of it.
The most common pests are covered above in this article, so check to see if you’re dealing with any of those pests. Then follow the steps to handle them and save your tree.
If you don’t notice any bugs at first, continue monitoring for signs of bugs on your acer tree:
- Black or curled leaves
- Wilted leaves
- Falling leaves
- Visible white stuff (fuzz) on your leaves or branches
- Damaged trunks
- Holes in the branches or trunk
- Visible tiny flies, specs, or pests
Note that your tree could be unhealthy just because of the conditions it’s currently in.
These trees require specific care and basic TLC that you should already be familiar with.
But if you don’t remember or need a refresher, here are the basics for acer care:
- Use only well-draining soil
- Offer partial shade
- Use fertilizer during the summer
- Be sure to keep your plant well-pruned on a weekly basis
That’s about it. These trees don’t require much to care for and are noted as pretty and hardy plants. If you need more help, here’s a handy resource.
But If you think the problem your tree is dying is because of pests, then you’ll want to apply the methods outlined in this guide.
How to get rid of bugs on acer trees
Here are some DIY remedies you can try out on your Japanese maple trees.
See what works best for your pest situation. Other than using the methods already listed above, these are some additional ones.
You should find the bug you’re dealing with and read the steps to exterminate it. Check the appropriate section.
Use a hose
Spraying down your acer tree with a pressurized stream of water will rid many of the bugs.
Aphids and ants have poor grip under a water stream and this can be a quick way to get them off your tree.
While it doesn’t necessarily get rid of them permanently, the water disturbs their environment.
- For aphids, they lose track of their colony and nest. Aphids feed in large groups and when they’re forced to scatter, this alters their environment.
- For ants, they rely on pheromone trails and running water will mess up their scent-driven pathing.
Hosing is also fast and efficient, as you just need to spray your acer tree twice a day- once in the morning and once again at night after the sun disappears.
This provides sufficient coverage for both morning and nighttime pests and covers the tree in water to discourage bugs. Think of it as population control.
Remove pests by hand
While removing the bugs by hand may not be the most appealing option, it definitely can be effective.
Depending on the size of your Japanese maple, you may be able to remove many of the pests using a scraper.
Paint scrapers or putty scrapers work well and can be used to literally scrape off dozens of bugs at once. You can use it on aphids, ants, and even mealybug or scale fuzz.
Put on a pair of garden gloves and get a container filled with soapy water or rubbing alcohol. Then scrape off any pests you see and dunk them into the container to instantly kill them.
Dispose of the water safely after you’re done.
You can repeat this daily or every other day and you’ll notice how quickly the bugs on your acer tree disappear.
Prune your tree
Pruning is another quick removal method because simply taking off branches or leaves that are infested or unhealthy is efficient.
Remove entire branches that you notice a lot of pest activity and dunk them into a solution of rubbing alcohol.
This is a quick and natural way to eliminate pests on your Japanese maple quickly because all it takes is a snip for younger plants.
The tree will grow back slowly provided it has the resources to do so. But it also allows the energy to focus on new branches or existing ones that are currently healthy and not destroyed by bugs.
Vacuum bugs up
You can use a small shop vac or standing vacuum with a hose attachment to suck up aphids and ants.
If your vacuum is powerful enough, you may be able to suck up the mealybug or scale deposits. This will rapidly remove pests without harming your acer tree.
How to keep bugs off Japanese maple trees
Here are some methods to keep pests away from your acer tree. Always stick with 100% natural methods when possible.
Use a residual solution
Some sprays can be used that leave behind a residual effect so you don’t have to constantly reapply it.
This is useful to prevent bugs from coming back to your acer tree because it naturally repels them and keeps them away.
There are some DIY mixtures you can use, such as neem oil and water or a variety of essential oils. Lavender oil, citrus oil, clove oil, and peppermint oil all work well.
The only problem is to make you dilute it enough so the oil doesn’t burn the tree leaves. This will require some testing to make it work.
Try a ratio of 2 drops per liter of water at first. If your tree takes it without issue, then you can bump up the drops. Oils work well, but they can suffocate the tree if not dosed correctly.
So be careful with any type of oil-based remedies, whether it’s DIY or store-bought.
If you really have to, you can use a store-bought brand to help you control the pests. Get something that’s all-natural or organic. Use as directed.
You can plant companion plants nearby your acres to reduce the number of pests in the area.
There are a few plants that will naturally repel aphids, ants, scales, and mealybugs.
You should check the hardiness zones of these plants and see if they’re able to grow in your yard:
Anything that has partial shade and requires rich acidic soils with deep watering during the summer months should do well.
Some of these plants also have pest-repellent properties which can help deter some bugs from your acer trees.
Here are some references you may find useful:
- Scale Insect Control – GardenForum Horticulture
- Maple (Acer)-Cottony maple scale – PNW Handbooks
- Scale Bug attack on Acer – UBC Botanical Garden Forums
Did you get rid of the bugs on your acer tree?
By now, you should have a solid foundation to start exterminating the common pests that you’ll encounter on a maple tree.
You should be able to handle aphids, ants, scale, and mealybugs with a decent success rate and confidence!
There isn’t much to ti other than patience and persistence while using the RIGHT control method.
That’s why it’s important to try out a bunch and see what works on your tree- not just one or two and give up.
If you have questions, post ‘em below and I’ll try to assist. Or if you found this page helpful, tell a friend =]!
Thanks for reading.
Currently an active researcher in the pest control industry for the past 8 years- with a focus on using natural and organic methods to eliminate pest problems.
I share handy DIY pest techniques I come across here to help out others (and possibly save them from a mental breakdown).
Fight nature with nature.