Banded Alder Borer: Essential Facts & Tips for Pest Control

The banded alder borer (Rosalia funebris) is a visually striking beetle native to the Pacific Northwest.

Often encountered between March and August, this insect is characterized by its bold white-blue and black coloration, making it stand out among other beetles.

They primarily infest alder, ash, and California laurel trees, with occasional appearances on other hardwoods as well1.

In order to manage and control the banded alder borer population, it is essential to have some knowledge about this species.

Here’s what you need to know to understand these fascinating creatures further.

Banded Alder Borer
Banded Alder Borer

As mentioned earlier, their unique appearance makes them easily identifiable. In addition, they play a role in breaking down dead and dying trees, making way for new forest growth1.

However, the banded alder borer can also cause some problems. If it infests healthy trees, it can cause structural damage and make them more susceptible to other pests and diseases.

It is crucial to strike a balance between understanding their ecological role and responsibly managing their populations to maintain healthy forest ecosystems1.

Banded Alder Borer Identification

Physical Features

The Banded Alder Borer (Rosalia funebris) is a distinctive beetle known for its striking appearance. Some key physical features of this species include:

  • Coloration: They have a unique white-blue and black pattern on their elytra (wing covers).1
  • Antennae: These beetles possess long, black antennae, which can be as long as their body.
  • Size: They are generally around 1 inch (2.5 cm) in length.

Banded Alder Borer

Similar Species

Although the Banded Alder Borer has a distinct appearance, it can sometimes be confused with the California Laurel Borer (Rosalia funebris).

Both species share a black and white pattern, but there are noticeable differences:

FeatureBanded Alder BorerCalifornia Laurel Borer
ColorWhite-blue and blackBlack and gray
AntennaeLong and blackShorter and gray
PatternBold bandsLess defined pattern
HabitatAlder, ash, and occasionally other hardwoods1Primarily California laurel^[2]

By comparing these characteristics, it is easier to distinguish between the Banded Alder Borer and the California Laurel Borer.

Distribution and Habitat

Geographical Range

The Banded Alder Borer (BAB) is predominantly found in North America, specifically in the Pacific Northwest region, including parts of the U.S., Canada, and Alaska1.

In the United States, its range extends from Alaska to California, and eastward to Montana and New Mexico2.

Host Trees

BAB mainly infests hardwood trees, such as:

  • Alder
  • Ash
  • California Laurel
  • Willow
  • Oak

Occasionally, it targets other hardwood species as well3. In Asia, these beetles have been reported to infest ash trees4.

The following table summarizes the BAB’s preferred host trees and their common regions:

Host TreeCommon Regions
AlderNorth America, Alaska
AshNorth America, Asia
California LaurelCalifornia
WillowNorth America, Mexico
OakNorth America, Canada

Life Cycle and Behavior

The Banded Alder Borer (Rosalia funebris) is a beetle from the family Cerambycidae. This species has a distinct life cycle that goes through three stages – eggs, larvae, and adults.

Eggs

  • The female Banded Alder Borer deposits eggs in cracks or crevices of hardwood trees.

Larvae

  • After hatching, the larvae burrow into the wood, feeding on its tissue.
  • This stage can last for up to two years.

Adults

  • They emerge from the trees, displaying distinctive black and blue-white patterns.
  • Adults are active from March to August.

Key characteristics:

  • Family: Cerambycidae
  • Host trees: Alder, Ash, California Laurel, and occasionally other hardwoods
  • Life cycle: Three stages (eggs, larvae, adults)
  • Migratory patterns: Predominantly Pacific Northwest

Here’s a comparison of Banded Alder Borer (BAB) with a common pest, the Emerald Ash Borer (EAB):

FeatureBanded Alder BorerEmerald Ash Borer
FamilyCerambycidaeBuprestidae
Host treesAlder, Ash, LaurelAsh trees
RegionPacific NorthwestNorth America
Major damageAesthetic damageTree death
(info from BAB and EAB)  

To summarize, Banded Alder Borers go through three life stages and are primarily found in the Pacific Northwest region, where they feed on hardwood trees such as Alder and Ash.

While their presence can cause aesthetic damage to trees, they are not as destructive as the invasive Emerald Ash Borers.

Classification and Evolution

Taxonomy

The Banded Alder Borer (Rosalia funebris) is a species of beetle belonging to the order Coleoptera, which is the largest order of insects.

It falls under the class Insecta and the phylum Arthropoda. Here is the detailed classification of the Banded Alder Borer:

  • Phylum: Arthropoda
  • Subphylum: Hexapoda
  • Class: Insecta
  • Order: Coleoptera
  • Suborder: Polyphaga
  • Superfamily: Chrysomeloidea
  • Subfamily: Cerambycinae
  • Tribe: Compsocerini
  • Genus: Rosalia
  • Species: Funebris

Evolutionary History

The evolutionary history of the Banded Alder Borer is not well-documented.

However, it is a member of the Cerambycinae subfamily, which has a diverse and expansive evolutionary history.

This subfamily is part of the Chrysomeloidea superfamily, which includes thousands of species and is known for its distinctive wood-boring and plant-feeding habits.

The Cerambycinae subfamily originated from a common ancestor dating back 100–200 million years ago, evolving a range of unique features and behaviors:

  • Long antennae, often longer than their body length
  • Vibrant and colorful patterns on their bodies
  • Wood-boring and plant-feeding habits

Interactions with Humans

Impact on Trees

The Banded Alder Borer (BAB), like other types of longhorn beetles, can affect certain tree species, including alder, ash, and California laurel.

Although not considered highly destructive, they may still cause damage to trees under the right circumstances or when populations become large 1.

  • Injury: Borer larvae feed on the inner wood of the trees, creating tunnels that can weaken the tree’s structure.
  • Tree stress: Trees that are already stressed from other factors, such as poor environmental conditions or disease, are more susceptible to borer attacks.

Prevention and Management

There is no foolproof method to prevent an infestation of the banded alder borer, but there are steps that can help protect trees from these insects:

  1. Maintain tree health: Proper watering, fertilization, and pruning can help keep trees healthy and less attractive to borers.
  2. Monitor: Regularly check your trees for signs of borer infestations, such as exit holes or sawdust-like frass around the tree’s base.

In terms of management, if an infestation is already present, a few options may help reduce the population and further damage to the tree:

  • Mechanical control: For smaller infestations, physically removing the affected parts of the tree can help prevent further damage.
  • Chemical control: In some cases, the application of an insecticide may help control the borer population, but be sure to consult with an expert before using chemicals.

Remember, while banded alder borers do have an impact on trees, they are not considered a significant threat to healthy, well-maintained trees.

By monitoring and taking preventive measures, it is possible to minimize the impact of these insects on our trees and landscapes.

Conclusion

To summarize, the Banded Alder Borer (Rosalia funebris) is a visually striking beetle native to the Pacific Northwest.

In this article, we have delved into the essential facts about this beetle, including its unique physical features, habitat, and life cycle.

While the beetle plays a role in breaking down dead and dying trees, it can also cause structural damage to healthy trees.

We have provided tips for managing and controlling the banded alder borer population, including maintaining tree health and monitoring for signs of infestation.

Chemical and mechanical control methods are also discussed.

Footnotes

  1. (https://entomology.oregonstate.edu/sites/agscid7/files/entomology/Banded_Alder%20Borer_13.pdf 2 3 4 5 6 7
  2. https://extension.okstate.edu/fact-sheets/shade-tree-borers.html 
  3. https://entomology.oregonstate.edu/sites/agscid7/files/entomology/Banded_Alder%20Borer_13.pdf 
  4. https://extension.oregonstate.edu/collection/emerald-ash-borer-resources 

Reader Emails

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

Letter 1 – Banded Alder Borer

Subject: Striking black and white beetle!
Location: Seattle, Washington
August 1, 2012 10:33 am
Hello,
My husband sent me a text with this picture of a large black and white striped beetle with incredible antennae (also striped)and asked me what it was.

I work in fisheries but have no idea when it comes to bugs, so I did some internet searches and could only find pictures of beetles with more mottled black and white coloration, not the very distinct stripes this guy has. Just wondering if you guys can tell me what it is?


Signature: From a curious ichthyologist

Banded Alder Borer

Dear curious ichthyologist,
This might well be our favorite North American beetle, the Banded Alder Borer.  It is found in the western portion of North America.  It really is a stunning looking beetle.

Letter 2 – Banded Alder Borer

Subject: need identification
Location: santa rosa, ca
July 13, 2012 12:05 am
Love to know what this bug is..
Signature: marion

Banded Alder Borer

Hi Marion,
While it might not be appropriate for the staff of What’s That Bug? to have favorites, the Banded Alder Borer,
Rosalia funebris, in your photograph is probably our favorite North American Beetle. 

The Banded Alder Borer is found in the western states from California to Washington, into Canada.  BugGuide also has reports from Idaho and Utah.

Thank you so much for your quick reply.  We are so impressed with this bug. The one you see the photo of is the male.

A few minutes later another larger one appeared, which turned out to be the female.  The smaller one reacted instantly by mating the with larger beetle.  Thank you again.
Marion and Kent

Hi Marion and Kent,
You are such teasers to tell us that information and then not send a photo.  It is also very curious that the female found the male.  It is generally believed that female insects release pheromones and males are attracted to the “scent” of the females by using their more developed antennae. 

Sometimes both sexes are attracted to other scents or to food supplies and mating takes place at a jointly attractive location. 

Charles Hogue writes in Insects of the Los Angeles Basin:  “Adults may be attracted to the volatilizing esters in fresh paint.”  We hope you took a photo of the mating activity that you can send to us.

Letter 3 – Banded Alder Borer

Do you have any idea what this is?
I found this in the back seat of my CAR!! Any idea what it is or why it would be there?

We just removed a two week old image of a Banded Alder Borer from our homepage since we didn’t get any additional requests for identifications. Generally at this time of year we get numerous requests for the identification of this beautiful beetle.

We have read that they are attracted to paint fumes, and perhaps the pine scented hanging air freshener you might have had in your car attracted it. It could also just be an accidental passenger.

We have overcome our annoyance that you did not provide a location of the sighting to benefit our readership. Often, when there is no location provided, the letter goes straight to the trash, but we thought your photo was lovely.

Thank you so much! I am sorry I kind of got straight to the point! My husband works in the desert so I thought maybe he brought it home with him on accident.

We live in Tooele, Utah. We have been recently remodeling some of the house, I have been taking advantage of the nice weather and painting outside to reduce the fumes in the house, which goes along with what you said. Thanks agian for all of your help!

Letter 4 – Banded Alder Borer

bug
I have never seen one of these in 22 years in Napa Valley! It is about one and a half inches in length. There are two of them.
Larry

Hi Larry,
This is a Banded Alder Borer, Rosalia funebris.

Letter 5 – Banded Alder Borer

Can you tell me what this is?
I was out in my garage last night and i found this!?! I live in Yelm, Washington and have for most of my life i have never seen this before. Can you help me figure this out? Thanks You Sincerely,
Andria Roper

Hi Andria,
In our humble opinion, the Banded Alder Borer, or Laurel Borer, Rosalia funebris, is one of the most beautiful and elegant North AMerican beetles.

Letter 6 – Banded Alder Borer

what’s this bug?????
Dear Bug Man,
We found this at strip mall in Temple City,California. What is it? Thank You,
Dominic Valenzuela, 41/2 yrs. Bye!
Jennifer M. Luna-Valenzuela

Hi Dominic and Jennifer,
This beauty is a Banded Alder Borer, Rosalia funebris.

Letter 7 – Banded Alder Borer

What is this bug?
I found this bug right next to my work, I have no idea what it might be. I would love to know what it is, as well as if its venomous (harmful). Thank you in advance
Andranik

Hi Andranik,
The Banded Alder Borer is neither venomous nor harmful.

Letter 8 – Banded Alder Borer

Hi,
We had these all over our building yesterday, it was very hot and they were only in the shade. Can you tell me what it is?Thanks
Ian
Victoria BC, Canada

Hi Ian,
This is one of the most beautiful images we have ever received of what is, in our opinion, North America’s most beautiful beetle, the Banded Alder Borer, Rosalia funebris. Here in Southern California, this beetle is also known as the California Laurel Borer.

Letter 9 – Banded Alder Borer

Black & white striped bu
My friends and I found this beautiful black and white bug in the parking lot at Performance Bike on Arroyo Parkway, Pasadena, CA, on a hot Independence Day morning. We’d love to know what it is.
Clare Scott & friends

Hi Clare and friends,
We have posted several blurry Banded Alder Borer images in recent weeks, including some from the Pasadena area. We are happy to finally receive a high quality photograph of this gorgeous insect.

Letter 10 – Banded Alder Borer

Flying Bug
Hi wtb,
Can you identify this bug for me? Its body is approximately 1.25″ long. I don’t know what plant he was on having spotted him on our stucco wall where he stayed about 2 – 2 1/2 days, then he went his way. Thanks,
Ray B

Hi Ray,
We got many requests for the identification of Banded Alder Borers several months ago. Sadly, your letter did not indicate where or when you took this image.

Letter 11 – Banded Alder Borer

large black &white striped bug with thick antena
July 8, 2010
i spoted this bug crawling on a wall in by back yard. It scared the heck out of me .i had never seen anything like it before. any idea what it is?
christina
southern california

Banded Alder Borer

Hi Christina,
This Banded Alder Borer or California Laurel Borer,
Rosalia funebris, is a native insect that is sometimes attracted to paint fumes.

Letter 12 – Banded Alder Borer

black and white striped bug
July 14, 2010
I found this bug located against the side of a building in Downtown Vancouver and had never seen it before. It has been there for two days in the same location and only moved up or down the wall. It is currently summer and warm between 15C and 23C.
Curious in Vancouver
Vancouver, BC Canada

Banded Alder Borer

Hi Curious,
The Banded Alder Borer,
Rosalia funebris, ranges from Alaska to California on the west coast, and in California is is also known as the California Laurel Borer.

Letter 13 – Banded Alder Borer

unknown bug
Location:  Grants Pass, Oregon
August 16, 2010 8:57 pm
We were hoping you could help identify this bug we saw on vacation. Never seen anything that looked like this before.
Thanks!!
Jenny

Banded Alder Borer

Hi Jenny,
In our opinion, the Banded Alder Borer, the insect represented in your photograph, is probably the most beautiful North American beetle.

Thank you!  You’re right it was very beautiful and unique.  🙂

Letter 14 – Banded Alder Borer

Random BugLocation:  Northwest – Washington State – Western side
August 16, 2010 7:45 pm
Me and my family have been trying to figure out what this guy is. He seems to have poped out of no where. He seems to have beetle features but is black and white with a horizontal line pattern up his back. Also just below his head is a giant black circle.
Kiriku

Banded Alder Borer

Hi Kiriku,
We just finished posting another photo of a Banded Alder Borer, also known as a California Laurel Borer,
Rosalia funebris, just a few minutes ago.

Letter 15 – Banded Alder Borer

What kind of beetle is this?
Location:  Western Washington State
September 16, 2010 3:17 am
I found this bug crawling on my kids trampoline. I do have a cedar tree by the trampoline. I believe it is a beetle but would like to know what kind and if it is trouble for my plants.
Signature:  Tawny

Banded Alder Borer

Hi Tawny,
For some reason, many of the images we receive of the Banded Alder Borer,
Rosalia funebris, are of very poor quality, either being blurry or of low resolution, so it is refreshing to have received your marvelous photograph of this stunning insect.

Letter 16 – Banded Alder Borer

What is this??
Location: Idaho
October 29, 2010 11:18 pm
I am curious? =] Please help!
Signature: DR

Banded Alder Borer

Dear DR,
This beautiful beetle is commonly called the Banded Alder Borer, though in California it is known as the California Laurel Borer.

Letter 17 – Banded Alder Borer

Strange Bug in LA
Location: LA – Hills
July 13, 2011 7:47 pm
Hi Bugman
My cousin, David, took this picture in his backyard in LA….any idea what it is please? It is so pretty!
Thanks
Michelle
Signature: Michelle

Banded Alder Borer

Dear Michelle,
We wish your photo had a higher resolution, but we are posting it anyway because this is our first report this year of a Banded Alder Borer,
Rosalia funebris, one of the loveliest North American beetles.  You can find much information on the Banded Alder Borer in our archives by using our search engine.

Letter 18 – Banded Alder Borer

Banded Alder Borer Beetle
Location: Whidbey Island Washington
July 19, 2011 1:06 am
I took this picture on Whidbey Island, WA. near the beach. I did some research and found the name, thought you would like this picture.
Signature: Christina

Banded Alder Borer

Hi Christina,
The last image we received of a Banded Alder Borer was not of the greatest resolution, and we are very happy that you have supplied us with a recent high quality image.

Letter 19 – Banded Alder Borer

Banded Alder Borer
Location: Winnemucca, NV
August 8, 2011 12:26 am
Taken at water canyon in Winnemucca, NV.
Signature: Steve

Banded Alder Borer

Hi Steve,
Thank you for sending us your excellent photo of the comely Banded Alder Borer.  Though Nevada is considered part of the normal range for the Banded Alder Borer, we believe this is the first example we have received from Nevada.

Letter 20 – Banded Alder Borer

Interesting beatle
Location: Sechelt, BC.
August 20, 2011 3:00 pm
I took this photo in Sechelt BC.
It looked about 2-3 inches long and just sat there.
I’m very interested in what it is.
Thank You.
Signature: Nathan

Banded Alder Borer

Hi Nathan,
We never tire of posting nice photos of Banded Alder Borers.  In our opinion, they are the most attractive North American beetle.

Letter 21 – Banded Alder Borer

Monochrome Beetle
Location: Bremerton, Washington
August 24, 2011 10:47 pm
Dear Bugman,
I walked out my front door one cool September evening, and found this curious bug sitting on the walkway. I thoroughly enjoyed the coloring and and shape of the bug, so I took a picture. Now I find myself very curious as to what kind of beetle this is. Any information you could give me would be greatly appreciated.
Signature: Stephen

Banded Alder Borer

Hi Stephen,
We almost didn’t look at your request because we have more mail than we can handle and we choose by title. 

Monochrome means one color and we had visions of this being an out of focus image of a brown beetle found in the kitchen cupboard, so we were pleasantly surprised when we opened the digital photo file. 

This beauty is a Banded Alder Borer, however, in California it is known as the California Laurel Borer.

Letter 22 – Banded Alder Borer

Zebra with antenna!?
Location: Portland, OR.
August 29, 2011 11:30 pm
Hello bugman,
I nearly stepped on this guy as I crossed the street in Portland, OR. At first I thought it was a plastic toy and someone was playing a joke on me.

I bent near and saw it twitch a bit and knew it was real and just had to snap a picture or two.
This looks like it fell out of a plane from some tropical exotic rain forest.
Signature: I see stripes

Banded Alder Borer

Dear I see stripes,
In our opinion, the Banded Alder Borer is the most beautiful North American Beetle.

Letter 23 – Banded Alder Borer

Zebra Bug?
Location: Third Creek, Idaho
September 6, 2011 2:27 pm
We saw two of these flying bugs in SE Idaho over the Labor Day weekend. What are they?
Signature: Cathy Rose

Banded Alder Borer

Hi Cathy,
Because of its striking markings and its elegant shape, the Banded Alder Borer is our favorite North American Beetle.

Letter 24 – Banded Alder Borer

Is this a “Banded Alder Beetle”?
I took this photo while backpacking in the East Fork of the San Gabriel river of southern california 2 weekends ago (7/30/05 to be exact). After some web searching, it appears to be the “Banded Alder Beetle” although the marking aren’t exactly the same.

Also, this particular area exhibited much forest devastation due this past winter’s record rainfall and storm damage so i’m figuring they’re feeding on the “dead alders”… Do you agree?
Thanks
Brent Mann

Hi Brent,
There is always some degree of individual variation in the markings within a species. This is a Banded Alder Borer, Rosalia funebris, and the markings are very similar to the photograph in our copy of Hogue’s Insects of the Los Angeles Basin.

The larvae feed on dead wood of a variety of hardwood trees including alder and ash as well as occasionally eucalyptus and live oak. They are also sometimes attracted to paint fumes. Your theory is possible.

Letter 25 – Banded Alder Borer

Can you identify this zebra bug for us?
Having trouble finding out what this but is from a internet search. didn’t know if you might have time to tell me what it is. thanks in advance
Karen Hiller

Hi Karen,
The Banded Alder Borer is also called the Laurel Borer in Southern California.

Letter 26 – Banded Alder Borer

What is it?
Hi,
I stumbled across your site while trying to figure out what this bug is. I’ve lived in Olympia, WA for 12 years and I’ve never seen this bug before, then yesterday, there were 3 of them on the wall outside my office. Can you tell me what it is? Thanks.
Michael

Hi Michael,
This is the second Banded Alder Borer photo we posted this week.

Letter 27 – Banded Alder Borer

type of beetle
Please help me identify a type of beetle (?) about two inches long with antennae about the same length, black & white bands on body and antennae and spot of red on head and ends of antennae.

There were six of them on a garbage can in Pasadena, CA. Have never seen them before. I have attached a photo taken by my son on whose property the beetles were seen.

The Banded Alder Borer is a native of the Los Angeles area. According to Charles Hogue: “Adults may be attracted to the volatizing esters in fresh paint.” Did someone throw paint cans out in the garbage instead of taking them to a hazardous waste depository?

Letter 28 – Banded Alder Borer

Look at this!
I saw this bug flying outside my place of business and I had never seen anything like it before. It is quite large for a flying bug in my area. After some online research, I discovered that it could be an Alder-Boring Longhorn Beetle.

The related info stated that it is native to the Northern Cascades. I captured it in Los Angeles! If it is an Alder-Boring Longhorn Beetle, what is it doing way down here?
Thanks Bugman!
Mike

Hi Mike,
This is indeed a Banded Alder Borer, Rosalia funebris. Here is what Charles Hogue writes in his wonderful book Insects of the Los Angeles Basin:

“Although the species is also popularly known as the California Laurel Borer, it does not use Caulifornia Laurel (Umbellaria species) as a primary host.

It is normally noticed resting on the dead trunks of its host trees, which are alder, ash and other hardwoods. In the basin it sometimes infests Coast Live Oak and eucalyptus.”

Letter 29 – Banded Alder Borer

( SECOND E-MAIL) to share our magnificant hand painted bug! : ) Thanks!!
Hello Bugman,
We found this amazing bug on the wood pile the other day. It is quite large the body is apx. 2- inches long with as you can see, very long antenna! It looked like it was hand painted, quite beautiful!!

We live in Western Washington close to Seattle and in all our years working in the woods we have never seen anything like this. We ran across your wonderful website and we were hoping you could help us identify what kind of critter we have here!

We were also wondering if it is from this area or somewhere else? Thank-you so much for taking the time to help us out during such a busy time for you, we really appreciate it.
Sincerely,
Debbie Helland

Hi Debbie,
We hope our readership does not take it personally that we are unable to answer every letter. We cannot even open every letter. Thanks for your patience and persistance. This is a Banded Alder Borer, and it is native.

Letter 30 – Banded Alder Borer

Subject: Zebra Stripped Bug
Location: Pacific Northwest, Port Angeles, WA
September 8, 2012 10:36 am
I found this beautiful guy resting on a shovel handle in my yard. He caught my eye as I walked by, due to his size and color. He seemed to be very docile as we moved the shovel around to get a good shot. Nothing seemed to disturb him much.

The only movement, a little twitching of his long feelers, which went from completely horizontal to a little arched (as shown in photos).

You will be able to determine the size of my friend, while in one of the photos I am holding a quarter next to him. Thanks for what help you can give me.
Signature: Susan

Banded Alder Borer

Dear Susan,
Because of its beautiful shape, elegant antennae and bold, achromatic markings, our editorial staff finds the Banded Alder Borer,
Roslalia funebris, to be the most beautiful North American Beetle. 

Your photo really does it justice.  The Banded Alder Borer is a western species and in California it is also called the California Laurel Borer.

Letter 31 – Banded Alder Borer

Subject: Black and white
Location: Healdsburg, SONOMA CTY, CA.
July 2, 2013 8:30 pm
We found this black and white insect on a wall in Healdsburg, SONOMA CTY, CA. Can you help identify it?
Signature: DOMINICVS

Banded Alder Borer
Banded Alder Borer

Dear DOMINICVS,
This is a Banded Alder Borer or California Laurel Borer, and we believe it is one of the handsomest North American beetles.

I REST ADMIRED AND REMAIN GRATEFUL FOR YOUR IMMEDIATE AND ACCURATE RESPONSE!
I checked the name and now wonder why it has also the ‘funebris’ in its name….
Is it killing its mate or bringing bad stings?
Warmest regards.
DOMINICVS

Hi again DOMINICVS,
Though we do not know why “funebris” was chosen as its scientific species name, but we can assure you that Banded Alder Borers do not kill their mates, nor do they sting. 

They do have strong jaws and might give a painful pinch if carelessly handled.

Letter 32 – Banded Alder Borer

Subject: Possible Longhorn beetle?
Location: Provo, Utah
July 22, 2013 12:33 am
My sister sent me these pictures yesterday for me to try to identify them. I have never seen this insect before in CO, but it reminds me of Longhorn beetles
Signature: Jake Schafer

Banded Alder Borer
Banded Alder Borer

Dear Jake,
We love this photo.  It is so quirky.  This distinctive insect is a Banded Alder Borer.

Letter 33 – Banded Alder Borer

Subject: Straight out of a Tim Burton movie!
Location: Inland Empire, Southern Caifornia
March 23, 2014 12:24 pm
Ok, so i found this crazy looking bug one day. It was just sitting on the door of a store. It was late June of last year in Southern California. There are some fields close to this shop. Please help me identify this! It still haunts my nightmares!
Signature: Christy

Banded Alder Borer
Banded Alder Borer

Hi Christy,
The Banded Alder Borer,
Rosalia funebris, is sometimes called the California Laurel Borer.

Letter 34 – Banded Alder Borer

Subject: Beautiful Beatle
Location: Willamette valley Oregon
August 23, 2015 8:22 am
I saw this guy just outside Wilhelmina Oregon ( Central Coast area) 1 1/2 inch long 8/22/15
Signature: Walt

Banded Alder Borer
Banded Alder Borer

Dear Walt,
We agree that the Banded Alder Borer is a beautiful beetle.

Thank you very much, you have a fascinating website . I was surprised to get a response so quickly !
Thanks,Walter

Letter 35 – Banded Alder Borer

Subject: Looks like something from Beetlejuice
Location: Lake Cowichan — Vancouver Island — British Columbia Canada
July 17, 2016 11:02 am
I took this photo in Lake Cowichan BritishColumbia on Vancouver Island
The bug was on our gate have lived on the island all my life 57 years never seen anything like it
Find it quite stunning to look at cant believe even the antenna are striped as well
Signature: Debbie Shaughnessy

Banded Alder Borer
Banded Alder Borer

Dear Debbie,
In our opinion, the Banded Alder Borer is one of the prettiest North American beetles.

Letter 36 – Banded Alder Borer

Subject: What’s that bug?
Location: Idaho City, Idaho
July 23, 2016 7:42 pm
Found in Idaho City in July, beautiful but never seen one before! Could be because I’m from Ohio…
Signature: Meg shap

Banded Alder Borer
Banded Alder Borer

Dear Meg,
If we had to vote today on what we think the most beautiful North American beetle is, our vote would go to the Banded Alder Borer.

Letter 37 – Banded Alder Borer

Subject:  Please identify this bug
Geographic location of the bug:  Northwest Oregon
Date: 08/21/2018
Time: 12:18 AM EDT
Your letter to the bugman:  I found this bug on my sidewalk. I would like it identified as it is the first one I have seen.
How you want your letter signed:  Cliff

Banded Alder Borer

Dear Cliff,
This gorgeous beetle is a Banded Alder Borer,
Rosalia funebris.

Letter 38 – Banded Alder Borer

Subject:  Need Insect identified
Geographic location of the bug:  Shoreline WA, Boeing Credk Park
Date: 08/18/2021
Time: 06:59 PM EDT
Your letter to the bugman:  Just curious what this might be.  It was on a dead log in Boeing Creek Park in Shoreline
How you want your letter signed:  Lesley Bell

Banded Alder Borer

Dear Lesley,
This gorgeous beetle is a Banded Alder Borer.

Thanks Daniel!  It sure is a striking beetle for sure.  I had never seen one before and am happy to know what kind of beetle it is!

28 thoughts on “Banded Alder Borer: Essential Facts & Tips for Pest Control”

    • The Banded Alder Borer is a Longhorned Borer Beetle in the family Cerambycidae. The strong jaws are used by the adult to chew their way to the surface of the wood they fed in as a larva. They are not poisonous, however, the bite of some Longhorn species can be quite painful.

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  1. I work in Hillsboro, Oregon. Our facility has been undergoing repainting the last week. I saw these (for the first time in my life) on Tuesday. Further reinforcement for the comment by Charles Hogue 🙂

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  2. Just saw one of these Banded Alder Borer in West Alton, Missouri at the Riverlands Migratory Bird Sanctuary. Impressive looking bug! I’ve never seen this bug before today.

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    • Are you certain you saw a Banded Alder Borer? According to BugGuide, they have not been reported east of Utah, and Missouri is considerably east of Utah. There are many other members in the family that superficially resemble the Banded Alder Borer, however it is quite a distinctive species. We wish you had a photo to document the sighting.

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  3. I have no photo, but definitely saw a Banded Alder Borer July 5, 2014 in Wrightwood, CA (Southern CA mountain area, 6200 ft altitude, mixed pine/oak forest, part of Angeles National Forest).

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  4. We just found one of these in some older logs in our field. We took pictures but can’t get them to post here.
    We live near Port Orchard, Wa.

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  5. I once saw a similar bug to this in Clearlake calif. The body was about 4 inches long and the antenna was about 6 inches long. The body looked thicker/rounder though. Similar markings. It was longer in total than my hand. It was in a restaurant, and this bug walked out of the kitchen, casually walked thru the restaurant, and exited out the front door. A very impressive intimidating bug. Nobody volunteered to help the bug off the premises. All were happy when it exited. No word on what the bug had for lunch. Thanks for posting the pics. I’ve been curious all these years.

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  6. It’s very bug landed on me in the Sierras of California by Hume Lake. Scared the stuff out of me ! I was practically raised in our mountains every year camping but never have I seen this bug before!!! It was huge and flew and landed right on my leg ! Hahaha.. Don’t worry, I put him on a tree, perfectly healthy when I walked away .

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  7. Just came across one in West Seattle along SW Jacobson. Really grateful for your website — I was able to identify it right away. Strikingly beautiful.

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  8. I also found a bug with this same exact markings I live in Roseburg Oregon. I was just curious what do these insect eat? Because I’m sure hoping it’s not my flowers!

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    • According to BugGuide: “Larvae feed in dead hardwood trees: maple, alder, oak, willow, etc” and there is no information on adult feeding habits, indicating they are probably unknown. If the adults ate cultivated plants, there would surely be notice of that. In our mind, your flowers are safe.

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  9. I just had an encounter with one for the first time! I was startled but we put it outside. What a beautiful bug.

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