This may be a bit of a "bee-t up" by the media, the actual figures and their interpretation is disputed, but there is a serious depletion of honey bees in north america. It's thought to be at least partly because of a mite that affects the bees, coupled with the practice of the bee industry in north america of no longer using local bees but shipping bees all over the country to pollinate their little hearts out (literally!) - they may be overstressed by this process and it affects their immunity. At least that's one theory. It almost certainly has nothing to do with mobile phone towers, that just smacks of silly conspiracy theory.