Apparently California is having a lot of problems with this according to a recent program I heard. In some cases, some bee keepers have lost over half their hives. Doesn't bode well for the California fruit industry at all.

Most farmers rely on and pay bee keepers to move hives onto their farms, particularly for such things as almonds, berries and tree fruits, to ensure a crop. When the bees have done their job, after the plants finish flowering, they are moved on to other crops.

This has become a primary business for beekeepers, over collecting honey, in some areas. There are no longer enough wild bees or good bee habitat, to just rely entirely upon nature for pollination, without a considerable helping hand.