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 Then, distressingly, in mid-2013 the announcement was rescinded: a worker near Pearson Airport found a large insect on his car windshield.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 BugGuide.net 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 BugGuide.net, 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 http://tidcf.nrcan.gc.ca/en/insects/factsheet/900

Are White Spotted Sawyers Dangerous?

No.

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.

39 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!

  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 spray..got 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.

    • Realize that wasps also eat lots of insects too. So, unless they’re a nuisance, I leave them around to do their thing. :)

  9. These beetles bite is extrordinarily painful! Yes they are in Alberta, I have shoed them out of my vehicle, one was riding around on my exea back like an episode of the cartoon south park in the save the rainforest episode(hilarious) but seriously their bite is awful so kill them on sight with your shoe if nothing else is on hand!

  10. Oh yeah they bite…I just got bit 15 minutes ago and let me tell you they bite hard and you feel it…lol.

  11. I had one land on my shoulder but I heard it flying and land before I seen it when I sat in my truck. Then I did the crazy dance trying to hit it off my shoulder with my truck keys. Man their wings sound crazy loud when they land on you. My granddaughter couldn’t stop laughing at me as I danced around.

  12. They get really big, come out when it’s hot out and their bite can take a chunk of skin off and make you bleed

  13. I saw one that looked like the Asian beetle after I cut down a spruce trees today in Parry Sound. The tree died in 6 months and was very healthy. What should I look for to confirm if it was a Sawyer? Is there anything to do stop them again from attacking another tree?

  14. Just found one of these in my bedroom, yuck 🤢 I heard a “thwap” sound over by the dresser and almost had a heart attack when I saw it on the wall. Caught it using a clear plastic cloche left from protecting plants during the chilly June, slid the newspaper under it then carried it outside. I’m petrified to release it in case it flies back inside so I’ll just wait until morning and hope it’s dead. I don’t usually mind bugs but this was a bit too much! I’m in Oakville btw

  15. Chillin’ in the livingroom, a MASSIVE (about 2″ without the antennai) bug crawls up the outside of the window. I’m like, “Woah! Check out that awesome bug… I feel like I should go out and snap a pic…” I didn’t. 30min later loud flapping and I look up to see the beast perch right above my head on the bookshelf. Got some pics, let it out and had to find out what it was… thx for this cool thread.

  16. Asian long-horned beetle (ALHB) is an invasive forest pest with no natural enemies in North America that attacks nearly all broadleaf trees, with native Maples being the preferred host. It was introduced to North America in the 1990’s through untreated wooden shipping pallets. Adults lay their eggs in hardwood trees, and larvae then tunnel through the living tissue of the tree stopping the flow of water and nutrients, killing it. There have been very few sightings of ALHB in Ontario and it is important to be on the lookout for this dangerous invader. Several native non-harmful beetles can be easily confused with ALHB, so take a close look at how to identify this beetle listed below.

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