I have been reading some internet info about honeybee pollination, and in the process discovered some people in the U.S. are using native bees in increase pollination in some crops.  Some questions:

Is use of native bees for pollination common?

Is there concern that beekeepers are affecting the native bee populations negatively by "supporting" non-native honeybee population?

I had thought that the different parasites attacking (non-native) honeybees in the U.S. in the past few decades had decimated our native bee populations also.   The statistics I found in different websites are either vague or don't seem to back this concept.  Can anyone tell me specific info or lead me to links discussing native bee populations?

Thanks!
Inger Lamb
Iowa, USA