What's That Bug? does not endorse extermination

Can you tell me what kind of bug this is?
August 10, 2009
Just got back from a camping trip in Teller County Colorado and this bug landed on my leg. I have searched high and low on the web for pics of this insect.
Please help, Thanks Jon and Family

Giant Wood Wasp

Giant Wood Wasp

Dear Jon and Family,
This is a Giant Wood Wasp, Urocerus gigas.  It is also called the Greater Horntail Wasp or the  Yellow Horned Horntail.  According to BugGuide:  “Range Introduced, originally from Europe and Asia.  Habitat  Attacks five or more genera of Pinaceae  Remarks  It tunnels in wood. One of the most dangerous pests of conifers. We will be tagging your post as an Invasive Exotic.

Correction:  August 12, 2009
Not an invasive exotic wood wasp
I was certain that U. gigas the exotic form has yet to be established here in the US.  Upon discussion with our entomologist he is positive it is Urocerus gigas flavicornis (Fabricius) which is a native subspecies.  Colorado is just one of the states that it can be found.   You had me worried there for a minute.  Our cups runith over with exotics as it is like Sirex noctillio.  Great work as always and glad to see you folks have links to get in touch with the proper agencies that handle exotic invasive pests.  I encourage your readers to become aware of exotic invasive pests, report new finds and help protect our resources.
Can’t wait to see your book

What's That Bug? does not endorse extermination

56 Responses to Giant Wood Wasp

  1. LeBunny37 says:

    This giant wood wasp is in Olympia, WA too. Icky bug. My son went camping and brought it home today. I love internet. =D

    • Joey Floyd says:

      Yeah I’m from Tacoma and was camping in the Snoqualmie pass area this summer and one of those things flew into our camp site and freaked everyone out lol.

  2. tamihangstefer says:

    We have these wood wasps in Alaska too. They seem to like to live around the mud.

  3. paulstewart10 says:

    hi all, was just searching to see if i could recognise a wasp i found and it seems to be a greater woodwasp, i live in just outside Dungannon, in co Tyrone, Northern Ireland. can anyone tel me if theese wasps are native to the UK or is this one that got lost.
    Thanks, Paul

  4. Woodwasp says:

    I’ve been looking for this for years. We had one of these things in our Garden Center (at a DIY store, IN THE UK) back in 2003/4. THE WORST Wasp I’ve ever seen!!.

  5. Nick Mc says:

    I found One of these in Ireland last week 10/08/2012
    We were in Lavally, just outside Tuam North of Galway.
    We were cutting trees in a pine forest when one flew at us I batted it away and that was it so I thought.
    The next day down at the house where we moved the logs to a large was as in the picture was buzzing around, as it was so different I wanted to catch it so I gave it a almighty dose of fly spray. After the third dose I got it into a bottle and asked many locals including farmers and gardeners and no one had seen one before.
    Thanks to the web I now know what we caught.
    How dangerous are they?
    Why in Ireland?
    Thanks for reading my waffle.

  6. Just found a giant wood in my girls back garden in belfast

  7. merissa says:

    they are in Colfax Washington too I never seen them before. are they deadly if stung

  8. Lindsay says:

    Found one of these in my yard in Calgary, Alberta Canada. Had never seen one before and was quite alarmed by it’s size and the size of the apparent stinger?

    • Nick McLeish says:

      It loos like it could give a nasty sting but it is actually a protective cover for its Ovipositor which is how it lays its eggs into decaying wood.
      It leaves little 1/2 mm holes like wood worm, after time I do not know how long the new wasp appears leaving a hole up to 5mm.
      If you go onto you tube you will see films of it laying its eggs, that is why people get so close to take pictures as its attached to the wood for a few minutes.

  9. Nick McLeish says:

    I posted last year that we had seen a Giant wood wasp in Ireland last summer 2012

    Well we have been back to Levally Galway Ireland this summer 2013 and have seen more of the Giant Wood wasp.

    The strange thing is when we have shown our pictures or described it to the locals nobody has ever seen one.

    They are big and I have found they are silent in flight.

    I did get a couple of pictures of one and through research on the internet found out that the sting looking thing is part of its abdomen and is there to protect the Ovipositor which it drops down at 90 degrees to its body penetrates the wood and lays it eggs through. It leaves a small hole which looks like wood worm. I believe then after time the new wasp emerges and leaves a hole up to 5MM.

    Amazing to watch as it lays its eggs especially when it pushes itself right up to get the ovipositor out of the wood.

    Have a look on You Tube for other peoples postings, one man actually has one on his hand.


  10. Al H. says:

    We have a live maple tree in our front yard and it has about 5 to 10 on it all the time. They are in various stages of laying eggs. The interesting thing is that they seem to die when they are drilled into the tree. There are about 4 or 5 dead ones still hanging on the tree with the ovipositor still stuck in the tree. They look like they are standing up against the tree. Right now there are about 3 crawling around on the tree testing it ( I suppose like a soft spot) . They ave been on the tree for the last three to four days. This is in S.W. Minnesota and it is September 11, 2013. They look very mean. This one has about 7 yellow rings on the body. They seem to have 4 wings (2 pair). I have one in a bottle to observe it. I will release it later.

  11. Dave Malone says:

    One of these landed on me yesterday, scared the hee-bee-gee-bees outta me. I’m located near Louisville Ky. Looks like my Irish Ancestors could of told me what it was. Took most of today to find out what it was

  12. BWHall says:

    We found a giant wood wasp here in Michigan. It was trying to get in my house.
    Thanks to this website, i now know what it is.

  13. John says:

    We have them in south central Alaska….and they do bite…thru very heavy clothing. And they hurt as badly as their looks indicate.
    They are aggressive up here, and will constantly attack until killed.
    My wife was oiling a deck and I had to stand guard with an electric swatter (like a badminton raquet) and killed a dozen or more in less than 30 minutes.
    Dry summers mean trouble as they multiply very effectively in dry summers.

  14. Carla says:

    These have been spotted in my garden too, UK!

  15. Joseph Alberico says:

    I have one of these wood wasp’s in my yard Mohawk n y

  16. SA says:

    Found one in north-central Maryland August 2014. First we’d ever seen.

  17. Chris says:

    Have a bunch of these in my backyard. Here in the Bronx in New York . Couldn’t believe how huge the stingers are on these things. Thanks to your site i was finally able to identify what looked like an ancient creature flying around my yard

    • bugman says:

      What you have mistaken for a stinger is actually the ovipositor of the female. In stinging insects like bees and wasps, the ovipositor is modified into a stinger.

  18. Nick says:

    Have a look at this. More on Youtube.


  19. Intimategems says:

    Recently cut down 1/2 a dead maple tree on my property and these things were buried up to 10 inches inside.

    The tree has thousands of holes in it and I found dozens of these at various stages of development.

    They look very intimidating because of their size and appearance. I took some amazing pictures. I also made a few videos showing them buried throughout parts of the tree. I will try to upload some of the images later onto the web.

    I’m in queens, New York

    • Nick says:

      They do not sting, once the egg is laid it can be 2 years before the wasp comes out.
      People have had them come out of the wood work in their houses due to this.

  20. Adam Green says:

    I’ve just found one of these in Cumbernauld, Scotland, but can’t seem to find much info on them. Are they natives to North america only? Or do they range as far as Scotland/the uk?

  21. Nick says:

    We found them in Tuam Galway Ireland.

  22. David says:

    Just came across a Wood Wasp in Bearsden, Glasgow. We had been cutting trees down and a few days later it appeared as if to survey the area. Huge deep orange in colour but silent. Flew around a cut down tree stump then moves off. First time I had ever came across one!

  23. Kev says:

    I found a giant wood wasp , on my allotment in Market Weighton , YO43

  24. michelle says:

    my son found one today, newport in south wales england

  25. Audrey Watson says:

    I just found one today, South Queensferry (Edinburgh), Scotland UK.

  26. Shawna says:

    Just saw one of these on our giant maple in Massachusetts. Thanks so much for this website! Glad to know that they won’t harm the kids or animals in our neighborhood. Should we be concerned for the trees?

    • bugman says:

      If the Wood Wasp is interested in your tree, the health of the tree is most likely already compromised. Since you saw it on a maple, it is most likely a Pigeon Horntail because the hosts are deciduous trees while other Wood Wasps go for conifers.

  27. Beth says:

    Found one today in Western Pennsylvania

  28. s rennison says:

    One of these very large creatures landed in our back garden today on a conifer tree it was huge and sounded like a helicopter it was without doubt the Giant Wood Wasp in England

  29. Nick McLeish says:

    Where about in England do you live?

    Seen them in the west of Ireland. 40 miles above Galway.

    • andy says:

      I saw one today, it landed on a wooden gate I was about to hang, stoke on trent, Staffordshire, gotta be honest, I nearly shit a brick

  30. Lenny says:

    Just saw one of these scary wasps struggling in the deer netting of our backyard garden (Potomac, Marlyland, USA) – It freed itself and flew away…

  31. Bonnie says:

    Just seen one for the first time this morning while on a walk in my neighborhood . Gross 🙂
    Casper Wyoming

  32. Allen says:

    I saw one of these at work and took some good photos of it. I work at a pulp mill in Prince George BC. Canada
    It is intimidating looking for sure. I have seen a couple over the past few years and have always wondered what it is. The yellow spots on its head must be false eyes for defense. I though they were his eyes until I looked at my pictures. Very cool looking to say the least. I am glad they are harmless. I can’t imagine one landing on you and having to do the scary bug dance.

    • Kyla says:

      Allen, we are also in PG and just found one of these for the first time. Scared the beejezers out of us! My kids were both horrified and fascinated and we spent nearly 2 hours trying to find out what this awful thing was! Crazy nature.

  33. Chris M says:

    They have been in Anchorage, Alaska, for years, we thought they were called a royal Coachman. One stung a weiner dog in the side, dog died that night.

  34. Doug D. says:

    I live west of Chicago about 30 miles and one of these just landed on my screen door. It has a massive stinger (goldish brown) and was about 1.5 inches long from nose to end of stinger. My wife sent it to heaven.

  35. Ruth Anderson says:

    Just found one, fortunately dead, on our garage floor here in Anchorage. Not sure I have ever seen one before but apparently they are not uncommon. Has two fairly wide yellow stripes on black body, two long black thin stinger like things off the back as well as a somewhat shorter one, yet still impressive, that’s yellow. Body & head are 1.25 inches, with stinger it is at least 1.5 inches long. Very interesting looking and glad it was not alive! Must be drilling into our spruce trees – ugh!

    • Chris m says:

      Great you indeed found one dead!!! While weed sacking this summer here in Anch. , one became slightly enraged so I sprayed with Electromotive, about same size as your garage resident. When they are even older, the body bands become blue n yellow, take care!

  36. Mike.R says:

    Just found one in santa cruz, ca never seen one i hope they aren’t moving in were already having trouble with pine beetles and light brown applemoths we don’t need any more pests damaging or forests

  37. J R , Cork says:

    I spotted one in drimoleague in West Cork ,Ireland. It flew into the back of my truck and I couldn’t do any work until I found out what it was and if it was safe. I was petrified.

  38. Susan Keen says:

    I spotted one in our garden in Prince George BC Canada – couldn’t believe the size of it – so beautiful, and the golden coloured wings were amazing. What a lucky day for me!

  39. Paul Rowan says:

    Just spent the day in abergele Wales..
    Felt a slight prick on my calf when walking through the woods.
    Thought it was a piece of Holly or nettle and without much notice pulled one of these off my leg..
    I only looked when I could hear and feel it vibrating between my fingers..
    It was massive and was the longer body and wider stripes that I recognise now..
    Glad to say I resisted the urge to stamp on it when it was on the floor..

  40. Ihavenoidea says:

    Found 1 of this bug yesterday and 1 today never seen before but does it belong in Norway?

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