New Species - Tree Wasp (Dolichovespula sylvestris)

I'm sure this has wasp has been around but as this is the first time I have formally identified it it must count as a new species and is the fourth wasp to go on the wasp's list. The other two social wasps I have identified are the Common Wasp and the German Wasp. The nest was at ground level hidden (until I accidentally uncovered it) amongst some brambles and thistles.