"I hope it doesn't sting!"

I spotted this interesting critter on the kitchen window a couple of weeks ago.  Here it is:

I hadn't seen this insect before and it got my attention - the body and "tail" are around 10cm long.  Some searching revealed it is a giant ichneumon wasp, introduced here in the sixties to help control another wasp, Sirex noctilio, that is a pest in forests. 

That long "tail" is an ovipostitor to lay eggs in the grubs of its host species deep in trees and dead logs. 

There is a good discussion here: http://bugeric.blogspot.co.nz/2009/06/giant-ichneumon-wasps.html

Halfway down the comments,  Fallon says this: "I just smashed one of these evil-looking bastards with a hammer. It did not look harmless and was sure that "tail" was some kind of needle. And I live on the south island of New Zealand! Invasive? Thanks for the info. Will not kill the next one I see."

They certainly look a touch menacing but no need to smash them!