[kragen]

Around here the passion flowers are mostly pollinated by a species of bumblebee with an almost-all-black abdomen and beautiful violet wings. So far they haven't stung me, although I'm sure they could, and it would be very painful. I haven't tried capturing them.

[chihuahua]

It sounds like it could be Xylocopa violacea, the violet carpenter bee, found in Europe and Asia: https://en.wikipedia.org/wiki/Xylocopa_violacea

[kragen]

I'm in South America, and it doesn't look very similar: http://canonical.org/~kragen/bumblebee.jpeg

I think these are also much larger than the violet carpenter bee.