So I was mowing the lawn, when I suddenly saw something oddly large moving, I stopped and got of the lawn mower, only to find a rather large bumblebee(?) being chased by a wasp. I disturbed them and squashed the wasp and found that the bumblebee(?) had climbed on top of one of the wheels of my lawn mower. So I took some pictures of it. I then held my phone next to it and it climbed on top of it. With the bumblebee(?) on my phone, I moved it to some flowers, which it instantly climbed into. Could anyone tell me what this insect is? Is it really a bumblebee or is it something else? It also appeared to be losing its lower body, it wasn't moving much.

Any info to satisfy my curiosity is appreciated