Ivory Marked Longhorn Beetle Bite: Poisonous or Harmless?

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The Ivory-marked longhorn beetle, scientifically known as Eburia quadrigeminata, is a species of beetle found throughout North America. Their larvae bore into the heartwood of various deciduous trees, such as oak, hickory, maple, cherry, ash, and elm. In some cases, the lifespan of these beetles can be quite long, with adults sometimes emerging from finished furniture and flooring after 40 years source.

A common question arises about the bite of the Ivory-marked longhorn beetle: Is it poisonous? According to available information, there is no mention of these beetles being poisonous or having any venomous properties in their bites. However, one should keep in mind that beetle bites can still cause mild irritation or discomfort in some cases.

Is Ivory Marked Longhorn Beetle Bite Poisonous?

Symptoms and Effects

The ivory-marked longhorn beetle (Eburia quadrigeminata) is not known to be poisonous, so their bite is very unlikely to cause any serious harm. However, like any insect bite, there may be mild irritation or allergic reactions in some individuals. Some common symptoms include:

  • Localized redness
  • Swelling
  • Itching

Treatment and Prevention

Since ivory-marked longhorn beetle bites are not poisonous, treatment mainly focuses on reducing irritation and preventing infection. Here are some steps to follow:

  1. Wash the affected area with soap and water.
  2. Apply a cold compress to reduce swelling.
  3. Use over-the-counter hydrocortisone cream or antihistamines to alleviate itching.

To decrease the likelihood of getting bitten, consider these preventive measures:

  • Avoid disturbing their habitats, like dead or decaying wood.
  • Apply insect repellent if you are in areas where these beetles are known to be present.
  • Wear protective clothing, such as long sleeves and pants, when spending time outdoors in wooded areas.

Remember that these general guidelines are meant to help with mild reactions to a non-poisonous bite. Always consult a healthcare professional if you experience severe symptoms or have concerns about a bite or reaction.

Ivory Marked Longhorn Beetle: Biology and Characteristics

Physical Features

The ivory-marked longhorn beetle (Eburia quadrigeminata) is a brown to golden brown longhorned beetle measuring about 1/2 inch in length. Distinguishing features include:

  • Four pairs of ivory spots on wings, each surrounded by a darker brown halo
  • A small spine on each side of the thorax
  • Long antennae, longer in males than in females

Distribution and Habitat

These beetles are native to North America and are commonly found in the eastern United States. They prefer hardwood, deciduous trees such as:

  • Oak
  • Hickory
  • Maple
  • Cherry
  • Ash
  • Elm

Ivory-marked longhorn beetles often infest dead or dying trees, contributing to the recycling of nutrients in forests.

Life Cycle and Development

The life cycle of ivory-marked longhorn beetles begins when a female lays her eggs in the crevices of hardwood trees. Upon hatching, the larvae bore deep into the heartwood, where they feed and develop as grubs. During this time, they can cause damage to infested trees and finished wood products like furniture and flooring.

These beetles have an incredibly long lifespan, with adults known to emerge from wood as long as 40 years after infestation. Once mature, they take on their recognizable brown color and ivory-marked wings, and can be seen flying around during summer months.

Host Trees and Damage

Types of Trees Affected

The ivory-marked longhorn beetle (Eburia quadrigeminata) is a wood-boring insect that primarily targets hardwood trees1. Some examples of hardwood trees affected by this beetle include:

  • Oak
  • Maple
  • Ash
  • Elm
  • Hickory
  • Cherry
  • Locust
  • Birch

These beetles are also known to infest tree products, such as birch bookcases.

Signs of Infestation

Signs of infestation by the ivory-marked longhorn beetle include:

  • Circular or oval exit holes in the bark and heartwood of trees
  • Presence of larvae or grubs in the wood
  • Sawdust-like frass near the holes
Trees affected Infestation signs
Oak, Maple, Ash1 Exit holes, larvae
Elm, Hickory Sawdust-like frass
Cherry, Locust Damaged wood, leaves, twigs2
Birch Infested furniture

Although their bite is not poisonous, the ivory-marked longhorn beetle can cause significant damage to trees and tree products, especially in North America3. They are often attracted to lights at night, have long antennae, and distinctive white spots on their brown body4.

Control Measures

Wood Treatment Methods

  • Chemical Treatment: Applying chemicals like insecticides can help protect hardwood trees and furniture from infestations. For instance, treating firewood with these chemicals can prevent beetles from laying eggs and reduce the risk of infestation.
  • Physical Treatment: Sealing cracks in furniture, floors, and hardwood structures can deter beetle entry and infestation. Regular monitoring and maintenance of wooden surfaces would help avoid beetle attacks.

Monitoring and Detection

  • Visual Inspection: Check for signs of infestation like tiny holes in hardwood furniture or flooring. Additionally, inspect firewood for any signs of damage or beetle presence.
  • Traps: Setting up traps using pheromones or visual cues can help monitor and detect the presence of Ivory-marked Longhorn Beetles. This assists in early identification and prevention of infestations in hardwood trees and wooden structures.

Example Comparison Table:

Method Pros Cons
Chemical Treatment Highly effective in killing beetle larvae May require repeat applications
Physical Treatment Prevents beetle entry without using chemicals Requires regular monitoring and maintenance

Bug Control Recommendation Tool

What type of pest are you dealing with?

How severe is the infestation?

Do you require child/pet/garden safe treatments (organic)?

Are you willing to monitor and maintain the treatment yourself?


  1. Ivory-marked Borer | NC State Extension Publications 2
  2. Borer Insects on Trees | University of Maryland Extension
  3. Wood Boring Insects of Trees and Shrubs – Texas A&M University
  4. Controlling Wood-Boring Beetles in Houses | Home & Garden Information Center

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 – Ivory Marked Beetle: Alive 36 hours after poison!!!


I’ve never seen anything like this!
Location: Lake Mary, FL
May 30, 2011 2:46 pm
I live in Central Florida near Orlando. A couple of nights ago I found this bug (which I believe is some type of roach) sitting right in front of my pantry. I apologize in advance, but im kind of terrified of bugs so I sprayed it with poison… However, 36 hours later it’s still alive which is confusing. Nobody I know has ANY idea what this is. Its body is 1 1/2 inches long but the antanae are at least twice the length of the body and it has 4 silver spots on its back. Please help me identify this if possible.
Thanks, Dustin
Signature: Dustin N.

Ivory Marked Beetle

Dear Dustin,
This is an Ivory Marked Beetle,
Eburia quadrigeminata, and though it is still alive 36 hours after being doused with poison, we fear it has not long for this world as the inside of a plastic bag is not its typical habitat.  We are tagging this as an example of Unnecessary Carnage.  The larvae bore into the heartwood of a variety of hardwood trees including ash, oak, hickory, locust, chestnut, maple, elm, beech and cherry.  According to BugGuide:  “Notorious for emerging from furniture after as many as 10-40 yrs” and “Delayed emergence of E. quadrigeminata was discovered from a birch bookcase 40 years old.”

Letter 2 – Ivory Marked Beetle


Brown bug with white spots on back
July 29, 2009
I recently found this bug crawling on my floor. I grabbed my camera as I”ve not seen it before. It had 4 white spots (the image below shows 2) that looked to be pretty symmetrical.
The antenne are about 3″ long or so.
To give an estimate, it’s about 2″ long
I found this just now (Jul 29, 2009) in Missouri.
Southeast Missouri

Ivory Marked Beetle
Ivory Marked Beetle

Hi Matt,
This is an Ivory Marked Beetle, Eburia quadrigeminata, a species in the family Cerambycidae also known as the Four Marked Ash Borer.  BugGuide has some information on this species including:  “Larvae bore into heartwood of deciduous trees, esp. ash, hickory. May emerge from finished lumber years after milling.

Letter 3 – Ivory Marked Beetle burned to death


help, is this a roach???
Location: western pennsylvania
July 21, 2011 11:26 pm
Please let me know what kind of bug this is. It was in my bedroom. Ignore the light black spot between the the first two white dots(closest to the head) as my husband burned it. (Cruel I know)
I live in western Pennsylvania
Signature: Jamie

Ivory Marked Beetle

Hi Jamie,
This is an Ivory Marked Beetle, one of the Longhorned Borer Beetles.  It will not infest your home, though there are reports of adults emerging after many years from furniture that was built from wood that contained boring larvae.  According to BugGuide:  “Notorious for emerging from furniture after as many as 10-40 yrs (1)(4)  Delayed emergence of E. quadrigeminata was discovered from a birch bookcase 40 years old.”  We feel that burning a living creature constitutes Unnecessary Carnage, however, roasted insects, which are high in protein, are consumed in many cultures.  Since this Ivory Marked Beetle was photographed on a spoon, are you able to provide us with any information on how it tasted?

Letter 4 – Ivory Marked Beetle, or close relative


Subject: Ivory-marked Beetle?
Location: Northeast Florida
July 29, 2012 4:15 pm
I’ve never seen a bug like this before. It was sitting in the shade on the door of my shed this morning when I went out to mow the grass. It was still in the same shady spot in the middle of the afternoon. When the sun hit that area the beetle began to move around and left. It was about an inch long with very distinctive markings. I hunted through beetles on Bug Guide and I think this is an Ivory-marked Beetle (Eburia quadrigeminata). The markings match but the body color is a little different. Can you help?
Signature: Karen in FL

Possibly Ivory Marked Beetle

Hi Karen,
This is the third Longhorned Borer Beetle in the family Cerambycidae that we are posting in a row this morning.  This might be an Ivory Marked Beetle,
Eburia quadrigeminata, though there are other members in the genus Eburia that look very similar.  We could not discount that it might be Eburia distincta, a species that feeds on Cypress trees and which BugGuide only reports from Florida.  There are also several other species in the genus that are only reported from Florida.

Letter 5 – Possibly Ivory Marked Beetle from Belize


Spots, legs and antennae
Location: Belmopan, Belize
December 22, 2011 1:45 pm
Hi! As always, I love perusing your site. I found this guy on my screen and have no idea what it is. The screen mesh is 1/2”, so is body is about 1”. Pretty neat, whatever he is!
Signature: Cindy

Ivory Marked Beetle

Hi Cindy,
Despite the yellow color of the markings, we believe this is an Ivory Marked Beetle or Four Marked Ash Borer,
Eburia quadrigeminata, or at least a member of the same genus.  Most of the individuals on BugGuide have lighter markings, though one mounted specimen from West Virginia has markings similar to your beetle.

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 – Purplescent Longhorn


What is this beetle?
Thu, Jul 2, 2009 at 5:43 PM
This insect was seen crossing blacktop in in early July. Help me identify it please!
Lebanon, Pa

Purplescent Longhorn
Purplescent Longhorn

Dear Jason,
It took a short time for us to properly identify this striking Cerambycid on BugGuide, but we have identified it as Purpuricenus humeralis.  The species has no common name, but the genus is known collectively as Purplescent Longhorns.  This is a new species for our website and we are very thrilled to post your photo.

Letter 2 – Longicorn from Brazil with feathered antennae is Psygmatocerus wagleri


Brazilian bug from semiarid region
July 16, 2009
Hi Bugman! I was found this bug in Brazil, state Pernambuco. Looks a Cerambycinae but I can not identify. Can be an unknown species?
Brazil, state Pernambuco

Unidentified Longicorn from Brazil
Longicorn from Brazil:  Psygmatocerus wagleri

Dear Balazs,
We are a bit pressed for time this morning, and have not had any luck identifying your longicorn.  We believe it is one of the Prionids and the feathered antennae are quite distinctive.  We have seen similar antennae on an Australian Longicorn, Piesarthrius marginellus, but that is obviously a different species.  Hopefully, one of our readers will write in with a correct identification and link.

Unidentified Longicorn from Brazil
Longicorn from Brazil:  Psygmatocerus wagleri

Update:  From Eric Eaton
Realized I hadn’t been to the WTB for too long.  Shame on me:-)  I’ll get to the longhorn, but meanwhile….

Update:  From Eric Eaton
Congratulations to Tina for coming to the same conclusion I would have for the wonderful Brazilian longhorn:  Psygmatocerus wagleri.  I hope she knew which subfamily to look under!  LOL!  Still would have exhausted my lunch hour hunting for that one when I ‘do’ know where to look!

Letter 3 – Unknown Longicorn from California is Acanthocinus principes


Some kind of longhorn beetle?
July 18, 2009
This insect had apparently been attracted to the yard light at the corner of our house. It’s July, in a woodsy area of the Sierra Foothills near Placerville, California. (Lots of ponderosa pine and black oaks, as well as manzanita shrubs.) In my I.D. search I keep coming across the Banded Alder Borer but this is something else. Can you help?
Karen Rathbun
Placerville, California

Unknown Longicorn from California
Acanthocinus principes

Hi Karen,
You are correct that this is not a Banded Alder Borer, but we have had no luck in securing an identification for you.  We are nearly certain your beetle is in the subfamily Lamiinae which includes the genus Monochamus.  We would seriously consider the White Spotted Sawyer, but the male of the subspecies found in California and Oregon has solid black antenna.  We are going to contact Eric Eaton in the hopes that he can assist in an identification.

Unknown Longicorn from California
Acanthocinus principes

Comment from Eric Eaton
I recognize it, but never committed the name to memory because it is not seen that often.  I’ll get more of my colleagues to take a look. Nice images that I hope will also get posted to Bugguide:-)

Okay, I’ve submitted it to BugGuide, and also added one more photo. I’m excited that this one is not common, and now I wish I had not been rushed when taking the photos and had done a proper job of it — including a size reference and finding better lighting and that sort of thing. Or that I had saved the beetle for a proper photo session later. Thanks for your help!

July 19,2009
Daniel, thanks for your help! I thought you would like to know that Eric has identified this beetle as Acanthocinus principes  —  http://bugguide.net/node/view/306477/tree
What fun to be able to provide photos that seem somewhat hard to come by!  I just got lucky, as I know next to nothing about insects, though I do own a couple of field guides and like to learn the names of things that I find.  I sure appreciate your service, and also Eric’s.

Letter 4 – Longicorn from U.K.


Beetle identification
August 3, 2009
Dear Bugman
I found this beetle out side of my workplace, in Winsford (UK).
I have looked around and think it is a fur less Ornate Checkered Beetle .
It was very lethargic, it’s hard shell contained wings, that were jet Black
Can you confirm this please?
Richard Lock
Winsford, UK

Unknown Longicorn from U.K.
Longicorn from U.K.

Dear Richard,
While we cannot confirm the species at this point in time, we can tell you that this is not a Checkered Beetle, but is a Longhorned Borer Beetle or Longicorn in the family Cerambycidae.  We found one Longhorn Beetle page on the Garden Safari website devoted to U.K. Beetles, but your individual is not represented.  We also found a comprehensive Cerambycidae site without thumbnails and our cursory search did not turn up a match.  We believe your beetle must be represented on that site.  If you feel so inspired, and you find your beetle, please let us know.  Meanwhile, perhaps one of our readers will supply an answer.

Comment with identification
This is a Leptura quadrifasciata L. 1758. Formerly known as Strangalia quadrifasciata. By the looks of it it is a male because the tip of female antennae is yellow (last three segments). Males have black antennae. It is a widespreaded and common longhorn, at least in the Northern Europe. You can find them on flowers. In that site what you mentioned that guy is on page
http://www.cerambyx.uochb.cz//lquadri.htm .
By the way sorry for my bad grammar.

Letter 5 – Poinciana Longicorn? or other Prionid from Australia???


Need more information
November 21, 2009
Hey bugman,
I’m from Woodford, Queensland in Australia, and have recently had an increasing (then decreasing) number of what I have found out (from your site) to be Brown Prionids. A good deal of my room is made of timber from the timber yard next door, and I have a full length porch made from said timber around my room. Just wondering if these beetles are dangerous in any way. The pincers on these buggers are freaking my missus out BIG TIME! And the little buggers have flown across the room, brushed my face while lying down, and freaked my missus out a few times. Any further information than that I have already read about them on this site would be greatly appreciated.
Thank you in advance,
Nathan from Brisbane
We don’t see bugs like this in Australia, really…. :-S
Woodford, Queensland

Poinciana Longicorn from our archives

Ed. Note:  January 30, 2012
The included photo came from another posting and is replacing a photo we originally incorrectly identified as the Poinciana Longicorn.

Hi Nathan,
Though our website has gotten you a subfamily identification, we actually believe your species may be local for you.  In our opinion, this may be a Poinciana Longicorn, Agrianome spinicollis, or perhaps some closely related species.  When you say your room is made from the timber from the timber yard next door, you did not indicate when the room was constructed.  Often fresh timber is milled with beetle larvae inside, and if the wood is not treated, the adults may eventually emerge.  Also, if you live in an area where milled wood is produced, you may just be attracting the beetles because many Prionids are attracted to lights.  The mandibles on Prionids are quite strong since they need to chew their way out of the trees they have been boring in during the larval stage.  A bite might even draw blood, but it will heal as there is no poison.  Perhaps someone will write in an confirm that our identification is correct.  We posted a photo of a Poinciana Longicorn several years ago, and there is also a link to a site with some photos.  Your specimen seems a richer color than the images we found online.  Sadly, the Brisbane Insect website has nothing devoted to the subfamily Prioninae.

Hey Daniel,
The house was built roughly 5 years ago. These beetles have only JUST started to show up. The owners of the house before us have stated they have no idea what we’re on about because they didn’t have them. As I said, they seemed to show up almost every night (for about 2 weeks), then all of a sudden they stopped showing up as often. We now see 1 every now and then. Ironically, the beetles stopped showing up as often when we caught one and kept it in a bottle. They must be tough bugs, because this bugger lasted 2 weeks without food, water or air…
And the picture I included was one I found on the internet. I didn’t have a camera on me when I sent that message to you. In actuality, the beetles we have here are a deep brown colour, as opposed to the rich red-like colour in the photo.

Hi Again Nathan,
We wish you had indicated that the beetle in your photo was just some random similar looking specimen, because as you should realize, any accurate identification is now impossible.  We will be removing the image from your letter (since we do not have the photographer’s permission to use it) and replacing it with the likeliest suspect, the Poinciana Longicorn.  Often there are years with population explosions of some species, generally triggered when conditions are perfect.  While it is possible that the beetles have been in the larval stage in the wood of your house for the past five years, we do not consider that as strong a possibility as them entering the home from the outside after being attracted to the lights.

Hey Daniel,
First off, my apologies for including a random shot of the beetle from the internet. But as your inquiry form would not allow me to continue without a photo (and the fact I didn’t have a camera on me at the time) I grabbed the next best thing.
I ran an image search of this Poinciana Longihorn, and found a closer image match to this beetle than I originally did, so I now have a better idea of what this bug is, thank you. And I’m not sure if they are actually attracted to the lights, per say, because if you leave the doors open, they DO enter (and the outside lights are always on of a night). Every time I have accidentally left the door open, I see them flying in. So needless to say, I now make every conceivable effort to keep the house closed up of a night.
A larval stage of 5 years??? Freaky… 🙂
Anyways, I want to thank you for helping me trying to understand this small creature and giving me a little more appreciation for them. I no longer kill them. Rather, pick them up with some paper and a glass, and set them back into the backyard.

Letter 6 – Longicorn from Peru


Big Prionid-like Longhorn
December 19, 2009
Found this guy on the same hike as the assassin bug. About the same size as a prionid but with longer curving antennae. Very cool Coleopterid.
About two hours downstream from Iquitos, Peru

Unknown Longicorn from Amazon
Longicorn from Amazon

Hi again Sebastian,
This Longicorn is not a Prionid, but rather, it is in one of the other Cerambycidae subfamilies, perhaps Lamiinae.  We hope to get you a species identification on this beauty.  We attempted to search the Cerambycids of Brazil website, but after going through about a third of the possibilities in the subfamily, we decided to take a nap.

Update from Karl
I believe the subfamily is Cerambycinae (tribe Cerambycini), but it gets difficult after that. If you look at the ‘Cerambycidae de Guyane’ website you get an idea of some of the generic paths this could go down. All things considered, I would probably go with Jupoata as the genus and rufipennis as the species. It looks about right, is large, common and widespread (Mexico to northern Argentina). However, it could also be J. costalimai, or one of several other similar species. If you are looking on the Cerambycids of Brazil website, you will find this genus filed under the older name Brasilianus, which has subsequently been redistributed among several genera. Regards.

p.s. Here are the links if my hyperlinks did not migrate:





Letter 7 – Katydid from Borneo


Borneo to be Weird
December 29, 2009
Spotted at night while trekking in Borneo. This insect was quite large (around 12 cm), and was found at our camp in Maliau Basin. I have no idea what it is, but I’m guessing that it’s some type of stick insect. This individual is the only one of its kind that we saw during our three weeks in Malaysia. I would love to know what it is.
Maliau Basin, Sabah, Malaysia

Mystery from Borneo
Katydid from Borneo

Dear Croix,
Tropical species can often be very difficult to recognize, and diversity in the jungles often results in a physiognomy that is nearly unrecognizable from closely related species found in well documented areas like North America.  We believe this is some species of Longhorned Orthopteran, but we will probably need some time to research that possibility.  Meanwhile we are going to post your photos of this fascinating creature with the hopes that we can identify it online, or that our readership may be able to contribute to the identification.

Mystery from Borneo

We are also going to contact Eric Eaton to see if he is able to confirm that this is a Longhorned Orthopteran.

Mystery from Borneo

A Differing Opinion
I think that the insect on the picture should be some kind of Phasmatodea. If I look the third leg pair in the third picture then I can’t imagine how could he jump. The head is also like Phasmatodea’s have.

Thank you for posting my submission and replying as quickly as you did. I really enjoy your site, and I’m excited to see if someone will be able to identify this insect. Have a wonderful new year.
All the best,

Eric Eaton writes back
Hi, Daniel:
I’m “cc’ing” Piotr Naskrecki because the images are of a katydid, and Piotr is the most knowledgeable and helpful authority I know for this group of insects.  He will likely know the genus at least.  Wonderful creature!
Best wishes to you and Lisa for a very prosperous and stress-free 2010.

Katydid Expert Piotr Naskrecki provides an answer
Hi Eric,
This pretty animal is either the genus Olcinia or Sathrophyllia, both common
katydids in Borneo and peninsular Malaysia (hard to tell them apart without
seeing the wing venation.) They are members of the Pseudophyllinae:

Wow!  That was ridiculously fast, Piotr:-)  Thank you so much.  I am getting a wonderful education from you.  I have always liked katydids anyway, but you have only increased my fascination and wonder through your helpful comments and identifications.  Thank you again, and happy new year to you!

Letter 8 – Spiny Lobster Katydid from Ecuador: Panoploscelis specularis


Ecuadorian Giant Red Grasshopper
November 9, 2009
We noticed this insect crawling around our lodge one night. The natives told me that it was called a ‘lobster bug,’ and that it may be the adult version of a grasshopper which loses it’s wings at an old age. The wings do appear to be shriveled, and it’s movements were slow. It is several inches long, easily over 8 inches. Hope you can help me identify this beauty.
P.S. His name is Bladerunner
Anthony L.
Napo Valley, Ecuador

Longhorned Orthopteran
Panoploscelis specularis

Dear Anthony,
We randomly selected your letter from our older unanswered mail to post today.  This is some species of Longhorned Orthopteran and we are going to write to an expert in the order, Piotr Naskrecki, to see if he can give us a species or genus identification.  Based on the presence of an ovipositor, we hve to inform you that Bladerunner is a female.

Longhorned Orthopteran
Panoploscelis specularis

Identification thanks to Piotr Naskrecki
Hi Daniel,
This is a female of Panoploscelis, almost certainly P. specularis
(Pseudophyllinae: Eucocconotini). It is an interesting animal, one in which
the female has fully developed stridulatory organs on her wings, albeit ones
that are not homologous with those of the male. It really is a huge animal,
although probably not 8 inches long, more like 5, ovipositor included (at
least I have never seen an individual longer than that.)
Happy New Year!

Ed. Note
Now that we have a name, we searched for some online information and found a detailed scientific paper.  We also found a reference to a common name Spiny Lobster Katydid.

Letter 9 – Longicorn from Vietnam


Vietnam Beetle
January 5, 2010
My friend Emma found this beetle on a street in Ho Chi Minh city, outside of Saigon. She took this picture in early July 2008. I’m very much an amateur entomologist, and I’m not sure about the identification. Any help you could offer would be much appreciated. Thanks!

Unknown Longicorn
Longicorn:  Pachyteria dimidiata

Hello Kai,
This is some species of Longicorn in the family Cerambycidae, though we need to research the species.  Perhaps one of our readers will beat us to the correct identification.

Update from Karl
This looks like Pachyteria dimidiata (Cerambycinae: Callichromatini), found throughout tropical and sub-tropical Asia from Iran to Borneo. In Thailand it is considered a wood boring pest on fruit and ornamental trees, particularly the Iron Wood Tree (Mimusops elengi); in fact the common name there appears to be the Mimusop Stem Borer. You can find another photo of this beetle (also from Vietnam) on WTB at: 2009/08/01/longicorn-from-viet-nam-pachyteria-dimidiata/

Thanks Karl,
We knew it looked vaguely familiar, but we didn’t have time to research the matter earlier today.

Letter 10 – Engraver Beetle Galleries


Bug ID from burrowing pattern
January 16, 2010
I was walking through a wetland forest near Brockville, Ontario when I happened upon an interesting dead tree. The pattern left behind after the bark had fallen off was quite impressive. There were no clues as to what insect made this pattern. Is there anyway to determine the identity of the bug that makes this type of pattern without having to catch it first?
Claire B
Brockville, Ontario Canada

Engraver Beetle Galleries

Hi Claire,
These are most probably the galleries of a Wood Boring Beetle, though we are uncertain if they are from the family Cerambycidae or Buprestidae.  A species identification is nearly impossible.  We will see if Eric Eaton has an opinion on this.

Eric Eaton provides some information
Hi, Daniel:
The galleries etched in the trunk of the dead tree are the work of “engraver” beetles of some kind, family Curculionidae, subfamily Scolytidae.  The central, vertical passage is the “egg gallery” bored by the female as she laid eggs along each side.  The perpendicular tunnels are the result of the larvae boring through the wood before pupating at the end of each tunnel and emerging through the bark at the end of their life cycle.  Knowing the host tree would be helpful in determining which species of beetle this represents.

Letter 11 – Purplescent Longhorn


bug identification
January 19, 2010
Hello! I found this bug on my patio on July 30, 2009 in Swiftwater, PA. I haven’t found anyone who can help me identify it yet. Do you know what it is? He’s pretty cool looking! He was about an inch and a half long (body, that is).
Swiftwater, PA

Purplescent Longhorn Beetle

Hi Susan,
This is sure a handsome beetle.  It is a Purplescent Longhorn in the genus Purpuricenus, which is well represented on BugGuide.  Our choice for the species is Purpuricenus humeralis, which is found in the Eastern states according to BugGuide.


  • 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.

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  • 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.

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  • Could it possibly be Psygmatocerus wagleri? I was searching around on the same site that your expert Eric Eaton used to i.d. the Feather Horned Longicorn from Australia, and I came across this link… http://www.cerambycoidea.com/foto.asp?Id=891 Hope this helps.


  • This is a Leptura quadrifasciata L. 1758. Formerly known as Strangalia quadrifasciata. By the looks of it it is a male because the tip of female antennae is yellow (last three segments). Males have black antennae. It is a widespreaded and common longhorn, at least in the Northern Europe. You can find them on flowers. In that site what you mentioned that guy is on page
    http://www.cerambyx.uochb.cz//lquadri.htm .

    By the way sorry for my bad grammar.

  • I think that the insect on the picture should be some kind of Phasmatodea. If I look the third leg pair in the third picture then I can’t imagine how could he jump. The head is also like Phasmatodea’s have.

    • Katydid Expert Piotr Naskrecki provides an answer
      Hi Eric,
      This pretty animal is either the genus Olcinia or Sathrophyllia, both common
      katydids in Borneo and peninsular Malaysia (hard to tell them apart without
      seeing the wing venation.) They are members of the Pseudophyllinae:

  • This looks like Pachyteria dimidiata (Cerambycinae: Callichromatini), found throughout tropical and sub-tropical Asia from Iran to Borneo. In Thailand it is considered a wood boring pest on fruit and ornamental trees, particularly the Iron Wood Tree (Mimusops elengi); in fact the common name there appears to be the Mimusop Stem Borer. You can find another photo of this beetle (also from Vietnam) on WTB at: http://www.whatsthatbug.com/2009/08/01/longicorn-from-viet-nam-pachyteria-dimidiata/

  • is the ivory marked beetle poison. it bit a youth and died after it bit. the youth says he feels ill now. was this caused from the bug bite

  • Is this bug poisonous??

  • I found this bug in my kitchen. I had shopped at 3 stores one of the stores is Ollie’s a discount store which has a little of everything I was in the pottery dept for while and the items that I bought when I got home I put on the counter in the kitchen, later that evening I found this bug the ivory marked beetle

  • Well if these are supposed to be in FLA. they are definitely on the move. I live in TN & had one land on the neck of my shirt this evening. This isn’t the first time I’ve seen one either. My wife found your website while trying to identify it.

    • The Ivory Marked Beetle has a much greater range than just Florida. See the map of reported sightings on BugGuide which includes Tennessee.

  • Kathleen Hayes Wildrick
    July 13, 2015 5:56 pm

    An Ivory Marked Beetle appeared the other night on the mirror in my children’s bathroom. I’d never seen such a beetle before and understand that it’s larvae can rest for 10-40 years inside wood or furniture. I live in central NJ. Questions: Will there be more of these in my house? I put it outside–was that the wrong thing to do? Should I notify anyone about this beetle being in my house and now outside? (Someone said I should not have put it outside!)

    Thanks for your help.

    • They are native to your area, so releasing the beetle is not a problem. We would suspect that the adult beetle entered the home, perhaps being attracted to the lights, sooner than we would suspect it emerged from milled lumber, though that is a possibility.

  • I saw it flying around in my den, knocked it down, found it 2 days later still living, put it in water and took it out still moving it’s legs. slowly dying i hope!

  • I was bit by a Ivroy beetle I want to know if it will make me sick

  • Cheryl Burke
    August 1, 2016 8:45 am

    I have found two of these in my house this week. First in a downstairs bathroom, the second in an upstairs bathroom. Both were on the wall near the sink. What should I do with it? If it found on hardwood trees, how is it in my house?

    • Either they were attracted to lights, or they might have emerged from wood paneling or furniture.

  • I do believe I have witnessed the birth of two, mere inches from one another, however, 2 weeks apart. The 2×4 that holds my garage door opener is directly above where I found them, and there are two holes, 3/16 to 1/4 of an inch, with grey…..something…inside.
    That 2×4 was there long before I moved here, 11 years ago.

    • The Ivory Marked Beetle is notorious for emerging from wood milled many years before the sightings.

  • This was quite helpful! I found one of these little fellows on my wall! I released him into my yard in SW Missouri. I had never seen one before! I ran inside to get my camera (I’m a photographer) and when I came back, it was gone!

  • Found one on my night stand, scared the crap outta me although now learning hes harmless gives me peace of mind.

  • Angel Sho Jr
    July 11, 2019 2:07 pm


  • Found one of these on the back of my shirt. I felt it bite me, glad to have found this site to know it’s not poisonous. I did scare the bajesus out of me though. I took a picture of it with the google pic app. Love this app I will say or I probably wouldn’t have known what it was. I live in Baton Rouge, Louisiana thanks


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