Cute idea! :-)
I like the texture of the wings. I would suggest to give the brown strips a stronger curvature. Like now they really flatten the bumblebee, which would be much cuter in it's naturally round shape.
I really like this composition, and your characters are really fun. I think this is a really fun piece in the making! The horse/donkey's back leg seemed a little off to me though, so I sketched in what seems to me a bit better. Its a hard angle and I'm no expert, so feel free to take this or leave it. :-)