[Pollinator] Exotic species of bees in North America have produced little detectable disruption of native bee communities

[Peter Loring Borst]

Rangelands Magazine devotes June 2011 special issue to pollinators.

Excerpt:

the 20 plus exotic species of bees in North America have produced
* little detectable disruption of native bee communities *
thus far, certainly not on a par with exotic plants. The
European honeybee's impact on native bees -- mostly through
exploitative competition for pollen and nectar -- remains
debatable and may prove unknowable because they were
introduced four centuries ago, long before anyone studied
our native bees. In my opinion, it is the precise and targeted
elimination of the worst exotic plants -- particularly by well conceived
biological control methods -- that will eventually
benefit native bees the most, if removing the exotic weedy
species helps to heal native plant communities. 

Meeting Wild Bees' Needs on Western US Rangelands
Author(s): James H. Cane
Source: Rangelands, 33(3):27-32. 2011.