After some research I discovered it is called an assassin bug from south/central america. It obviously hitched a ride on the plant and was surviving on it. So what to do with a non native and somewhat interesting looking bug.
My youngest has a fascination with insects and her favorite activity in the summer is to capture and examine whatever she can get her hands on and successfully into a container without killing it to examine it more closely. So into a container to examine more closely it is.
So far I've learnt that it is a very aptly named insect, I wouldn't have wanted to be the little spider that found it's way into this bugs new home anyways.
