Giant Ichneumon

Subject: Strange wasp? Cape Cod
Location: Cape Cod, MA
July 21, 2014 5:56 am
My niece was in Cape Cod last year and couldn’t identify what this (wasp?) is. I’ve never seen anything like it. She asked several scientists that were there too and they couldn’t either. I don’t know if any were entomologists. It was just hanging out on a picnic table I believe.
Signature: Joe

Stump Stabber
Stump Stabber

Hi Joe,
We sincerely doubt that any of the scientists were entomologists, because even those that specialize in other insect orders should recognize a Giant Ichneumon or Stump Stabber in the genus
Megarhyssa.  Despite the formidable looking ovipositor, Giant Ichneumons are not aggressive and they are not capable of stinging humans.  With that stated, the ovipositor is used by the female to lay eggs beneath the surface of dead and dying trees and stumps that contain the wood boring larvae of Horntails and Woodwasps, so it might be possible for the ovipositor to pierce human skin, though we think it is highly unlikely for a Stump Stabber to mistake a human limb for an infested tree.  Several members of the genus look very similar, so we are reluctant to attempt a species identification.  Another distinctive member of the genus, Megarhyssa atrata, is our featured Bug of the Month for July 2014.

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