Cedar Beetle: All You Need to Know for a Bug-Free Garden

The Cedar Beetle is a fascinating insect that has captured the attention of many.

These beetles, often found in coniferous forests, play an important role in the ecosystem.

They aren’t only intriguing to researchers but also to homeowners and gardeners who may encounter these creatures on their properties.

One notable feature of Cedar Beetles is their ability to bore into wood.

This can sometimes cause issues for homeowners, as these beetles may target trees or wooden structures on the property.

Male Cedar Beetle

On the other hand, their wood-boring nature can also help break down dead trees, allowing for decomposition and nutrient recycling in the environment.

In this article, we’ll dive deeper into the world of Cedar Beetles, exploring their life cycle, behaviors, and impact on our world.

We’ll also discuss ways to manage them and provide tips on how to coexist with these fascinating creatures.

So, let’s embark on a journey to learn all about the Cedar Beetle and the role it plays in our environment.

Cedar Beetle Overview

Classification and Species

The Cedar Beetle, belonging to the kingdom Animalia, class Insecta, and order Coleoptera, is part of the family Callirhipidae, and subphylum Hexapoda.

One of the most well-known species within this family is the Japanese Cedar Longhorned Beetle (Callidiellum rufipenne)1.

These beetles are also known as Cicada Parasite Beetles due to their parasitic relationship with cicadas2.

Physical Characteristics

Cedar Beetles showcase some unique features, and below are their most notable characteristics:

  • Body length: Approximately 5/8 inch long1
  • Males are deep blue to black in color1
  • Males have antennae longer than their bodies1
  • Hardened wing covers, known as elytra3

A comparison of Cedar Beetles’ appearance to Western Pine Beetles:

CharacteristicCedar BeetleWestern Pine Beetle
ColorDeep blue to blackReddish-brown
AntennaeLonger than their bodies (males)Shorter
SizeAbout 5 / 8 inches longApprox. 6 to 13 mm (1/4 to 1/2 inch) in diameter

Some key characteristics of Cedar Beetles:

  • Deep blue to black color
  • Males have antennae longer than their bodies
  • Roughly 5 / 8 inches in length.

Cedar Beetle Habitat and Distribution

The Cedar Beetle is commonly found in North America and thrives in areas where their preferred wood, cedar, is abundant.

These beetles are commonly connected to cedar trees, as their name implies.

However, they can also be found on other types of wood. One example is the Japanese Cedar Longhorned Beetle, which feeds on Japanese cedar.

Male Cedar Beetle

This species has a distinct appearance, with males being deep blue to black and having antennae longer than their bodies.

In the USA, their distribution can vary among regions. Cedar beetles are more commonly found in places with a dense concentration of cedar trees.

They use these trees for shelter and as a source of sustenance. 

The habitat and distribution of Cedar Beetles can be compared with other wood-boring beetles, such as the Old House Borer.

The Old House Borer is also a long-horned beetle and is known for infesting homes.

It differs from the Cedar Beetle regarding their preferred type of wood and extent of damage caused.

Here is a comparison table between Cedar Beetle and Old House Borer:

Beetle TypePreferred WoodHabitatImpact on Trees/Homes
Cedar BeetleCedar TreesNorth AmericaModerate damage to cedar trees
Old House BorerVariety of wood typesNorth America, Especially in HomesSevere damage to various wood structures

Life Cycle and Behavior

Larval Stage

Cedar beetles have a larval stage that resembles other bark beetle larvae. During this stage, they primarily feed on tree tissues.

The development time for larvae depends on factors such as temperature and food availability. In general, the life cycle of cedar beetles consists of one generation per year.

Larvae characteristics:

  • White to tan color
  • Head capsule
  • Feeds on tree tissues

Adult Stage

Adult cedar beetles are not aggressive tree killers but can cause damage to twigs, branches, and even entire trees.

They usually infest one-seed junipers, as well as ornamental and windbreak plantings of eastern red cedar.

Mating Cedar Beetles

Adult beetle behavior:

One common example of cedar beetle species is the Sandalus niger, or black cedar beetle

Infestation and Damage

Signs of Infestation

Cedar beetle infestations often show the following signs:

  • Small, round entry and exit holes in tree bark
  • Yellowing or browning of foliage
  • Thinning of tree canopy

The beetles bore into trees to lay their eggs, leaving characteristic holes behind.

Impact on Trees

Cedar beetles can cause significant damage to infected trees. Their tunneling activities can:

  • Interrupt the tree’s nutrient and water flow
  • Weaken the tree’s overall structure
  • Lead to branch dieback or total tree death

A comparison between healthy and infested trees:

 Healthy TreesInfested Trees
Foliage colorGreenYellow or brown
Canopy thicknessDenseThin
Bark hole presenceNoYes
Tree structureStrongWeak or brittle

Be mindful of these signs and act fast if you suspect a cedar beetle infestation. Early intervention can help minimize the damage to your trees.

Pest Management and Prevention

Insecticide Alternatives

Cedar beetles can be effectively managed with a few insecticide alternatives. Here are some options:

  • Diatomaceous Earth (DE): A natural powder that can effectively kill cedar beetles by damaging their exoskeleton.
  • Integrated Pest Management (IPM): An environmentally sensitive approach that combines various strategies, using pesticides only as needed.

Effective Vacuuming Techniques

An important part of pest management and prevention is regular and thorough vacuuming. Here are some effective techniques:

  • Targeted vacuuming: Focus on areas where beetles are most commonly found, like carpet edges, baseboards, and closets.
  • Using attachments: Utilize vacuum attachments like crevice tools and brush rolls to access hard-to-reach areas.

For example, vacuuming your carpets near the baseboards, using a crevice tool can help remove larvae and eggs hidden in tight spaces.

Wedge Shaped Beetle

Conclusion

The Cedar Beetle, predominantly found in North America’s coniferous forests, plays a dual role in our ecosystem.

While they assist in decomposition and nutrient recycling, their wood-boring nature can pose challenges for homeowners and gardeners.

Recognizing their unique characteristics, understanding their life cycle, and being aware of their impact is crucial.

By employing eco-friendly management techniques and staying informed, we can coexist harmoniously with these intriguing insects and maintain a healthy, bug-free garden.

Footnotes

  1. Japanese Cedar Longhorned Beetle 2 3 4 5 6 7
  2. Cicada Parasite Beetles 2
  3. Elytra of Beetles

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 – Cedar Tree Borer

 

Subject: new bug Location: Bend Oregon February 21, 2015 11:47 pm this is a new bug all over my house we were on vacations to Thailand for 2 weeks and the day I got back I notice this bug all over the house, is not in the rooms just in the kitchen and the living room! but in the last two hours I saw 5 of them… please help me Signature: Marian
Beetle
Cedar Tree Borer
Hi Marian, We are requesting assistance from Eric Eaton to help identify your beetle. Hi Eric, It looks a bit like a checkered beetle, but the person from Bend Oregon who sent the picture has indicated that significant numbers are appearing inside the home, which makes me wonder if it is a wood borer. Daniel Eric Eaton provides identification:  Cedar Borer Daniel: It is indeed a longhorned woodborer, the Cedar Tree Borer, Semanotus ligneus.  Here’s the Bugguide link: Yes, they are likely emerging from firewood, but potentially from the structure itself, or cedar furniture.  For reasons still unclear, when a beetle larva is trapped inside milled lumber, it frequently extends the life cycle of the larva by years, sometimes decades.  Then, suddenly, beetles are popping out of whatever the lumber was used to build. Eric Eaton Hi Again Marian, Eric Eaton has identified your Cedar Tree Borer, and Bugguide indicates it feeds on “Juniper, Cedar” in the larval stage.  Since you found significant numbers in the home, we are speculating that wood that was infested with larvae resulted in a mass eclosion or emergence.  Perhaps there was some firewood in the home, or perhaps you bought a recent piece of cedar or juniper furniture made with infested wood. Daniel and Eric thank you so much! yes there was so firewood (juniper) inside. Thank you again ! Marian

Letter 2 – Wedge Shaped Beetle, NOT Cedar Beetle

 

Hello again Thanks for the last id.  I have this new insect she is stunning and I would love to know what she is. I have no idea I looked up but could not find any information. thanks Terri Martin Dear Terri, In the future, please use our standard form for submissions which is located by clicking the Ask What’s That Bug? link on our site. Where are you located?  Do you have a dorsal image of this insect’s back?
Probably Cedar Beetle
Wedge Shaped Beetle
Ed. Note:  The small staff of What’s That Bug? does not have the time to try to track down previous submissions to our site from folks who prefer to respond to previous communications from us rather than using our standard form which request certain information and also provides a standard formatting for our postings. Hi again Terri, We took the time to track down your name in our archives, as we are guessing you are the same Terri Martin who submitted an image of Gaurotes cyanipennis for identification in May.  If we are correct, we are then going to assume that this request is also from Baltimore, Ontario.  Because it takes so much additional time to track down previous submissions, we would normally have pitched this request right into the trash, and the only thing that prevented that is that your images are stunningly beautiful, and if we are correct, they are of a male Cedar BeetleSandalus niger, an underrepresented species on our site, though BugGuide has no submissions from Canada.  As we mentioned in our initial response, we wish you had provided a dorsal view.  Additionally, we have contacted Eric Eaton to corroborateour identification. Correction Courtesy of Eric Eaton Dear Daniel: No.  LOL!  Good guess, though, given the angles in these images.  Did you take them?  This is a “wedge-shaped beetle” in the family Ripiphoridae.  Probably Ripiphorus sp., but there are other, similar genera.  They are parasites, in the larval stage, of solitary bees.  Their small size, and the short wing-covers, distinguish them from the cicada parasite beetle you mentioned. Eric author, Kaufman Field Guide to Insects of North America http://bugeric.blogspot.com/
Wedge Shaped Beetle
Wedge Shaped Beetle
Thanks Sorry Daniel I was so excited seeing this guy.  I do have a back shot I will attach here. I found it in Courtice, Ontario  (Courtice Arena)  Prestonvale st. I will use the correct process next time. Thanks agian Terri
Wedge Shaped Beetle
Wedge Shaped Beetle
Thanks so much for providing this dorsal view of a Wedge Shaped Beetle.  Eric Eaton provided us with a corrected identification.  We want to thank you again for submitting such excellent images.
Wedge Shaped Beetle
Wedge Shaped Beetle

Letter 3 – Cedar Tree Borer, we believe

 

Subject: What is this bug? Location: Northern Maine woods January 13, 2017 8:59 am Hi , these bugs have just started randomly showing up in our newly built hunting/fishing home . It was stick built with knotty pine on the inside and spray foam insulation., and pine siding. We started building in may of 2015 and still have a painted plywood floor but other then that it is quite finished. It is located in Northearn Maine and we have not seen these bugs until this past November. Any help in identifying it would be extremely appreciated. Thank you Signature: Pete
Cedar Tree Borer, we believe
Dear Pete, Was any Cedar used in the construction of your new home?  This looks to us, based upon this BugGuide image, to be a Cedar Tree Borer, Semanotus ligneus.  According to BugGuide: “hosts: Thuja, Cupressus, Juniperus.”  The appearance beginning in Novemnber may coincide with indoor heating being turned up higher.  If the beetle larvae or pupae were in milled lumber, they may have emerged with the increased heat.  They may also have been introduced in firewood.  If they were dormant in wood used in the construction of your home, you may continue to see them in subsequent years, but the good news is that they will not continue to breed in your home. Well that does explain things. We did put up som cedar boards on a few interior walls.   So happy to hear that they won’t reproduce. Thank you for your reply.

Letter 4 – Male Cedar Beetle

 

Subject:  Black beetle with fun antennae Geographic location of the bug:  Kansas City Date: 10/09/2017 Time: 07:18 PM EDT Found this little beetle on my outside window. I love the antennae. Could you tell me please what this is? How you want your letter signed:  TW
Male Cedar Beetle
Dear TW, This is a male Cedar Beetle or Cicada Parasite Beetle, Sandalus niger, which we identified on BugGuide.  According to BugGuide, they are present “mostly: Sept-Oct.”  Of the genus, BugGuide notes:  “antennae flabellate in males, serrate in females” and flabellate is an entomological term to describe fanlike antennae.
Male Cedar Beetle
A reader comments. Subject (please be succinct, descriptive and specific):  Cedar Beetle October 12, 2017 Through your site I discovered that I had found a Cedar Beetle. My husband and I are in Littlefield Texas for a few months for a job and this is where I found it. A few days later I went for a walk and saw a large amount of them flying around a tree in our backyard. It was very strange as there seemed to be only one female and the rest were males all trying to mate with her. I have several pictures and videos of them. If you are interested in seeing them I would be happy to send them to you. Also, the following day I was digging to plant a bush and dug up a female. She seemed fully formed but not quite ready for the outside world yet. I wasn’t sure if I should bury her or not so I put her under the bush I planted. A short time later, I saw two males buzzing around looking for her. Thanks for your time reading this and the work you put into this site! Your Name:  Jacqueline Hook

Letter 5 – Male and Female Cedar Beetles

 

Subject: Fuzzy antenna beetle Location: Lorain, Ohio September 23, 2014 12:34 pm I found this beetle flying around my porch. There was another one (I’m guessing female, due to its lack of fan-like antenna) sitting on the side of my house. The back of their abdomen is orange. It is currently early autumn. Signature: Candice
Male Cedar Beetle
Male Cedar Beetle
Dear Candice, We are very excited about your submission.  WE believe you have documented images of both a male and female Cedar Beetle, Sandalus niger, an identification we verified on BugGuide.  According to BugGuide, they are found “Mostly: Sept-Oct” and “Larvae probably feed on Cycada nymphs. Adults very short lived.”
Female Cedar Beetle
Female Cedar Beetle
Female Cedar Beetle
Female Cedar 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 – Cedar Tree Borer

 

Subject: new bug Location: Bend Oregon February 21, 2015 11:47 pm this is a new bug all over my house we were on vacations to Thailand for 2 weeks and the day I got back I notice this bug all over the house, is not in the rooms just in the kitchen and the living room! but in the last two hours I saw 5 of them… please help me Signature: Marian
Beetle
Cedar Tree Borer
Hi Marian, We are requesting assistance from Eric Eaton to help identify your beetle. Hi Eric, It looks a bit like a checkered beetle, but the person from Bend Oregon who sent the picture has indicated that significant numbers are appearing inside the home, which makes me wonder if it is a wood borer. Daniel Eric Eaton provides identification:  Cedar Borer Daniel: It is indeed a longhorned woodborer, the Cedar Tree Borer, Semanotus ligneus.  Here’s the Bugguide link: Yes, they are likely emerging from firewood, but potentially from the structure itself, or cedar furniture.  For reasons still unclear, when a beetle larva is trapped inside milled lumber, it frequently extends the life cycle of the larva by years, sometimes decades.  Then, suddenly, beetles are popping out of whatever the lumber was used to build. Eric Eaton Hi Again Marian, Eric Eaton has identified your Cedar Tree Borer, and Bugguide indicates it feeds on “Juniper, Cedar” in the larval stage.  Since you found significant numbers in the home, we are speculating that wood that was infested with larvae resulted in a mass eclosion or emergence.  Perhaps there was some firewood in the home, or perhaps you bought a recent piece of cedar or juniper furniture made with infested wood. Daniel and Eric thank you so much! yes there was so firewood (juniper) inside. Thank you again ! Marian

Letter 2 – Wedge Shaped Beetle, NOT Cedar Beetle

 

Hello again Thanks for the last id.  I have this new insect she is stunning and I would love to know what she is. I have no idea I looked up but could not find any information. thanks Terri Martin Dear Terri, In the future, please use our standard form for submissions which is located by clicking the Ask What’s That Bug? link on our site. Where are you located?  Do you have a dorsal image of this insect’s back?
Probably Cedar Beetle
Wedge Shaped Beetle
Ed. Note:  The small staff of What’s That Bug? does not have the time to try to track down previous submissions to our site from folks who prefer to respond to previous communications from us rather than using our standard form which request certain information and also provides a standard formatting for our postings. Hi again Terri, We took the time to track down your name in our archives, as we are guessing you are the same Terri Martin who submitted an image of Gaurotes cyanipennis for identification in May.  If we are correct, we are then going to assume that this request is also from Baltimore, Ontario.  Because it takes so much additional time to track down previous submissions, we would normally have pitched this request right into the trash, and the only thing that prevented that is that your images are stunningly beautiful, and if we are correct, they are of a male Cedar BeetleSandalus niger, an underrepresented species on our site, though BugGuide has no submissions from Canada.  As we mentioned in our initial response, we wish you had provided a dorsal view.  Additionally, we have contacted Eric Eaton to corroborateour identification. Correction Courtesy of Eric Eaton Dear Daniel: No.  LOL!  Good guess, though, given the angles in these images.  Did you take them?  This is a “wedge-shaped beetle” in the family Ripiphoridae.  Probably Ripiphorus sp., but there are other, similar genera.  They are parasites, in the larval stage, of solitary bees.  Their small size, and the short wing-covers, distinguish them from the cicada parasite beetle you mentioned. Eric author, Kaufman Field Guide to Insects of North America http://bugeric.blogspot.com/
Wedge Shaped Beetle
Wedge Shaped Beetle
Thanks Sorry Daniel I was so excited seeing this guy.  I do have a back shot I will attach here. I found it in Courtice, Ontario  (Courtice Arena)  Prestonvale st. I will use the correct process next time. Thanks agian Terri
Wedge Shaped Beetle
Wedge Shaped Beetle
Thanks so much for providing this dorsal view of a Wedge Shaped Beetle.  Eric Eaton provided us with a corrected identification.  We want to thank you again for submitting such excellent images.
Wedge Shaped Beetle
Wedge Shaped Beetle

Letter 3 – Cedar Tree Borer, we believe

 

Subject: What is this bug? Location: Northern Maine woods January 13, 2017 8:59 am Hi , these bugs have just started randomly showing up in our newly built hunting/fishing home . It was stick built with knotty pine on the inside and spray foam insulation., and pine siding. We started building in may of 2015 and still have a painted plywood floor but other then that it is quite finished. It is located in Northearn Maine and we have not seen these bugs until this past November. Any help in identifying it would be extremely appreciated. Thank you Signature: Pete
Cedar Tree Borer, we believe
Dear Pete, Was any Cedar used in the construction of your new home?  This looks to us, based upon this BugGuide image, to be a Cedar Tree Borer, Semanotus ligneus.  According to BugGuide: “hosts: Thuja, Cupressus, Juniperus.”  The appearance beginning in Novemnber may coincide with indoor heating being turned up higher.  If the beetle larvae or pupae were in milled lumber, they may have emerged with the increased heat.  They may also have been introduced in firewood.  If they were dormant in wood used in the construction of your home, you may continue to see them in subsequent years, but the good news is that they will not continue to breed in your home. Well that does explain things. We did put up som cedar boards on a few interior walls.   So happy to hear that they won’t reproduce. Thank you for your reply.

Letter 4 – Male Cedar Beetle

 

Subject:  Black beetle with fun antennae Geographic location of the bug:  Kansas City Date: 10/09/2017 Time: 07:18 PM EDT Found this little beetle on my outside window. I love the antennae. Could you tell me please what this is? How you want your letter signed:  TW
Male Cedar Beetle
Dear TW, This is a male Cedar Beetle or Cicada Parasite Beetle, Sandalus niger, which we identified on BugGuide.  According to BugGuide, they are present “mostly: Sept-Oct.”  Of the genus, BugGuide notes:  “antennae flabellate in males, serrate in females” and flabellate is an entomological term to describe fanlike antennae.
Male Cedar Beetle
A reader comments. Subject (please be succinct, descriptive and specific):  Cedar Beetle October 12, 2017 Through your site I discovered that I had found a Cedar Beetle. My husband and I are in Littlefield Texas for a few months for a job and this is where I found it. A few days later I went for a walk and saw a large amount of them flying around a tree in our backyard. It was very strange as there seemed to be only one female and the rest were males all trying to mate with her. I have several pictures and videos of them. If you are interested in seeing them I would be happy to send them to you. Also, the following day I was digging to plant a bush and dug up a female. She seemed fully formed but not quite ready for the outside world yet. I wasn’t sure if I should bury her or not so I put her under the bush I planted. A short time later, I saw two males buzzing around looking for her. Thanks for your time reading this and the work you put into this site! Your Name:  Jacqueline Hook

Letter 5 – Male and Female Cedar Beetles

 

Subject: Fuzzy antenna beetle Location: Lorain, Ohio September 23, 2014 12:34 pm I found this beetle flying around my porch. There was another one (I’m guessing female, due to its lack of fan-like antenna) sitting on the side of my house. The back of their abdomen is orange. It is currently early autumn. Signature: Candice
Male Cedar Beetle
Male Cedar Beetle
Dear Candice, We are very excited about your submission.  WE believe you have documented images of both a male and female Cedar Beetle, Sandalus niger, an identification we verified on BugGuide.  According to BugGuide, they are found “Mostly: Sept-Oct” and “Larvae probably feed on Cycada nymphs. Adults very short lived.”
Female Cedar Beetle
Female Cedar Beetle
Female Cedar Beetle
Female Cedar Beetle

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.

3 thoughts on “Cedar Beetle: All You Need to Know for a Bug-Free Garden”

  1. Do these bugs pose any problems or dangers, other than just being pests. I have had an influx of them in the past few days and we also use juniper firewood.

    Reply
    • The male Cedar Beetle has much more developed antennae. You may send your video by using our standard submission form that can be reached by clicking the Ask WTB? icon on our site.

      Reply

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