The flower petals are blown out, and the focus seems to be on the green behind it, which distracts from your subject. I would like to see the flower a little more from the front, and the flower center in focus with the bees in motion. A polarizer might help if you're not already using one.
Nicely done but the colours seem a little blown out. Maybe using a higher number on the Aperture will allow the movement blur but controlling the light some more.
I think the big bee is going to lay the smack down on the little bee. I like this because it would be a super tough capture. I am not totally sold on the crop of the flower, but I understand you were trying to preserve the size of the bee.
The image doesn't convey motion blur to me. I know you want us to look at the flying bee but from what I can tell it was just out of focus. The composition itself is good and the focus on the closer bee is good, but I just don't see it meeting the challenge.
Unfortunately, I'm not sure this type of picture is going to work. It comes across as just a blurred bee, as opposed to the motion blur conveying something.