Stump Stabber

Subject: What is it
Location: Minnesota
July 4, 2014 11:50 am
We saw this bug on our dying oak tree. He and his friends remind me of a scorpion but we live in Minnesota.
Signature: P.Pratt

Stump Stabber
Stump Stabber

Dear P.Pratt,
This is a magnificent image of a female
Megarhyssa atrata, commonly called a Stump Stabber.  The female Stump Stabber uses her lengthy ovipositor to place her eggs deep beneath the surface of dead and dying trees that are infested with the larvae of Pigeon Horntails and other Wood Wasps.  The larvae of the Stump Stabbers hatch and feed upon the larvae of the Wood Wasps.  They are considered parasitoids that parasitize and eventually kill the host insect.

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