Volucella bombylans
Various hover flies imitate bumble bees, but you have to becareful: most bee flies also look like bumble bees. The bee flies are even bigger than the hover flies, extremely hairy and they have a very long snout. Because of this snout they often hover in front of flowers, taking the nectar the same way a humming-bird would. Hover flies always sit down on a flower before taking the nectar out of it. Some hover flies imitate bumble bees so well, you might have a problem telling them apart. The hover flies however are better flyers than the bumble bees are, they have much shorter antennae end bigger fly like eyes. Volucella bombylans below imitates bumble bees. It is a big hover fly reaching a length of some 2 centimeters. The species is extremely variable, as it imitates various bumble bees. The one in the top picture obviously wants to look like the Earth Bumble Bee (Bombus terrestris), while the one below it imitates the Red-tailed Bumble Bee. It is very hard to imagine they belong to one and the same species! In such cases it is a good habit to use the longer scientific names. Starting of with the name of the genus, starting with a capital (in this cae Volucella), followed by the name of the species (in this case bombylans) followed by the name of the form or subspecies. The imitator of the Red-tailed Bumble Bee is scientifically known as Volucella bombylans bombylans. The subspecies mimicing the Eart (or Garden) Bumble Bee is called Volucella bombylans plumata. The larvae of this hover fly lives in the nests of bumble bees, eating the rubbish the bees produce and possibly the bees larvae as well. You'll find a good comparison between the Bumble Bee and its imitator in the two bottom pictures.
