I haven't seen this hoverfly around since April/May so I was pleased to see a number of them at Trench Wood, Worcestershire. Their numbers peak twice in late May / June and late August / September. This is a small but distinctive species of Hoverfly. In flight the Orange abdomen is very apparent but it's most distinctive feature is it's extended snout.
The series of photos below clearly show the snout from different angles and demonstrate its purpose which is to store and protect it's large proboscis. The proboscis is larger than most hoverflies which is where it gets it's nickname the Heineken Fly. (it reaches the parts other Hoverflies can't reach!)
It should also be pointed out that there is another Rhingia hoverfly called Rhingia rostrata which is very similar to campestris but less common. It has a slightly shorter snout but in the field and without a comparison available that is not too helpful. However the best way to distinguish them is that camestris has a black line along the side of the abdomen which rostrata lacks. You have to see it from the side like in the two photos above.