She is using her ovipositor to insert eggs into tree-apparently there are beetle larvae that bore into wood, she then lays her eggs in the larvae-her eggs hatch and eat the beetle larvae. Freaky stuff.-I am not a professional, though I think I have given you correct info.

They are parasitoids of Horntail larvae, family Siricidae. So because of that they are beneficial insects. They are not harmful at all and really are more afraid of us than anything. Watch one if you ever find it again, they beat their antennae on the wood looking for the larvae, and they are very slow at inserting and extracting the ovipositor. Unless they're startled, then they go a little faster :) You'd have to sit there and watch it insert its ovipositor into you for it to sting you, which they wouldn't even try anyway. Everytime I've suprised one it just flys away.

Thank you so much. That is the most interesting thing I've ever heard. Are they dangerous at all? Can they sting?

Here is an article that addresses your genus and the possibility of stinging-they can drill wood, but apparently probably don't normally sting people- http://skagit.wsu.edu/MG/bugs/Ichneumon%20Wasps.pdf

Thank you so much.

More info here: http://bugguide.net/node/view/4158

Perhaps someone else here can determine species.

Thank you so much.