Great photo of a REALLY TINY insect! This, however, is a fly, not a bee. It has bee-like markings as a defense mechanism: most birds, toads, etc. know NOT to attempt to eat a bee! This is called a Hover Fly, for the unique way they can hover in one spot. You can tell flies from bees this way: flies have VERY tiny antennae and HUGE eyes placed close together. I've learned that the majority of fly species are actually beneficial, as they focus on pollinating MANY flowers, just like this Hover fly is.
Marcia