I have seen many of those bumble bee-like flies in Eastern Canada. In a few cases I mistakenly followed one believing it was a Bombus impatiens worker. These flies belong to the Syrphidae, which include some of the most striking bee mimics. The Genus Mallota and Voluvella have fine yellow hairs on the thorax and the basal portion of the abdomen that resembles the pile of a bee, the remaining hairs are black or entirely lacking. The fly closely resembles a bumble bee worker. Mallota sp. and Voluvella sp. are easily distinguished from a bee, because they have large compound eyes which meet dorsally, short club-like antennae and lack of a pollen carrying basket. Bee flies (Family: Bombylidae) are easily distinguished from Syrphids by a long proboscis which may be as long as the body. Best Wishes, Blair Blair Sampson Dept. of Entomology Auburn University Alabama 36849-5413 [log in to unmask]