This is one of the largest Hoverflies that we have. Its name is Volucella zonaria and it belongs to the family of insects known as Syrphidae. Like all true flies, Diptera, it only has one pair of wings, Bees and Wasps have two. Although they mimic Bees or Wasps they don't sting and are completely harmless, in fact they are the gardeners friend as their larvae eat pest species.
The eyes are huge, but as you can see on this picture they are composed of thousands of small lenses (compound eyes). Unlike bees or wasps they have very small antennae. This one was very dozy and let me take a few photos before it suddenly woke up, started buzzing and flew off. As it name suggests it has a characteristic way of flying, hovering in one place before darting off to a new point.
In May and June I catch Cockchafers, but I was surprised when I started catching them again in July. But they're not, these are Summer Chafers.