What's That Bug? does not endorse extermination

large wasp-type bug with long ‘tail’
November 17, 2009
This bug came in when we opened our back door one evening a few nights ago. Sorry, my husband squished it. The envelope it’s sitting on is a business-sized (10 inch) envelope for size reference. It’s very dark or black with a long jointed looking body, black wings and the really long tail that totally creeps me out. 🙂
Scaredy Cat
North Texas/DFW

Squashed Giant Ichneumon

Squashed Giant Ichneumon

Dear Scaredy Cat,
This is a female Giant Ichneumon, Megarhyssa atrata, and she is perfectly harmless.  The tail, though it looks like a stinger, is actually an ovipositor.  With her long ovipositor, the female Giant Ichneumon drills into diseased wood to lay an egg on the larva of a wood boring insect, the Pigeon Horntail.

after reading your site for over an hour the night that I posted, I learned the purpose of that long tail thingy. Wish we wouldn’t have squished her. It was fear-induced carnage. 😉 With 3 cats and 2 children she probably wouldn’t have lasted long anyway!
Thanks for responding and confirming what I found on your site. We also have great photos of a wooly caterpiller that looks like what the Japanese Monster Mothra was based upon. 🙂 Can we just submit photos even when we know what the bug is?

Hi Kim,
You may submit photos, but please use our question form and provide your location.  Also, please do not submit more than one species of insect per letter.  We are very happy to hear you were able to make your identification without our assistance.

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What's That Bug? does not endorse extermination

24 Responses to Squashed Giant Ichneumon

  1. We were walking home from my neighbors house when suddenly a huge wasp-looking insect flew right in front of my face! It really reminded me of a stingray because of the long tail. It landed on the tree near by, so I went to look at it. But when I walked away it6 came after me like it was going to sting me!!! I think that I saw a Giant Ichneumon. I had never seen a bug like that before. I live in South Dakota.

  2. margo says:

    I seen one of those bugs on neighbors window in Valparaiso , In

  3. Dan says:

    I saw about ten of these on a dead elm tree. They looked like they were having some very deep sex with the tree. I tokd my neighbor he was going to have a nightmare about one with a fifteen foot ovipositor breaking his window and going through his ear, waking to a slight headache, then one day his head would explode with the brain consuming larvae. Sorry-my brain hurts somehow. Thanks for the id… Oh, this is Minnesota-twin cities.

  4. Hannah says:

    Today at 8:56 there was one in my house on my ceiling. First time I’ve ever seen one. I thought it was a wasp with human hair hanging from the back when I realized it was attached. Caught it, and threw it outside. Very VERY glad to know it is harmless.
    Oklahoma OK

  5. Amber says:

    I just saw this bug. I too was scared! Good to know they are harmless. South East South Dakota

  6. Josh says:

    A coworker brought a half dead one to me in a box never seen it before in my life glad i found this article now i know

  7. Walter White says:

    Had one flying around the front porch tonight. What a cool looking bug! I wouldn’t describe it as wasp like, though. It resembles a May Fly, but in black with a long tail. I suspected the “tail” may be some reproductive structure, and it is! Very impressive lol

  8. Husband just seen one of the Ichneumons in his pole barn, left it alone, still there.

  9. Craig says:

    Just seen one now here in central Massachusetts June 2017

  10. V Wood says:

    Southern Illinois 8-8-17. I have lived in the country most of my 60 years and saw this bug today for the first time ever. Glad to come by your site here. She was on the outside of the screen but scary enough I might have killed her inside. Now I know not to. 🙂

  11. summer says:

    today I found one in my pool when i was cleaning lets just say i was not so happy to see it . i did not want to kill it so i want on google and typed in black bug with long tail thing . thank you now i know its not so bad so i set it free i am so glad to have found this website .

  12. Margaret says:

    We live in Southern Indiana. My sons bedroom has an exit door to the back yard which was open & one of these flew into his room while he was on his computer. Yes, he killed it then yelled for me to come see something. OMG it was big with this very long like tentacle hanging out of the rear of his body. He didn’t know they were harmless or he wouldn’t have killed it. First time any of us in the house saw something like that. It sure was scary looking.

  13. LanitaSunshine says:

    I just saw one at work in Columbia SC. She’s still alive and kicking.

  14. Laura Guindon says:

    I think that I discovered a new species. Thoughts..

  15. Jackie says:

    Saw one tonight for the first time.. freaked me out!! Southaven MS

  16. Seth says:

    I’ve never seen one before. Glad I had the opportunity

  17. Tyrone says:

    We saw one at work yesterday flying around the warehouse. Nobody knew what it was. Now I know its harmless. Knoxville Tn.

  18. Jan says:

    We have a similar bug but it gets in behind our vinyl siding so we think it is building a nest. It always goes in the same vinyl siding in a corner and it has a very long thin thing attached to it rear. It does not bother us as we are about 3 feet from the vinyl where it enters. We are sitting on our deck and watch it go into the vinyl. Where it goes after it is under the vinyl we don’t know and we are very concern. What should we do kill it??

    our deck. should we be Leary that it might not be one of these bugs you all are talking about. we are in ohio

  19. angie says:

    Just seen one of these in my lobby, scared me to death. Had to google this one. Illinois.

  20. Danny Cassell says:

    just had one of these land on the hood of a van i’m working on in Nova Scotia Canada

  21. Laurie says:

    Just saw one on our pickle vines here in south central Wisconsin right on Illinois border

  22. Almo says:

    Just saw one here in Riyadh Saudi Arabia

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