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Ichneum Wasp, But Which? - Megarhyssa atrata - female

Ichneum Wasp, But Which? - Megarhyssa atrata - Female
Atchison, Atchison County, Kansas, USA
August 5, 2009
Size: 1 1/2" -ovipositor 5"
A very large female... almost 2 inches in length. When we came across her she had this 'odd' blue flat 'bubble' coming from her rear area. The ovipositor, when fully stretched was a good 5inches, was wrapped around it forming the circle.
Anyone know what this was coming out of her...which Ichneumon she is...VERY striking lady!

Moved from Giant Ichneumons.

Moved from ID Request.

possibly Megarhyssa atrata - Giant Ichneumon
This looks pretty similar. Wait for an expert to be sure. I don't know what the blue bubble was. Interesting.

Incredible insects aren't the
Incredible insects aren't they?!?

dup comment

Yes, female, Megarhyssa atrata
Our understanding from earlier comments on this genus, which you can find in the guide by searching on Megarhyssa, is that the bladder-like structure helps in some way in the process of drilling the long ovipositor through the wood to reach the the Horntail larva she is seeking. Tension, Pressure, something.

Intersegmental membrane.
The intersegmental membrane is incredibly elastic in ichneumons, allowing the abdomen to "break" at the junction and generate enough force to drill without the whole apparatus flying apart.

Would you believe, my 10 yo s
Would you believe, my 10 yo son ID'd this for me? He's a book called MiniMonsters that specializes in nature's tiniest monsters (their words...not mine)and he remembered the art work of one of these.
Great info about the ovipositor. And REALLY intimidating to know? The tips are covered in manganese and zinc! Talk about heavy-duty!

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