Green Shield Bug
The name shield bug is due to the shield shape of the adult insects when seen from above.
Often mistaken for beetles, shield bugs belong to a different group of insects, the Hemiptera. They feed by sucking sap from a wide range of plants but generally cause no noticeable damage to cultivated plants, even when numerous.
In the last few years I've been noticing more and more of these little bugs, and it seems to have become more abundant and widespread in the UK as a whole. This one landed on the outside table and seemed happy to sit on my finger and swop stares.... ain't it cute.. ;O)