That's interesting, I have read that Mason Bees are not plant specific and are actually extremely important pollinators (especially for Apple trees). Anyway, with the imports gone there are definately a lot less pollinators out there now.
All the better reason to encourage the natives to roost in your gardens, etc. Hopefully, there were(are) some resistant honeybees out there and next year a resistant population will bounce back to replace the delpleted population of honeybees.
I won't get into a rant about antibiotics and pesticides but... I will. My hope is that North American governments won't go on an Antibiotic/peticide rampage trying to eliminate this virus. For one thing, Viruses are none living and therefore antibiotics are of little or no use. Secondly, such substances will only cause more damage than harm (I won't go into specifics). The best bet is to have some resistance in the populations of the bees and the only hope for that is that the bees have not been totally inbred.
I'll keep my fingers crossed.