'I'm doing a small science project on the Drone-fly,' the student explains, 'and my understanding is that they use mimicry. They look like a small bee, and so I was wondering what they use this for. What animals are they protected from by using mimicry?'
I'm usually wary of completing someone-else's project, but this question intrigues me. Here's the answer I sent;
The usual suggestion, of course, is that for a harmless animal to mimic one that can protect itself (in this case with a sting) gives it some protection. The story is that a bird that has been stung by a Honey Bee will, to be on the safe side, avoid drone-flies. It sounds fair enough to me, but as this is a science project you shouldn't just accept it at face value. Scientists are incredibly sceptical.
I expect you've got to ask yourself;
PredatorsI don't recall having seen a drone-fly being attacked by an insect but, no doubt, dragonflies would target them. If a drone-fly gets caught in a spider's web the mimicry would be of limited use because web-spinning spiders don't rely primarily on eyesight. I've seen spiders deal with bees, carefully dabbing them with their spinnerets until they have their prey bundled up in silk.
The most spectacular bird I've seen going for bees was in Greece where a flock of Bee-eaters were circling above a hill village. We could hear the 'snap' of their beaks as they caught bees (or wasps perhaps). Bee-eaters are blue and yellow, reddish brown, green, black and white. They're probably the most colourful birds that you can see in Europe.