The Marmalade Hoverfly (Episyrphus balteatus) is Britain’s most common hoverfly. Its larvae feed on aphids.
The patterning on the abdomen is very distinctive making this species easy to identify. However the orange colour can be bright or much darker – depending on the temperature in which the larvae were living. Orange hoverflies emanate from larvae in warm conditions and darker individuals from ones living in cooler environments.
A Dartmoor blog 