Photograph of a Drone-fly, Eristalis tenax, of the hoverfly family Syrphidae, on a marigold (Image source: Wikipedia). The larvae of the Drone-fly can be found in foul, stagnant pools and drains, in sewage, and in streams and ponds. The adults feed on pollen and nectar, particularly from yellow flowers of the Compositae.
Honeybee mimicry in Drone-flies deters some predators, in particular toads (Brower and Brower, 1965), but birds may not be deceived so readily.
Brower, J.Z. and Brower, L.P. (1965) Experimental studies of mimicry. VIII. Further investigations on honeybees (Apis mellifera) and their dronefly mimics (Eristalis spp.). American Naturalist 99, 173-187.
Gilbert, F.S. (1986) Naturalists’ Handbooks 5: Hoverflies. Richmond Publishing Co., Slough, UK.