Uncoperative Bee - (with weird thing on back!)

Tried my hardest today to get a nice side or frontal bee shot and there was only one main bush attracting them so spent 15 minutes or so at various angles trying to get one. Got loads of rear action but none with both flower and bee in complete focus.
Still I managed to select the very first image of a lovely looking one burrowing into the flower as my favourite but have put a couple of the fails into my blipfolio here as they were almost there where I wanted but the bees have a mind of their own and were not in a posing mood today :-)
Just had a closer look and not sure if that is some sort of bee tick between its wings so went back to the original picture a did a tighter crop but still not sure!!? Freaky thing!