Bombylius
Bombylius is a large genus of flies belonging to the family Bombyliidae. They are known as the bee-flies, due to their striking resemblance to bees and bumblebees, and are distributed worldwide. One species of the genus, "Bombylius major", is widely distributed throughout the northern hemisphere and is very well known. Physiology. All species in the genus share a similarity with the unrelated bees and bumblebees, which they mimic, possessing a thick coat of fur, with a colour ranging from yellow to orange. They can, however, be told apart from their models by the long and stiff proboscis they  possess, used to probe for nectar as they fly (much like a hummingbird), by their rapid and darting flight, and by the peculiar structure of their legs. As larvae, they are parasitic and infest the nests of solitary bees (and possibly wasps), consuming their food stores and grubs.