I found this deceased female Tremex after looking closely at a tree that was split in half by a storm. - Tremex columba

3rd picture

I was referring to the black slightly curved thing which is attached to the insect at one end, to the tree at the other.
The ovipositor is the short brown thing sticking out of the bottom of the insect :) correct?

… Lruso, 24 July, 2013 - 10:05pm

See Dr. Carlson's comment below.

The slender structure penetrating the wood is the ovipositor; the stouter structure sticking out the back is its sheath.

… Ken Wolgemuth, 24 July, 2013 - 10:19pm

High Res Photo

Here is a high resolution image that shows the ovipositor and sheath alongside each other (from 2006 paper by Schiff et al.)

… Bob Carlson, 25 July, 2013 - 6:28am

Wow, very impressive, thank y

Wow, very impressive, thank you.

… Lruso, 25 July, 2013 - 10:31am

Moved

Moved from ID Request.

Nice shots of oviposition, and the structure of the ovipositor itself.

… Ken Wolgemuth, 24 July, 2013 - 6:46pm

Thank you sir, I am proud of

Thank you sir, I am proud of them.

… Lruso, 25 July, 2013 - 10:28am

Mr. Carlson what is the black

Mr. Carlson what is the black thing in its abdomen and attached to the tree?
Isnt the ovipositor the brown thing ?

… Lruso, 24 July, 2013 - 3:04pm

Ovipositor

I assume you are referring to the spine-like structure protruding from the abdomen. It is the ovipositor--the structure that the female uses to inject her eggs into the host tree. In hornets and other aculeate Hymenoptera, it no longer serves this purpose but has instead evolved into a stinger.

… Bob Carlson, 24 July, 2013 - 4:00pm

I think the contributor is referring...

...to the slender structure most clearly visible in the third shot, which appears to descend from the abdomen into the wood almost vertically. Is that the actual ovipositor? And is the stout, backward-pointing structure the sheath in which it normally resides?

… Ken Wolgemuth, 24 July, 2013 - 6:26pm

Yes

The ovipositor and the sheaths are as you identify them.

… Bob Carlson, 24 July, 2013 - 6:34pm

Pigeon Tremex

Not hornet.

… Bob Carlson, 24 July, 2013 - 2:43pm