Stump Stabber sighted in Michigan

Subject:  What is this flying insect? It was about 3” long with approx a 3” stinger (?) attached.
Geographic location of the bug:  Near Battle Creek, MI
Date: 08/20/2022
Time: 04:00 PM EDT
Your letter to the bugman:  Appreciate you identifying this insect for us. We have never seen one of these before and have live here for over 60 years!
How you want your letter signed:  Dave Hlatko

Stump Stabber

Dear Dave,
Thanks for your inquiry.  This is one of Daniel’s favorite insects to educate about,
Megarhyssa atrataa species commonly called the Giant Ichneumon or Stump Stabber.  Daniel distinctly remembers as a child seeing an impressive image of a Giant Ichneumon in his copy of Insects: A Guide to Familiar American Insects.  Your individual is a female and what you have mistaken for a stinger is her ovipositor, an organ that allows her to deposit her eggs.  In the case of the Giant Ichneumon, the ovipositor is able to drill into dead and dying wood to lay an egg near the tunnel produced by the larva of the Pigeon Horntail, a type of Wood Wasp.  Because of her ability to oviposit, the Giant Ichneumon is sometimes called a Stump Stabber.  The stingers of bees and wasps are modified ovipositors that have evolved into an organ that helps to defend the insect from threats.  

2 thoughts on “Stump Stabber sighted in Michigan”

  1. Dear What’s That Bug

    I am happy to tell some good news.
    I am an older person and have a caregiver. We live in the country, on the Banks of the Tumbling Parus.
    Insects are part of everyday life.

    We have some good bugs. My caregiver used to be afraid of them. She still has arachnophobia. But now she has started taking pictures of them, so she can hear my stories.

    She wants to know if they are dangerous and what do they eat.

    This is great! Just a year ago, if she saw a big bug,she would have killed it and went to the fainting couch.

    This year, she took pictures of our local Dynastes, and something she called an ant beetle. A colorful little fellow.

    This is so wonderful to see.


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