Drone Fly

Eristalis tenax is the most cosmopolitan species of hoverfly (family Syrphidae) and one of the most-cited examples of Batesian mimicry in insects. Adults are nearly indistinguishable from European honey bees (Apis mellifera) in coloration, body proportions, buzz frequency, hovering flight pattern, and flower-visiting behavior. The mimicry deceives most predators (insectivorous birds, dragonflies, mantises) and routinely fools human beekeepers and casual observers. The fly has no sting and is completely harmless. The aquatic larva is the famous 'rat-tailed maggot' — a fat cylindrical maggot that lives in the most foul, low-oxygen, putrid water imaginable (sewage lagoons, manure runoff, stagnant puddles, decaying carcass body cavities), breathing through a remarkable telescoping siphon at the rear that extends up to 5x the body length to reach the water surface for atmospheric air. The larval ecology is the basis for the species' biblical fame: scholars generally interpret the 'bees in the carcass of a lion' story in Judges 14:8 (Samson and the riddle) as drone flies misidentified as bees — the rat-tailed maggots breed readily in putrid carrion, and the emerging adults swarm out as 'bees.' E. tenax is one of the most ecologically valuable pollinators outside the bees themselves; she is increasingly studied as a potential managed pollinator alternative for the global decline of honey bees.