Not Every Long Horned Beetle in Ontario is an Asian One

For a few brief glorious months, Canada was declared to be free of any traces of Asian Long Horned Beetles after a campaign of many years and more dollars. Then, distressingly, in mid-2013 the announcement was rescinded: a worker near Pearson Airport found a large insect on his car windshield. It was an Asian Long Horned Beetle.  A new quarantine and cleanup began. The government would like you to keep an eye out for these beetles and advise them quickly if you find any. The tricky part is not every Long Horned Beetle in Ontario is an Asian one.

Why are They Called Long Horned Beetles?

It’s not the best name, admittedly, because unlike Rhino beetles, these ones have no “horns” at all. What they do have is startlingly long antenna. Like this one:

Photo of White Spotted Sawyer Antenna On NaturalCrooksDotCom

What’s the Most Common Long Horned Beetle in Ontario

There are a surprising number of types of Long Horned Beetles. Well, surprising to me because I’ve rarely seen any.

The most common native Ontario type seems to be the White Spotted Sawyer. “Sawyer” is used in its original meaning as one who saws wood. According to the Royal Alberta Museum website, “The larvae make enough noise when chewing their way through the wood that it sounds like a distant saw, hence the name.” (Apparently they sometimes snack on log cabins!)

How Can I Tell If My Find is a White Spotted Sawyer?

Your best bet is to get confirmation from an etymologist. However, there is one noted field mark: According to the scutellum is white. “(Scutellum is the little triangle at the front of the elytra, or wing covers.)”

If you squint at my photo closely, you’ll see this small white triangle sort-of in the centre of the “neck.”

Photo of White Spotted Sawyer Scutellum on NaturalCrooksDotCom

The number of other white spots can vary widely. It can have only the scutellum spot or it can be heavily dappled.

What Do White Spotted Sawyers Eat?

Again, according to, the larvae “excavate galleries in coniferous trees, often after they are damaged by a fire, storm, etc.” Balsam fir, spruces and white pines are common hosts.

We’ve actually seen the work the grubs do and it’s both impressive and kind of gross. A particularly bad stormed felled a 90-foot-plus white pine near my relatives’ cottage. While sawing it up, my strong-armed relative found the chambers bored out by the larvae. The larvae themselves were large and thriving.

According to the Natural Resources Canada website adults can damage young twigs on healthy trees by feeding on the tender bark. The larvae are both “phloeophagous” and “xylophagous” because they feed on both phloem and woody tissues. The tunnels from the young can damage wood cut for lumber. Foresters need to take precautions to avoid having cut but not used logs damaged by the beetles.

Photo of White Spotted Sawyer on NaturalCrooksDotCom

The NRC lists the host trees as

  • balsam fir
  • black spruce
  • eastern white pine
  • jack pine
  • red pine, and
  • white spruce

You can see photos of the larvae at

Are White Spotted Sawyers Dangerous?


They can bite but according to the Royal Alberta Museum website they rarely do and they don’t secrete any poisons or weird digestive enzymes they just pinch.

Odd Fact Courtesy of BugGuide.Net

Apparently, White Spotted Sawyers are attracted to the scent of bitumen in the Alberta oil sands because it smells similar to diseased and damaged conifers. The beetles are attracted to the scent when looking for a place to lay their eggs.

Related Reading

Join In
Have you ever seen a Long Horned beetle? Did it startle you enough to spill your lemonade, like I did? Please share your experiences with a comment.

19 thoughts on “Not Every Long Horned Beetle in Ontario is an Asian One

  1. The white Sawyers are all numerous at my cottage on Gold Lake…tornado downed 27trees last year and you can hear them chew the wood.

    • Eek! I’m glad to hear nature’s cleanup crew is at work but I don’t think I’d be too happy to have to listen to the chomping. When the gypsy moth’s ate their way through the canopy near Sharbot Lake, you could not only hear the chewing but their waste literally rained down from the treetops all day long. So you have my extreme sympathy.

      I also hope no one was hurt by the tornado!

      Thank you for sharing.

  2. We had one of these sitting on our deck (which is not wood) yesterday and after looking at it closely to find out what it was, a chipmunk came along and ate him. Never knew chipmunks ate beetles, but it seemed to be a great delicacy!

  3. I should clarify that it was us that looked at it closely as we had never seen one. The chipmunk pounced on it immediately!

    • That’s amazing! I wouldn’t know they eat them either–you can’t get more proof than watching it happen. Thanks for sharing your sighting!

  4. I saw one of these on my front wooden patio yesterday. Could this have something to do with the loud knocking noise I hear at night?

    • It’s possible but I haven’t read about them making a knocking noise, only a sort of squeaky sound. Sorry I can’t be more help–if you think something is damaging your porch, you might want to call a pest control company. They may have a better idea what might be knocking. I hope it’s nothing serious!

  5. Had one fly into my car back seat yesterday. Didn’t know what ihad flown in until it was walking up the arm rest beside me. We see then frequently but this one was HUGE! I couldn’t stop fast enough to get rid of it!!

  6. My boys were having hotdogs this afternoon when my six year old exclaims, “Mommy, there’s a cockroach on the chair!!!” “Maxime, we do not have cockroaches.” “Well what is thaaaaat?!” So we caught him, checked him out in our bug-abode and then did a quick search. Thanks for your thorough page! They love to learn about bugs just like their mom. :)

  7. There are lots of Long Horned Beetles in Thompson , Manitoba. Ton’s of them by the Vale smelter . There bite is very painful.

  8. We have just killed 12-15 of these bugs on our back deck.. We might be attracting them because we just sprayed a wasps nest over the back of the deck with an oily smelling rid of wasps but may have attracted bugs. so bad we cannot sit outside and enjoy nice weather they have also got into my hair and landed on my back. I have been told they bite viciously and literally take out skin.

    • I haven’t personally met anyone who has been bitten by one, so I hope they’re wrong about what kind bit them. And I’m very sorry you have so many arriving! Hopefully they will move on soon.

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