I have one or two of these guys this year in addition to my regular bumble bees. They are at least twice the size of the BBs and have a different wing shape and marking. They are not very aggressive, I was quite annoying to this one, trying to get decent pictures.
Not a bee, but a robber fly (family Asilidae) known as the Beelzebub bee-eater - http://www.flickr.com/photos/coolmajaka/3310252958/
Thanks, even knowing the name it is hard to find information about him. A blurb and lots of pictures. I really thought they were going for pollen, so now I need to get back out there and watch more closely. Would love them to decimate our wasps and leave the bees alone.
Joy
