Volucella bombylans is a large species of hoverfly

Hoverfly

Hoverflies, sometimes called flower flies or syrphid flies, make up the insect family Syrphidae. As their common name suggests, they are often seen hovering or nectaring at flowers; the adults of many species feed mainly on nectar and pollen, while the larvae eat a wide range of foods...

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It is larger than most hoverflies at 20mm long, and looks something like a Bumble bee with a furry black, yellow and/or white body, but is given away by its head and eyes which show it is a true fly, like a Blow-fly

Blow-fly

Calliphoridae are insects in the Order Diptera, family Calliphoridae...

. It occurs in several forms each of which mimics a species of Bumble bee. It can be found even in urban gardens, sunning itself on a leaf. It is a fast flier.