Are Longhorn Beetles Dangerous? Some of Them Are

Longhorn beetles are denizens of trees and spend their entire lives boring tunnels through them, making them hollow. But are longhorn beetles dangerous? In this article, we will talk about them in more detail.

Have you observed pencil-like holes in the bark of several trees near your home?

Or you might have noticed that the leaves of backyard trees suddenly start yellowing despite the season being spring.

These are the signs that longhorn beetles have infested the tree. These beetles can destroy trees by tunneling inside them and making them nearly hollow.

In this article, we will discuss longhorn beetles and how dangerous they are.

Are Longhorn Beetles Dangerous

What Are They?

There are many species of longhorn beetles scattered across the world. The beetles can vary in size. An average longhorn beetle can grow from 0.25 to 3 inches long.

They have dark brown or black bodies with white spots on them.

When adult beetles lay eggs, they do it in freshly cut trees. Their larvae emerge from eggs and burrow into the tree bark for food. They create tunnels in the wood and live there for more than 2-3 years

The longhorn beetle larvae are white to yellowish in color and have a worm-like shape.

Longhorn beetles are known to perform a pivotal role in the decomposition and nutrient-cycling process in forest regions.

These beetles are known to consume living organisms and dead organisms; in some cases, they even consume dying organisms.

Are These Bugs Dangerous to Humans?

These beetles usually do not enter human houses, but they can sometimes come in from freshly cut pieces of wood brought indoors.

These beetles pose no threat to humans as they rarely show any aggressive behavior towards humans.

You will be relieved to know that they also cannot attack the furniture or damage the household properties. However, they will crawl around the house, creating a nuisance.

Are They Poisonous?

These beetles don’t have a venomous sting and are not poisonous to human beings. The only real threat is that they can damage trees.

Moreover, longhorn beetles are rarely seen attacking humans or pets. However, they will attack if you try to manhandle them, and their bites can cause severe pain.

Do Longhorn Beetles Bite?

These beetles are known to eat both living and dead organisms. They attack both old and healthy trees to eat wood.

Adult Asian Long-horned beetles (Anoplophora glabripennis) are herbivorous and usually feast on leaves, twigs, and other plant matter.

They are known to cause damage worth billions of dollars due to their penchant for eating through trees like poplar trees, elm trees, and so on.

They rarely sting or bite humans or pets, but they will bite if you mishandle them. The bite can cause a blister on your skin. Therefore one must be careful around them.

What Damage Can They Do?

Asian Longhorn Beetles, one of the insects from this family of beetles, can cause massive damage to trees.

In some cases, they are responsible for completely destroying big healthy trees.

These beetles are especially attracted to mountain ash trees, maple trees, willow trees, and more.

The larvae of the beetles grow inside these trees and spend one to three-years tunneling through them, eating the wood.

This makes the tree hollow, and even a strong gust of wind can knock an entire beetle-infested tree.

Long-Jawed Longhorn Beetle

Symptoms of an Infestation?

If an Asian longhorn beetle has occupied a tree near your house, you might see some of these creatures loitering around your yard or house.

However, these beetles are usually hard to track and get rid of. Here are a few common signs that will help you detect a longhorn beetle infestation:

  • You might notice some chewed-up round depressions in the bark of the tree.
  • Pencil-sized round exit holes in the tree are another indication.
  • There might be a high amount of sawdust gathered around the base of the tree.
  • Non-seasonal yellowing and shedding of leaves.

Frequently Asked Questions

How do I get rid of longhorn beetles in my house?

Follow the methods given below to get rid of longhorn beetles from your house:
Identify the beetle’s areas and drill some injection holes in them.
Remove the dust from these holes and carefully fill them up with some timber injection gel.
Doing this will help you to cap off these holes. The beetles will not be able to survive if their exit holes are closed. It will help in the successful eradication of these beetles.

Why are there longhorn beetles in my house?

One of the biggest reasons for beetle infestations in homes is the excessive moisture content in wooden structures and furniture.
Therefore to avoid this, you must make sure that your house has no leaking roofs, plumbing problems, or water-leaking corners.
Also, these beetles are highly attracted to willow and maple trees. Having a few of them near your house might be another reason.

Do longhorn beetles fly?

Yes, adult longhorn beetles can fly in search of food or a mate. These beetles can fly up to 400 yards.
But, they are mostly seen in and around the tree they are infesting, making internal tunnels through the bark of the tree.
The Asian longhorn beetles can fly but for short distances.

Do chirping longhorn beetles bite?

Chirping longhorn beetles usually do not attack or bite humans, but if they feel threatened, they will bite.
The bites are highly painful and can cause a blister in the wounded area. Apart from that, they usually refrain from biting humans and feed on firewood and timber with high moisture content.

Are black and yellow longhorn beetles poisonous?

The black and yellow longhorn beetle is a wasp mimic that uses its color and striations on the body to convince predators that it has a poisonous sting.
However, from whatever information is available, this type of beetle is not poisonous or venomous in itself and does not have a stinger either.

Wrap Up

The longhorn beetles are ecologically significant creatures.

Despite their ability to completely destroy healthy trees, it is claimed that their presence ensures a healthy nutrient cycle throughout a forest.

Dealing with these insects can be difficult, but we hope after reading this article, you will be able to identify them and take measures to stop their damage.

Thank you for reading the piece. 

Reader Emails

Several readers have shared with us pics of longhorned beetles to identify these rather funny-looking creatures over the years.

Please sample the wid variety of longhorned beetles from our reader’s archives below.

Letter 1 – Puerto Rican Long Horned Beetle: two foreign mystery bugs

 

What an excellent and fun website! I thought you might be able to help me with two mystery bugs that have proven baffling. The second is this strange bug my entomology class in Puerto Rico. We were stuck, and I still am – I can’t place it to order even, although the mouthparts and thorax might suggest some weird orthopteran. This specimen was about 2 and a half cm from antennae-tip to the base of wings.
Thanks!
Robbie

Hi Robbie,
Thanks for the photos of the exotica. They are a mystery to us as well. Your Puerto Rican Orthopteran looks according to Eric Eaton, to be probably a longhorned beetle (Cerambycidae).

Ed. Note: We just received the following correction.
(08/09/2005) identifications Hello – I was recently shown your site, and it is excellent. My specialization is longhorned beetles, and in cruising around I notice a number of incomplete or uncertain IDs for this family. I don’t know if you are interested in receiving this sort of input, but if you are, I offer the following additions to your identifications.
This is a species of Bebelis, probably lignosa, or perhaps schwarzi; no species is specifically recorded from Puerto Rico, but several my occur there. The larvae typically bore in small stems of semi-woody plants (sunflower, ragweed, etc.) Cheers.
Frank Hovore

Letter 2 – Aristobia approximator: Longhorn Borer Beetle from Malasia

 

Could not identify this bug anywhere on the internet.
Hi, I’m Jason Lai from Malaysia and I need some of your help to identify this bug. I caught it in Fraiser’s Hill, Malaysia for an insect collection project and its due next thurs (25/1/2007). hope you can identify the bug by then. thx!
Jason

Hi Jason,
This is Aristobia approximator, one of the Longhorned Borer Beetles in the family Cerambycidae. We found this identification in a wonderful book we were given entitled Living Jewels by Poul Beckmann printed by Prestel. We then did some web searching with the name and discovered this beetle has appeared on stamps from Laos in 1974, North Vietnam in 1977 and Central Africa in 1962. It can also be found for sale to insect collectors on many sites.

Letter 3 – Longhorn Borer Beetle from India

 

colourful bug in india
hi bug man,
told you i had more, mostly cos i don’t know the first thing about identifying bugs.
anyway in found this little guy in india in my room in Trivandrum. night time not very active didn’t move even after a substantial amount of shooting. was the only one of its kind i have ever seen and i do look. February 2008.
esthar2001@yahoo.com
Trivandrum, India

Longhorned Borer Beetle
Longhorned Borer Beetle: 

Hi esthar2001@yahoo.com
This is a Longhorn Borer Beetle in the family Cerambycidae. Sorry we can’t be more specific than the family.

Hi esthar2001@yahoo.com. Most longhorn beetles (Cerambycidae) are fairly drab so I thought yours would be relatively easy to track down – not so. I suspect that your beetle is either uncommon or hasn’t made itself and agricultural or forestry pest. I took several approaches and all trails seemed to lead to the genus Batocera (sufamily Lamiinae). This genus includes several notorious pests, perhaps most notably the mango stem-borer (Batocera rufomaculata), which is a serious problem in India and many other parts of south Asia. The genus also includes a number of species with brilliant red markings. I was able to find one internet site that featured a Batocera sp. that looks very similar to yours at: http://albumo.com/photo/212955/Longhorn-Beetle—Batocera-sp..html. The photos are from Malaysia, but many Asian species are quite widespread. I suspect this may be a closely related species. Cheers. K

Correction courtesy of Karl:  December 4, 2016
Hi Daniel and rastaPoPoy:
It looks like this longicorn and the one from your archives are indeed the same species. Although I previously suggested that it might be a species of Batocera, it seems I was on the wrong track. In checking again I am now going to suggest that this lovely beetle is Olenecamptus bilobus (Cerambycidae: Lamiinae: Dorcaschematini). The species is widely distributed throughout Asia and Melanesia, and comes in a variety of colour variations. Two  subspecies occur in India; O. bilobus bilobus and O. bilobus indianus. The two subspecies are quite similar and your two postings could belong to either one. Here are some additional images from Assam and the Seychelles.  Regards  Karl

Letter 4 – Banded Hickory Borer from Oklahoma

 

another unknown longhorn not on wtb!
Sun, Mar 8, 2009 at 7:18 PM
Hi,
I found this little guy in our pool on Friday, and have found several others since then. I haven’t seen these before, and I have no idea what kind of longhorn they are. I searched through all your longhorn pages and couldn’t find them. They are about 1 ½ inches long, and are light grey with two light brown marks on their wings. They were found in central Oklahoma. I appreciate any help you can provide.
Josh Kouri

Unknown Longhorn Beetle
Banded Hickory Borer

Hi Josh,
We want to format all three of your photos for posting and we don’t recognize your Longhorn Borer Beetle. We hope Eric Eaton or another reader can supply an answer that may take us considerable time to research, so we are posting it as unidentified.

Longhorn Beetle
Banded Hickory Borer

As with many male Longhorn Borer Beetles or Longicorns, your specimen displays some mighty impressive antennae. The photo of your beetle about to take flight nicely illustrates how the hardened elytra are positioned when the soft flying wings are needed.

 

Longhorn Beetle

Update: Hi, Daniel:
The lovely longhorned beetle is a male “banded hickory borer,” Knulliana cincta.  We actually have a subspecies of that beetle emerging in Arizona right now!  I didn’t know they came out this early.  I got some in Missouri when I lived there, but seem to recall it was later in the year….They are not a destructive species.
Eric

Letter 5 – Long Jawed Longhorn Beetle

 

Orange and Black Bug
Tue, Jul 7, 2009 at 10:13 AM
We were enjoying a 4th of July BBQ in Cave Creek, AZ when this guy decided to join us. Right after I snapped the picture on my iPhone (attached) he flew away. His body was about an inch long. Can you help me figure out what kind of bug this is?
Desert Knight’s Ranch
Cave Creek, AZ

Long Jawed Longhorn Beetle
Long Jawed Longhorn Beetle

This really is an attractive Cerambycid or Longhorned Borer Beetle.  We searched on BugGuide until we properly identified it as a Long Jawed Longhorn Beetle, Trachyderes mandibularis.  It is found from Texas to California and south to Guatemala.  Also, according to BugGuide, “Males have particularly long mandibles” which would indicate that perhaps your beetle is a female.  It seems that females of the Long Jawed Longhorn Beetle have antennae nearly as long as those of the males.

Letter 6 – Longhorn Beetle from China: Batocera rubus

 

Chinese beetle
November 10, 2009
Hello,
I saw these on a (low) hill path in Zhongshan in China yesterday and wondered what they are? Is it mother and child or a male/female couple? Thanks
Neil
Zhongshan city, GuangDong, CHina

Chinese Longhorn Beetles
Chinese Longhorn Beetles

Hi Neil,
The markings on your beetles are different than those on examples of Mango Stem Borers, Batocera rufomaculata, that we have posted previously, but there are enough similarities for us to question if this is perhaps a regional variation.  Your beetles might be a closely related species in the genus Batocera, like perhaps Batocera davidis, or perhaps a member of another genus in the Long Horned Borer family Cerambycidae.  In our opinion, this is a couple.  Perhaps one of our readers can assist in this identification.

Update from Karl
Hi Daniel:
They are definitely a Batocera species (Cerambycidae: Lamiinae: Batocerini) but not B. rufomaculata. There are several similar looking species in Asia, but as far as I can tell only B. davidis and B. rubus occur in China. The B. davidis photo that you linked to does look very much like the ones in Neil’s photo, but most images of B. davidis do not show the prominent white spots on the elytra. This could be an example of regional variation, or it could be another case of misidentified photos on the web. On the other hand, there are numerous postings of B. rubus and they all appear very similar. For comparison, the ‘Siam Insect-Zoo & Museum’ site has excellent photos and descriptions of all the species mentioned here. I think I have to go with B. rubus. Coincidentally, I also came across a photo of mating B. rubus (subspecies mniszechi) from the Philippines that is remarkably similar to the one posted by Neil. Regards.
Karl

Letter 7 – Golden-Bloomed Grey Longhorn Beetle from UK

 

LONGHORN BEETLE ??
June 6, 2010
LONGHORN BEETLE ??
I cannot find a picture exactly like this after a long search – is this british?
Possibly more than an inch long, on cow parsley, active = hard to focus camera, extremely pretty – what is it and should it really be here?
Sue Climpson
RG28 7SX, Whitchurch Hampshire UK

Golden-Bloomed Grey Longhorn Beetle

Hi Sue,
First we need to say that we understand your frustration at not being able to find this Golden-Bloomed Grey Longhorn Beetle, Agapanthia villosoviridescens, in your online searching.  We began our search by typing the family and location, Cerambycidae and UK, and we were immediately led to the ideal website for the search, bioimages.org.uk, but alas, we could not figure out how to access the images of the insects that were recorded in UK.  By all indications, this should be an easy task, but we kept encountering obstacles.  Undaunted, be began to copy and paste the names indicated on the website in a new browser window and searching with the information provided.  Finally, we landed on the Golden-Bloomed Grey Longhorn Beetle page of Bioimages and though we still do not know how to access the images on that site, the name led us to a wealth of other sites with matching images of your beetle, beginning with Wikimedia Commons.  The NatureSpot website indicates:  “Mainly found in moist meadows and hedgerows.  Adults feed on umbellifers such as Hogweed and Cow Parsley as well as on Nettles
” and “A stem borer that breeds in the stems of thistles and other herbaceous plants.”  Though we were quite frustrated with the very user unfriendly BioImages website, we are thankful for the list it provided for our search.

Letter 8 – Longhorned Borer Beetle: Graphisurus fasciatus

 

Female Longhorn Beetle
July 14, 2010
Hi Daniel,
This lady made her way into my living room last night. I put her up for the night so I could get some photos. I think I have mached her to an image on Bug Guide http://bugguide.net/node/view/126701 if this correct it is a Cerambycidae Beetle – Graphisurus fasciatus. Never saw a common name (which I prefer) The number of insects living around me is amazing and I never took the time to look before now. Thank You and have a wonderful day.
Richard
North Middle Tennessee

Longhorned Borer Beetle

Hi Richard,
We believe you have correctly identified this Longhorned Borer Beetle without a common name,
Graphisurus fasciatus, based on images posted to BugGuide.  We also love the graphic look of your photograph.

Letter 9 – Black Longhorned Borer Beetle from Colorado

 

Beetle on my dead tree
Location: Aurora, Colorado
June 6, 2011 1:49 pm
I have a tree that just recently died and it’s got bore holes all over it which is why I assume it died. I’ve attached two photos of some beetles I found on the tree. I can’t tell if they’re what are boring the holes or if they’re just hanging out as I havent been able to find any tennants in the holes.
Signature: Mike

Unknown Borer

Dear Mike,
This is a member of the Longhorned Borer Beetle family Cerambycidae, known as the Bycids for short.  The larvae bore in the wood of trees and shrubs and most species are very host specific.  While some species do considerable damage to living, healthy trees, many members of the family will only infest trees that are already compromised by disease or stress.  What species of tree is this?  The bark resembles a Eucalyptus, but we want to know for certain.  We don’t recognize the beetle, but those enlarged hind femora are a good identifying feature.  We haven’t the time to identify this species at the moment, but you can try browsing through the possibilities on BugGuide.  We already spent about ten minutes searching with no luck.  We will also try to contact Eric Eaton to see if he recognizes this species.

Eric Eaton Responds
Daniel:
Something in the genus Callidium.  Should be several species in Colorado.  Here’s more:
http://bugguide.net/node/view/42797/bgpage
Have fun in Colorado!
Eric

Thanks Eric,
This image on BugGuide is nearly identical.

Letter 10 – Longhorned Borer Beetle from Domican Republic

 

What kind of beetle
Location: Cabrera, Dominican Republic
October 6, 2011 2:19 pm
We were visited by this beetle during our recent trip to Cabrera, Dominican Republic. He/she spent a few days up there watching the festivities. He/she was a bit over 3” long. The locals said they call it a crunchy beetle because of the noise it makes when the step on em.
Signature: OregonJac

Longhorned Borer Beetle

Dear OregonJac,
This is a Longhorned Borer Beetle in the family Cerambycidae.  We would further classify it as a Root Borer in the subfamily Prioninae.  We found a video on YouTube of the largest beetle in the Dominican Republic called
Xixuthrus domingoensis, but its mandibles are smaller.  Perhaps you have the male of the species and the larger female has smaller mandibles though we are not convinced they are the same species.

Ed. NOte:  We found this in our draft box and we are not certain why it was never posted nearly two years ago.

Letter 11 – Flower Longhorn Beetle: Strophiona laeta

 

Subject: Longhorned borer
Location: Silverton, OR
August 21, 2012 4:33 am
This one has been bugging me (no pun intended)
I know it’s a longhorn beetle and by the size of the antennae and colors I would say it looks like a Neoclytus caprea or a Typocerus velutinus but the pattern and coloration are quite different. I live in Oregon and caught him by blacklight. Hopefully you can give me a positive id.
Signature: Jesse

Longhorned Borer Beetle:  Strophiona laeta

Hi Jesse,
Your photos are beautiful.  Do you have a straight dorsal view?
We will research this and get back to you.

Longhorned Borer Beetle:  Strophiona laeta

Thanks, this is a little personal project i’ve been doing.  This snapshot is as close to the view as i have. I turn on a couple backlights by my house every night and see what lands on my window. I live adjacent to an white oak grove if that helps narrow it down at all. I have never scene this type before so i was kind of excited.
-Jesse

Flower Longhorn Beetle:  Strophiona laeta

Hi again Jesse,
Thanks for sending the dorsal view.  This is a gorgeous Longhorned Borer Beetle and we don’t believe it will be too difficult to identify, but it might take some time.  We just returned from a long day at work and we are preparing the posting and tagging it as unidentified while we do the research.  We hope to have an answer for you shortly.

Hi again Jesse,
We believe we have correctly identified your gorgeous Longhorned Borer Beetle as
Stenostrophia tribalteata.  There are several subspecies profiled on BugGuide and the species ranges from California to western Canada.

WTB? contacts Doug Yanega
Hi Doug,
I believe I have correctly identified this beauty as Stenostrophia tribalteata.  The specimen was attracted to a black light in Silverton, northern Oregon at the edge of a white oak grove.  Now I am beginning to doubt the ID I made because no photos show the yellow underbelly and the pubescence that appears on the ventral surface as well as the thoracic region.  Can you confirm or correct and possibly narrow to subspecies?   Also, any thoughts on black lights to attract Cerambycids?
Thanks for any possible information.
Daniel

Ed. Note:  Another possiblity
Moments after reaching out to entomologist Doug Yanega, we believe we might have identified the correct species as
Strophiona tigrina, which appears to be a much better match according to images posted to BugGuide.  The data for the range on bugGuide is also a match.  Again, there is no specific information on BugGuide and the banding pattern is not exactly the same as the individual on the Natural History of Orange County website.  Strophiona laeta, which BugGuide reports from California might be the best match.

Doug Yanega confirms Strophiona laeta.
That’s correct.

Letter 12 – Longhorned Borer Beetle from Dominican Republic is Callipogon sericeum

 

Subject: Is this a CALLIPOGON ?
Location: Jarabacoa, Dominican Republic.
November 11, 2012 8:36 am
This giant bug, about 4” long was found this morning in Jarabacoa. Dominican Republic.
Can you please help me identify it?
Signature: Mario Davalos

Callipogon sericeum

Dear Mario,
We know we have seen images of this beetle or a close relative previously, however, we are having problems identifying it, so we decided to post your image prior to an identification.  We do not believe it is in the genus
Callipogon, though we do believe it is in the same subfamily, Prioninae.  We checked several websites with no luck, including Coleop-Terra and the Worldwide Cerambycoidea Photo Gallery where the closest match we could find are the members of the genus Macrodontia. We did not think a beetle this distinctive would be so difficult to identify.  We are going to contact Eric Eaton for assistance.

Thank you.  I’ll await news. Hopefully we’ll be able to identify it.
Regards
Mario

Hi again Mario,
It seems you were correct with the
Callipogon identification.  Our loyal reader and frequent contributor Cesar Crash from Brazil has provided the name Callipogon sericeum as the species and the Harvard Collection of Caribbean Insects has fourteen images of mounted specimens from the collection.  We also found a matching photo on the Cerambycidae of Cuba website despite our original search of those key words coming up blank.  Perhaps not all males have such well developed mandibles, or perhaps some of the images posted online are actually of different species.  At any rate, all indications are that this species is a rarity that is commanding very high prices on online auctions of individuals nowhere near as impressive as the individual in your photograph.  Congratulations on a gorgeous photograph of a living specimen, especially since we cannot seem to find any other examples of living males with such developed mandibles anywhere online.

Letter 13 – Female Longhorn Borer Beetle

 

Subject: what is this
Location: tinton falls,nj
June 10, 2015 6:58 am
I think this bug flew inside, found in my monmouth county, tinton falls nj next to the woods apartment.
Moves quickly walking, possibly flies
As its still its long and narrow
Not sure if that’s a stinger?
Please help!!
Signature: -P

Graphisurus fasciatus
Graphisurus fasciatus

Dear P,
This is a Longhorned Borer Beetle in the family Cerambycidae, and what you have mistaken for a stinger is the ovipositor, and organ that is used by the female when laying eggs.  We did a web search using the key words “Cerambycidae, ovipositor, New Jersey” and we were led to Green Art and an image of
Graphisurus fasciatus and the information that it:  “is well camouflaged when moving about on tree bark. The best way to find it is near lights in the night. The larvae are boring into hardwood. Note the large ovipositor of the females.”  We verified the identification on BugGuide.

Letter 14 – Antlike Longhorn Beetle from New Zealand

 

Subject: Ant’s
Location: Central North Island, New Zealand
October 26, 2015 8:20 pm
I found this in my garden today, its is about 4mm in body length and dark blue with these two yellow spots
Signature: Mike

Longhorn Beetle
Longhorn Beetle

Dear Mike,
Though it resembles an Ant, this is actually a Longhorn Beetle in the family Cerambycidae.  Several years ago we posted an image of a mating pair that were identified as being in the genus
Zorion.  there are many nice images on the GrahamNZ website and there is also a nice image on FlickR

Thank you for the information.  I phoned someone who should have known and was told by him it was a flower bug
At least I know its basically harmless.  It will now go in the files with the spiney spiders found last year
Mike

Hi again Mike,
In defense of your source, we do have a comment on our previous posting indicating this is a Flower Longhorn, however our research, including a scholarly article on the Massey University of New Zealand site, has determined that it is in the subfamily Cerambycinae, not Lepturinae whose members are commonly called Flower Longhorns according to BugGuide.

 

Letter 15 – Longhorned Borer Beetle from Arizona is Megacyllene antennata

 

Subject: What is this fascinating critter?
Location: Gold Canyon, AZ
February 25, 2016 5:46 pm
Wandered into our camp in Gold Canyon, AZ. Anyone know what this is?
Signature: Deirdre

Longhorned Borer Beetle
Longhorned Borer Beetle:  Megacyllene antennata

Dear Deirdre,
This is a Longhorned Borer Beetle in the family Cerambycidae, and we need additional time to determine its identity.  We have written to Eric Eaton for assistance.

Eric Eaton Responds
Daniel:
Yes, it is Megacyllene antennata.  Here’s a link:
http://bugguide.net/node/view/29440
Thanks for sharing!
Eric

Ed. Note:
According to BugGuide, the food plants for the southwestern species are:  “mesquite and (catclaw?)”

Letter 16 – Long-Jawed Longhorn Beetle

 

Subject: Orange striped beetle?
Location: Tombstone AZ
August 9, 2017 1:23 pm
What is this bug?
Signature: Terri

Long-Jawed Longhorn Beetle

Dear Terri,
This gorgeous Longicorn,
Trachyderes mandibularis, is commonly called a Long-Jawed Longhorn Beetle.  According to Texas Entomology:  “There are 16 species of Trachyderes (in two subgenera), but only T. m. mandibularis reaches the United States.”

Letter 17 – Ant-Mimic Longhorn Borer Beetle

 

Subject:  Beautiful beetle
Geographic location of the bug:  Central Ohio
Date: 05/07/2019
Time: 07:09 PM EDT
Your letter to the bugman:  Found this gorgeous beetle on my arm.  May 7th 2019.  In a lightly wooded area with nearby stream. At first I thought it was an ant, but the antenna look like a beetle.  The texture of the abdomen is like a blister beetle.
How you want your letter signed:  Jennifer Huffman

Ant Mimic Longhorn Borer Beetle

Dear Jennifer,
We were impressed with how much this Longhorned Borer Beetle in the family Cerambycidae resembled an Ant, so we researched that and located this image of
Cyrtophorus verrucosus on BugGuide.  According to BugGuide:  “Ant mimic. Distinctive markings, and note also knobs at base of pronotum” and “Adults take nectar and/or pollen on spring-flowering trees and shrubs.  Larvae feed on a wide variety of hardwoods, including Acer, Betula, Carya, Castanea, Cercis, Cornus, Fagus, Quercus, Ulmus, & Pinus.

Ant Mimic Longhorned Borer Beetle

Wow super cool!   I won’t tell you how many long horned beetles I looked at late last night trying in vain to find something like this.  Too bad I couldn’t get better pictures, maybe I should have chilled him too!
Thanks so much for the fascinating info and for saving my sanity.
Jennifer

Hi Jennifer,
BugGuide does indicate:  “A remarkable ant mimic, this species runs like an ant.”

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Letter 1 – Round Headed Apple Tree Borer

 

Subject:  What’s that bug? Geographic location of the bug:  Miramichi, NB Date: 09/03/2017 Time: 04:59 PM EDT This little flew away after I tried several times to get it off my hand by trying to put it on a flower but it just didn’t want to let go! How you want your letter signed:  Linda Burns
Round Headed Apple Tree Borer
Dear Linda, This Round Headed Apple Tree Borer makes such a magnificent Buggy Accessory, we can’t imagine why you would ever want it to leave your hand.  We haven’t tagged a Buggy Accessory in a few years.  According to BugGuide:  “Larvae feed on the wood of apples (Malus) and related trees in the rose family, such as pear (Pyrus), hawthorn (Crataegus), mountain ash (Sorbus) and Saskatoon (Amelanchier). Also: Aronia, Cotoneaster, Cydonia, Prunus. Adults feed on leaves” and “These insects seek out trees which are already weakened due to some other stress. A heavy infestation can kill a tree.”

Letter 2 – Round-Headed Borer Larva

 

Subject:  Wood borer in finished hardwood floor. Geographic location of the bug:  Brant County near Grand River & Brantford. ON Date: 11/18/2017 Time: 10:25 AM EDT Per attached pictures, grub was located by blowing out fine white sawdust from 3.25″ long bore hole and injecting wasp an hornet foam insecticide into the hole to the depth of the hole. The grub moved to the entrance and was removed. The hole was discovered when the surface of the floor sank and in probing the very thin wood and varnish were lost. Further slivers were raised in probing the hole. Can you identify the species? How you want your letter signed:  Gord Burkholder
Round-Headed Borer
Dear Gord, Unfortunately, the image of the Round-Headed Borer is considerably less well focused than the image of the wood damage, but even if the image was better quality, we would most likely not be able to provide more than a family identification.  Round-Headed Borers are the larvae of Longicorn Beetles in the family Cerambycidae, and knowing the host plant might be helpful.  What we can tell you is that the larva was most likely already in the wood when the tree was cut, though sometimes the beetles will lay eggs in freshly cut logs.  We can state with relative certainty that the larva was already in the wood by the time the lumber was milled.  Longicorns do not infest milled lumber, so you do not need to worry about further damage, unless there were other larvae in the wood prior to milling.  Do you know the type of hardwood and the location where the trees were grown?  That might help with a more definite identification.  We have heard of incidents when adult beetles will emerge from lumber milled many years in the past.  You might find interesting information on the Nature.com article entitled “Identification of wood-boring beetles (Cermabycidae and Buprestidae) intercepted in trade-associated solid wood packaging material suing DNA barcoding and morphology” where it states:  “Global trade has created a pathway by which nonnative species may cross once impervious natural borders such as oceans and mountains.”  That site acknowledges “The larvae depicted are visually similar and are difficult to identify below the family level. “ 
Wood Damage
Thank you Daniel;
I should have added more info. The floor has been down almost 8 years and the oak came from Quebec. There have been no other indications of other infestation. Part of the house heating is done by a wood stove and I have some concern that the species may have been introduced from the firewood.
Regards;
Gord Burkholder
Hi again Gord, We are relatively confident this individual was in the wood at the time of milling and not introduced from firewood.

Letter 3 – Poplar Borer from Canada

 

Subject:  Found this in my yard last summer Geographic location of the bug:  Sherwood Park, Alberta Date: 02/18/2018 Time: 11:13 PM EDT Your letter to the bugman:  This was really big. What is it? How you want your letter signed:  Hi
Poplar Borer
Based on this BugGuide image, we are pretty confident that your Longicorn is a Poplar Borer, Saperda calcarata, and it is described on BugGuide as being:  “Largest of its genus. Prominent spines at tips of elytra. Coloration variable, pastel hues.” 

Letter 4 – Unidentified Longicorn from Borneo is Thysia wallichii

 

Subject:  Longhorned Beetle Geographic location of the bug:  Kinabalu Park, Borneo Date: 07/01/2018 Time: 05:26 PM EDT Your letter to the bugman:  Spotted this beetle in the grounds of our hotel in Kinabalu Park.  While it is obviously a Longhorned Beetle, I’ve not managed to find anything quite like it on the net.  Can you identify it please? How you want your letter signed:  Pete Rowland
Longicorn:  Thysia wallichii
Dear Pete, Our initial search did not produce a species identification for you.  The tufted antennae on your individual are distinctive and other Longicorns, including Batus barbicornis pictured on Insect Collective share that trait.
Longicorn
Update:  Both Cesar Crash and Karl wrote in to identify Thysia wallichii which is pictured on Cerambycoidea.com, Jungle Dragon and on FlickR.

Letter 5 – Musk Beetle from Ireland

 

Subject:  Chameleon bug Geographic location of the bug:  Glenbeigh Co Kerry Ireland Date: 08/08/2018 Time: 12:02 PM EDT Your letter to the bugman:  Please identify this strange creature. How you want your letter signed:  Brian
Musk Beetle
Dear Brian, We are not entirely certain why you are calling this Musk Beetle, Aromia moschata, a “Chameleon bug” but we can roll with that.  According to Eakring Birds:  “This is a huge beetle, probably the largest species found in Nottinghamshire. … this is a scarce beetle in Nottinghamshire anyway, and it’s stronghold may possibly be along the Trent and Idle Valleys. Named after it’s ability to produce a pleasant smell, Aromia moschata is a beetle that can also produce an audible sound when handled. It’s also one of the Longhorn Beetles and frankly, has no comparison in size with any others.”  According to the IUCN Red List of Threatened Species:  “European regional assessment: listed as Least Concern in view of its wide distribution, presumed large overall population, it occurs in a number of protected areas, has a tolerance of a degree of habitat modification, and because it is unlikely to be declining fast enough to qualify for listing in a more threatened category.”  The site goes on to list the following countries where the Musk Beetle is reported, a list that includes Ireland:  “Austria; Belarus; Belgium; Bosnia and Herzegovina; Bulgaria; Croatia; Czech Republic; Denmark; Estonia; Finland; France (Corsica, France (mainland)); Germany; Greece (Greece (mainland)); Hungary; Ireland; Italy (Italy (mainland), Sicilia); Latvia; Liechtenstein; Lithuania; Luxembourg; Macedonia, the former Yugoslav Republic of; Moldova; Montenegro; Netherlands; Norway; Poland; Portugal (Azores, Portugal (mainland)); Romania; Russian Federation (Central European Russia, East European Russia, European Russia, Kaliningrad, North European Russia, Northwest European Russia, South European Russia); Serbia (Kosovo, Serbia); Slovakia; Slovenia; Spain (Spain (mainland)); Sweden; Switzerland; Turkey (Turkey-in-Europe); Ukraine (Krym, Ukraine (main part)); United Kingdom (Great Britain, Northern Ireland)” 
Musk Beetle
Thank you! Chameleon because it seemed to change colours. Maybe it was the way the light was shining on it. Thanks, Brian It does appear to have a purple to green sheen in the images we have seen.

Letter 6 – Wasp Beetle from the UK

 

Subject:  Black and yellow striped insect Geographic location of the bug:  South Wales UK Date: 05/26/2019 Time: 12:48 PM EDT Your letter to the bugman:  Found this insect on my patio table in late may. Don’t know wether it relevant but we had just taken a large tree down.  Never seen one before.  It definitely jumps as it jumped straight at me.  Didn’t appear to be making any sounds.  Legs were definitely more of a red orangey colour.  What bug is this? How you want your letter signed:  Yvonne the gardener
Wasp Beetle
Dear Yvonne the gardener, Because it is such an effective mimic, this Longicorn in the family Cerambycidae, Clytus arietis is commonly called a Wasp Beetle.  According to Nature Spot:  “It breeds in the decaying wood of deciduous trees. It can often be found in clear view, resting on leaves in low vegetation. Presumably its yellow and black colours warn off any predatory birds!”

Letter 7 – Unknown Longicorn from South Korea

 

Subject:  Beetle Geographic location of the bug:  South Korea Date: 06/27/2019 Time: 04:25 PM EDT Your letter to the bugman:  Hello Please can you tell me what kind of beetle this is? Thank you. How you want your letter signed:  Paul
Longicorn
Dear Paul, This is a Longicorn or Longhorned Borer Beetle in the family Cerambycidae, but we have not had any luck identifying the species.  Larvae of beetles in this family are wood borers.
Longicorn
Longicorn

Letter 8 – CORRECTION: Neoptychodes trilineatus, not Round Headed Apple Borer

 

Subject:  invasive Longhorn beetle or native? Geographic location of the bug:  South Texas Date: 08/26/2019 Time: 12:42 AM EDT Your letter to the bugman:  Found this beetle and i was wondering what kind is it and if it is native of Texas How you want your letter signed:  Gabe
Flat Faced Longhorn is Neoptychodes trilineatus
Hi Gabe, Your images are quite artful.  This is a Round Headed Apple Borer, a native to North America.  According to the Michigan State University Integrated Pest Management System:  “Attack apples mainly, but most deciduous tree fruits are susceptible. The larvae dig tunnels, most often at the base of the tree trunk. The roundheaded borer leaves accumulations of reddish frass at the entrance of galleries. Infested trees have a sickly appearance, producing sparse, pale-colored foliage (C). Continued yearly attacks can kill the tree or weaken it so that it is broken off by the wind. Young trees that have been girdled will often bloom profusely and set a heavy crop of fruit and then die in the process of bringing it to maturity.”
Neoptychodes trilineatus
Correction: Neoptychodes trilineatus We just received a comment from Brady Richards correcting this misidentification.  According to BugGuide:  “Although Ficus is the primary host, larvae also develop in Alnus, Morus, Salix, Celtis. ”
Neoptychodes trilineatus

Letter 9 – Purplescent Longhorn: Purpuricenus humeralis

 

Subject:  What is this? Geographic location of the bug:  Winnipeg Manitoba Canada Date: 06/26/2021 Time: 03:32 PM EDT Your letter to the bugman:  Noticed on my golf bag on the golf course. June 25,2021 How you want your letter signed:  Dave S.
Purpuricenus humeralis
Dear Dave, Though this Longicorn superficially resembles both the Red Shouldered Pine Borer and the Elderberry Longhorn Desmocerus aureipennis, it is a species of Purplescent Longhorn, Purpuricenus humeralis, with no common name that we found on BugGuide.  Interestingly, in doing the research for your posting, we found Purpuricenus humeralis incorrectly identified as a Red Shouldered Pine Borer twice on our site, here and here, and we have made the necessary  corrections.

Letter 10 – Musk Beetle from the UK

 

Subject:  Large green bug Geographic location of the bug:  Stretham near Ely Date: 07/23/2021 Time: 07:49 AM EDT Your letter to the bugman:  This large green flying bug landed on me yesterday. Its body was 30-35mm long and it had long curved antenna which do not show up too well on the photo.  Searched on Google to no avail. Could you please identify for me? Any info much appreciated How you want your letter signed:  John
Musk Beetle
Dear John, This Longhorned Borer Beetle in the family Cerambycidae is commonly called a Musk Beetle, because according to Eakring Birds:  “This is a huge beetle, probably the largest species found in Nottinghamshire. It’s large size struck us when we found this adult on a Sallow trunk in Gamston Wood near Retford in July 2010 and more recently in June 2011 (top two photographs). On the day, we also saw a second beetle alight near the top of another Sallow in the adjacent Eaton Wood. These are believed to be the first site records, but this is a scarce beetle in Nottinghamshire anyway, and it’s stronghold may possibly be along the Trent and Idle Valleys. Named after it’s ability to produce a pleasant smell, Aromia moschata is a beetle that can also produce an audible sound when handled.”   The species is also pictured on FlickR.
Dear Daniel
Thanks for your speedy reply! I did not realise we had such a bug in the UK quite an eye opener! I have bought your book on Kindle so hope this will help me with future identifications. Good hunting!
Best regards
John
Dear John,
The Curious World of Bugs is not an identification guide, but rather a pop culture introduction to the wonderful world of things that crawl.  I hope you find it entertaining.

Letter 11 – Unidentified Longicorn from Bali

 

Subject:  Mystery beetle on my window in Bali Geographic location of the bug:  Canggu, Bali, Indonesia Date: 10/18/2021 Time: 10:47 PM EDT Your letter to the bugman:  I saw this bug, it is maybe a longhorn beetle of some sort? I’ve never seen one before! How you want your letter signed:  Tommy
Longicorn from Bali
Dear Tommy, This is indeed a Longicorn in the family Cerambycidae, but we are uncertain of the species.  We will continue to research its identity.  The very long antennae seem to indicate this is a male.

Authors

    by
  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. whatsthatbug.com is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

  • Piyushi Dhir

    Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

32 thoughts on “Are Longhorn Beetles Dangerous? Some of Them Are”

  1. Hi esthar2001@yahoo.com. Most longhorn beetles (Cerambycidae) are fairly drab so I thought yours would be relatively easy to track down – not so. I suspect that your beetle is either uncommon or hasn’t made itself and agricultural or forestry pest. I took several approaches and all trails seemed to lead to the genus Batocera (sufamily Lamiinae). This genus includes several notorious pests, perhaps most notably the mango stem-borer (Batocera rufomaculata), which is a serious problem in India and many other parts of south Asia. The genus also includes a number of species with brilliant red markings. I was able to find one internet site that featured a Batocera sp. that looks very similar to yours at: http://albumo.com/photo/212955/Longhorn-Beetle—Batocera-sp..html. The photos are from Malaysia, but many Asian species are quite widespread. I suspect this may be a closely related species. Cheers. K

    Reply
  2. Hello again Esthar: I would like to correct the identification I previously suggested for this beautiful longicorn beetle. The correct species is Olenecamptus bilobus (Cerambycidae: Lamiinae: Dorcaschematini). There are numerous subspecies and as a group they are widespread throughout south and southeast Asia, as far north as Taiwan and Japan. The large spots on the elytra can be either red or white, usually bright red in India. Apparently the red color fades to white in dried specimens. The extremely long antennae (more than twice the body length in males) are also characteristic. In India they are considered a pest on a variety of fig species. The same beetle was posted again on this site by Mohit from New Delhi (April 12, 2009): http://www.whatsthatbug.com/2009/04/13/unknown-longicorn-beetle-from-india/). There are numerous photos on the internet; check out: http://www.insectsofindia.in/imagedetails.php?id=177
    Regards. K

    Reply
  3. These are edible as adults [probably as larvae also.] I had one at a banquet in Chiang Mai, Thailand, though it might not have been B.rubus but another member of the genus.
    This touches on the intriguing subject of “ethno-names,” meaning the identification system by which traditional practitioners of entomophagy identify which species or individual insects (or other foods, of course) are good to eat.

    Best,
    Dave
    http://www.smallstockfoods.com

    Reply
    • hello my name is welman cease vega I am from Dominican Republic and I am interested in the business of the beetle
      in my town are a bit rich if you are interested write me whatssap 809-750-5091

      Reply
  4. I took a photo of this insect in July 2016 on a bramble leaf on a path in a wood clearing near our house post code DH9 6YX

    Reply
  5. Hi,
    I snapped some mug shots of this beauty today in Hebden Biridge, West Yorkshire HX7. I take photographs of everything that moves but this is the first time I saw this fellow after 31 years of walking around these hills. Very pleased with the photos.

    Reply
  6. Hi,
    I snapped some mug shots of this beauty today in Hebden Biridge, West Yorkshire HX7. I take photographs of everything that moves but this is the first time I saw this fellow after 31 years of walking around these hills. Very pleased with the photos.

    Reply
    • Thanks for your suggestion, but Doug Yanega is an entomologist, more specifically a coleopterist who specializes in North American Beetles, so we defer to his identification of Strophiona laeta.

      Reply
  7. wow, i was searching to see what this beetle is or in my case was as i killed two of them this week. i imagined it may be hard to confirm but when i saw the other one from jarabacoa, it was clear especially as i am also in jarabacoa. I can not imagine people pay money for these things. How many would you like and for how much?

    Reply
    • Dear Chris, I am interested in purchase of such beetles from Jarabacoa. Can you please give your phone number to discuss the matter?

      Reply
    • Hello, I would be interested in beetles. This year I will visit the D. Republic. If you caught bugs for me, I could stop by your place.

      Reply
  8. Actually, this beetle is Neoptychodes trilineatus: https://bugguide.net/node/view/118212. It’s a flat-faced longhorned beetle (Lamiinae) like Saperda, but notice the median stripe and also the much bigger antennal scapes. In the US, this species is found mainly in the southwestern states. It also ranges down to South America.

    Reply
  9. Hi. Just found a few of these longhorn beetles on my avocado tree. Do they eat their flowers as it looks quite decimated atm. What do 8 do to deter them?

    Reply

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