What Problems Do Asian Longhorn Beetles Cause?

A lot of hue and cry has been made over the spread of the Asian Longhorn Beetles in the US in recent years, and in this article, we will tell you exactly why they are so dangerous.

Could you ever think that a small beetle is capable enough of toppling down massive healthy trees? Yes, it is true.

The Asian longhorn beetles are known for their ability to destroy backyard trees by boring continuous network tunnels through the bark.

In this article, we will take a closer look at these insects and the extent of damage they are capable of inflicting. It will share details on how to control these pests.

What Is the Asian Long-Horned Beetle?

The Asian longhorn beetle, also scientifically known as Anoplophora glabripennis, is a member of the vast beetles family that poses a significant threat to a wide range of healthy trees.

These beetles are majorly found in China and neighboring countries. The adult beetles have a glossy black body with an irregular network of white spots on them.

They have 0.75 to 1.25 inches long bodies (this excludes the length of the antennae).

The Asian longhorn beetle larvae feed on the wood of trees by boring tunnels in the trunk of healthy living trees.

How Do Asian Longhorn Beetles Kill Trees?

The adult female beetles lay eggs on chewed depressions that they create in various hardwood trees.

Once these eggs hatch, the beetle larva starts tunneling across the bark of the tree. They create tunnels through different layers of the trees to consume wood.

These larvae spend nearly two to three years inside the host tree.

After constant chewing and tunneling, the larvae reach the woody tissue of the healthy tree and continue to feed on the same, making the tree nearly hollow from the inside.

When the larvae emerge from the tree, they leave behind large gaps of 3/8inch diameter, which allows tree sap to flow from them.

This makes it worse for the poor tree since it weakens it structurally and makes it susceptible to other diseases and pests.

In some cases, the trees become so structurally weak that a strong gust of wind can knock them over.

What Problems Do Asian Longhorn Beetles Cause

Which Trees Does it Target?

These beetles often select trees where they can complete their entire lifecycle without having to change their hosts.

In the US, they choose hardwood trees like mountain ashes, sugar maple, chestnut, willow, and more. All of these are economically important trees.

In China, Korea, and other Asian countries, it has infested trees like poplars and mulberries.

What is The Asian Longhorned Beetle’s Damage To the Economy?

We already mentioned that the Asian longhorn beetle could cause significant economic losses.

But how are they capable of doing so? When these insects occupy trees near the street, there is a high chance that these trees might fall at any given point due to a lack of strength.

Thus, they must be removed immediately, and proper treatment must be given to eradicate these insects from the region.

The cost of repairing and replacing the street trees and clearing the ALB population from the area is almost $100 per infested tree.

If these pests enter a forest range, the economic damage can be far more significant.

A complete infestation of these beetles in a well-grown forest of hardwood trees can heavily impact the export market for almost all hardwood products.

Thus, these insects can cause a loss of billions of dollars if they are not stopped. Adding to that, the cost of containment and eradication will also be high.

Asian Longhorned Beetle or Not???

Where Has This Beetle Spread in the US?

The longhorn beetle was first discovered in New York City and Chicago. Here they were spotted destroying ornamental trees.

Since then, regular detections of these insects have been made in the northeastern part of the United States.

It is conjectured that these bugs entered the US via untreated wooden crates and packaging material from China.

What Can Be Done To Control It?

These pests have some natural enemies, like the woodpecker and red wood ants, but external measures must be taken to eradicate them.

People often use pathogens to kill the populations of these beetles.

The fungus Beauveria bassiana can kill these insects when injected into newly dug holes made in trees. Brongniartii is also exceptional in infecting and killing these adult beetles and their larvae.

Apart from such parasites, entomopathogenic nematodes are also used to get rid of these insects. The S. feltiae nematode is effective in killing these wood-boring beetles.

Lastly, as of now, the method being used is to completely eradicate the trees and surrounding trees that are infested so as to limit the spread.

Frequently Asked Questions

How does the Asian longhorned beetle impact the environment?

The Asian longhorned beetle highly affects the environment by killing healthy trees of maple, elm, chestnut, willow, mulberry, and more but boring deep tunnels.
This pest has the tendency to destroy shade-giving trees and can also damage an entire forest range that contains trees of high economic value.
Therefore great efforts are taken to eradicate their population completely and ensure that they do not enter our hardwood forests.

How does the Asian longhorned beetle affect biodiversity?

The Asian longhorn beetles are known to destroy a wide range of trees.

The infestation can highly reduce the biodiversity in a forest and alter the population of tree species. Therefore constant external measures are taken to get rid of these Asian longhorn beetles.

Can longhorn beetles fly?

Yes, the longhorn beetles are capable of flying for distances, but they generally cover short distances.
These longhorn beetles are capable of flying and covering up to 8.5 miles, though on average, they travel about 1.4-miles.
Fortunately, these bugs are not very fond of flying and prefer to spend their entire lives inside their host trees.

Do longhorn beetles eat houses?

The longhorn beetles usually do not usually enter houses. They may enter only from the untreated wood brought into the house.
These beetles may come indoors, creating a nuisance, but surprisingly they don’t infest cured lumber that is used to build furniture, nor dried firewood.

Wrap Up

The Asian longhorn beetles are a big threat to biodiversity and the growing species of trees across major forest ranges.

Therefore it is essential to know how to control them and eradicate their populations if you spot an infestation near you. We hope this article will help you with that.

Thank you for reading the article.

Reader Emails

Ever since Asian Longhorned beetles gained their notoriety in the US, many of our readers have been checking in with us to see if they have sighted one in their garden or yard.

Here are a few such emails.

Letter 1 – Asian Longhorned Borer or Starry Night Sky Beetle


can you identify this bug?
Hey Bugman,
I was surfing the web and happened upon your website and thought it was pretty cool. The thing is I’m working in Seoul, South Korea right now and a few months back I came across this big bug that I’d never seen before. I took a picture of it with my cell phone and I’ve been wondering ever since. I’ve never been able to identify it. Can you help me out.
PS – again, it was a cell phone camera, so the picture quality is pretty mediocre.

Hi Ian,
Your beetle, the Asian Longhorned Borer, Anoplophora glabripennis, is a new exotic introduction to the U.S. and it is causing quite a bit of commotion. The U.S. Department of Agriculture site states: ” This beetle is a serious pest in China where it kills hardwood trees in roadside plantings, shelterbelts, and plantations. In the United States the beetle prefers maple species ( Acer spp.), including boxelder, Norway, red, silver, and sugar maples . Other known hosts are alders, birches, elms, horsechestnut, poplars, and willows . A complete list of host trees in the United States has not been determined. Currently, the only effective means to eliminate ALB is to remove infested trees and destroy them by chipping or burning. To prevent further spread of the insect, quarantines are established to avoid transporting infested trees and branches from the area. Early detection of infestations and rapid treatment response are crucial to successful eradication of the beetle. ” According to another government site, the English translations from Asian languages for this beetle’s name include Starry Night Sky Beetle and Sky Ox Beetle.

Letter 2 – Mating Asian Longhorn Beetles


Asian longhorned beetle love
Love you site, check out the attached Anoplophora glabripennis shot.

Mating Asian Longhorns
Mating Asian Longhorns

Hi Mike,
We are thrilled to have your wonderful documentation of mating Asian Longhorn Beetles, especially since it will be cross referenced in our Bug Love section and our Invasive Exotic section of our new site, which we are currently about to migrate to, however, your photo lacks a location. Was this taken in native China? or is this an example of the species spread in North America? As this species has become established in the U.S., there is much information about the species online, including this UC Davis posting.

Worcester, Massachusetts.

Letter 3 – Longhorned Borer Beetle emerges from Firewood


Bugs coming from firewood?
January 17, 2010
I’m finding these bugs in our house and they seem to be coming from our firewood. We do keep some wood in the house for use and have a couple of racks outside our house.
Eastern Pennsylvania

Longhorned Borer Beetle

Hi Bill,
Our eyes are crossed from clicking through all the pages of BugGuide’s Cerambycidae section to no avail.  We had hoped to identify the species, but the best we can do is the family Cerambycidae, the Longhorned Borer Beetles.  We will see if Eric Eaton can provide a species identification.  Firewood brought indoors often causes dormant wood boring insects to emerge due to the warmth indoors.

Longhorned Borer Beetle

Eric Eaton provides an identification
Hi, Daniel:
The actual beetle specimens are longhorned woodborers, Phymatoes varius in all likelihood.  There are no images of this species on Bugguide currently, so we would welcome the person to submit them there.  We also have some top-notch cerambycid experts who could confirm or correct my own ID.

Hi Daniel & Eric,
I’d be happy to post the images, however I don’t know how. If you would like to post them, feel free to do so. Is there any problem with finding these insects in our home? I wanted to make sure they weren’t termites, which may be a problem.
Thanks for your help,

The adult insects are not interested in wood as that is the larval food.  Borers do not infest milled lumber, though there is occasionally a possibility of the larvae surviving the milling process and then emerging from furniture or structural beams many years later.  That is a rare occurrence.

Letter 4 – Tan Bark Borer may have emerged from firewood


Subject: beetle
Location: northern wisconsin
February 26, 2013 12:05 pm
We have been seeing these insects inside the house for the last several weeks, perhaps one or two a day. We don’t remember seeing them in the house prior to this winter. They started appearing after our first significant snowfall of the winter. They can appear anywhere in the house and are very slow moving, rarely flying.
Signature: Bob and Martha

Longhorned Borer Beetle
Longhorned Borer Beetle

Dear Bob and Martha,
Do you burn firewood in the home?  We suspect you brought in some wood and these Longhorned Borer Beetles had been living in the wood as wood boring larvae, and that they were most likely in the pupa stage when the heat of the home caused them to emerge early.  We are pressed for time this morning, and cannot browse through the family Cerambycidae on BugGuide to identify the species.  Perhaps while we are at our regular job, one of our readers will supply a comment with an identification.  We will try to determine a species at a later date.

Update:  February 27, 2013
Thanks to a comment identifying this as a Tan Bark Borer, Phymatodes testaceus, we are investigating on BugGuide
.  It appears we might be getting confused with Martha.  According to BugGuide, the Tan Bark Borer is:  “native to Eurasia; widely established around the world, incl. e. US and, more recently, in the Pacific Northwest”

Thanks for the tip – we do burn firewood and Martha suspected that that might be the source of the beetle.  From the photos on your site, we think that it is an oxycopis thoracica
Bob and Martha

Well, on further review it appears to be Phymatodes testaceus, which makes more sense given it’s oak firewood origin.
Thanks again,
Bob and Martha

Hi again Bob and Martha,
When we received a comment that this was a Tan Bark Borer, we turned to BugGuide.  We saw your submission that “Martha thinks they are coming from the firewood” and we suspected that we were being confused with Martha Stewart.

Letter 5 – Longhorned Borer collected in 1984 is not native to North America!!!


Subject: Asian Longhorn beetle??
Location: Tulsa Oklahoma
September 28, 2013 10:03 am
In 1984 when I was taking entomology I captured this bug along the Arkansas river walk in Tulsa Oklahoma. I always just assumed it was an Asian Longhorn beetle, so I never double checked myself…but now while doing some more research I am seeing that the Asian Longhorn beetle seems to be more ”spotted” rather than striped. The specimen is 2 1/8 inch long from top of head to end of abdomen, so quite a large beetle. Did I misidentify this guy? He’s still in my collection, so I’d love to correct any mistake I may have made.
Signature: BugLady

Longicorn is Batocera species

Dear BugLady,
First we want to commend you on preserving your insect collection for nearly 30 years.  We just lamented that a collector who captured a lovely Carolina Tiger Beetle would most likely discard it after receiving a grade.  This is not an Asian Longhorn, but the family Cerambycidae is correct.  We will attempt to get you a species identification.

Hi Mr. Marlos,
Not only have I preserver my collection, it has been the foundation of my business…started three years ago.
It’s a long story, but I have been fascinated by insects since the age of 8. I mainly studied Lepidoptera mimicry in graduate school…and I gave my collection a glance now and then…The beetle I caught while biking along the Tulsa River Walk  on the way to school, and he always gave me pause, because I assumed identification and never verified it…..
(I had to bike back to my college apartment one handed, while holding this guy…and he scratched the * %^% out of my hand.)
I respect everything I mounted and I have had my collection museum crated and moved at great expense when I moved cross country. It is the center of my living room wall now…
I am always saddened by the people that tell me they had a collection and then discarded it…I think life, even insects, deserve respect, and we need to use it to teach future generations about the beauty and diversity of nature and the need to preserve and protect the world around us.

Eric Eaton Responds
Hi, Daniel:
Well, it is certainly not a species native to the U.S.  My best guess is Batocera wallacei, or at least something in the genus Batocera.  Sometimes insects like this sneak in on commerce from other parts of the world, but….
I’m copying my reply to Ted MacRae, who knows far more about longhorn beetles than I do.  Hopefully he will weigh in, too.

Hi again BugLady,
It appears we owe you an apology.  While your beetle is not THE Asian Longhorn,
Anoplophora glabripennis, that has gained such notoriety in recent years (see Asian Longhorned Beetle website), it is AN Asian Longhorn.  We are awaiting additional input from Ted MacRae.  While this is a non-native species, we don’t have any indication that it was able to reproduce in Oklahoma, so it is most likely not an invasive species, however we are nonetheless tagging it as an Invasive Exotic species. 

Ted MacRae provides his expertise
Hi Daniel,
Eric is right, it is a species of Batocera, a genus native to Africa and southeast Asia.
It is common for large, exotic longhorned beetles to be captured emerging from furniture or pallets once in the U.S., but it is another thing to find one out in the wild – especially one as large and spectacular as Batocera. I’d need some convincing that this doesn’t represent merely a mislabeled specimen.
Best regards,

Editor’s Note:  Cold Case
Since so much time has elapsed, it is likely we will never know for sure how this African/Asian Longicorn found its way to the Arkansas River in Tulsa, Oklahoma.  Perhaps the river was used to transport goods brought from Asia.  A warehouse nearby might have housed the goods that included crating or palettes that contained the pupa that eventually emerged and was captured by BugLady.  This is all speculation of course.

Hi Daniel,
Her story seems to be valid – the part about biking back home one-handed while the beetle clawed her other hand convinced me.
I’m just glad this species apparently never established in the U.S., but it is quite extraordinary that it made it all the way into the middle of the country and was then found by somebody with an interest in insects.
Best regards,

Very Interesting…and somewhat exciting! I always meant to get a positive ID on this one…just never got around to it until now…
The specimen was definitely captured by me in 1984. It has been in my collection ever since and nothing has been switched or mislabeled. It is actually the only large longhorn in that collection and I did not collect non-native species until well into 2000.
The River Walk in Tulsa Oklahoma runs along the Arkansas river. There is a port in Catoosa Oklahoma. Maybe it came in on a shipment…or maybe there is a breeding population that just has not been recorded yet…How many entomologists are looking for beetles along that area?

Editor’s Note
We requested permission to use BugLady’s real name and to provide a link to her business.

Not at all…It would  great!
On another note…please realize that in the early 1980s the internet was not what it is today…(also I was not a computer person), so although it is easy to find help with Insect identification now, back then websites like yours did not exist, and even though I checked a few books and nothing really matched this specimen so I labeled it “Asian Longhorn Beetle” and then went along my way…but I have always wanted to get a positive ID, so I thank you for your help with that!
Katja Hilton
Amazing & Beautiful Butterflies

4 thoughts on “What Problems Do Asian Longhorn Beetles Cause?”

  1. Along with the Emerald, Ash Borer Asian Long-horned beetles are an invasive species brought to America on ships. Large populattions in New York and New Jersey.

  2. Along with the Emerald, Ash Borer Asian Long-horned beetles are an invasive species brought to America on ships. Large populations in New York and New Jersey.

    • Thanks Arianna,
      We will take a look and update the posting. We needed to get out of the (home)office and to our real job, and it is so nice to return with a possible identification.


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