An Asian virus has also been implicated. I think it's more than one factor, including stress on the bees. I think they are quitting their jobs (migrant workers) and have found a quiet field somewhere in Canada...
A local beekeeper who has been in the honey business since the '30s lost nearly all his colonies last fall/this spring. He doesn't move them, but they are being encroached on by development and they have to travel farther to find food as all the farming is now gone.
Vikki 1969 Goldenrod Yellow / black 400 convertible numbers matching