The above wasp is a parasitic species; it may be an Ichneumon, but I don’t feel confident identifying them at all, so let’s just stop at the broadest level (“Parasitica,” unofficial group), until someone else brings a more expert opinion to bear.
Regarding parasitoids like this, they often have long “stingers” which in fact are simply ovipositors, i.e. the egg-laying organ. The stinging wasps and bees have ovipositors as well, but theirs have evolved to inject venom for predatory or defensive purposes, as well as laying eggs. I was unable to get a clear confirmation, but I am under the impression that most if not all parasitic wasps are non-stinging.
They are rather interesting animals, and I highly recommend Charley Eisman’s blog, BugTracks, if you’d like to learn more about them (as well as other insects and creatures we’d hardly ever know about). A lot of insects featured on his site are very tiny wasps and flies and moths that emerge from collected galls. (A gall is an abnormal growth or structure on a plant or tree, often caused by a developing insect.) The wasp in my photo is actually quite a bit larger. I think people see these kinds hovering around like little menaces, but they really are harmless. I often find them patrolling my yard, presumably in search of whichever insect serves as their host; they move in floaty fits and starts, stopping here and there to inspect a patch of grass, and do not like to be approached. They are the kind of insect subject that you can follow around for however long you like and never get within five feet of. In this case here, I found a winner.