As far as i know, no, humanity won't disappear when bees would do (even though I have seen people claiming it). Sure, some plants might solely depend on bees for pollination, but there are also plants which don't and there are also other pollinators. See https://skeptics.stackexchange.com/questions/30495/do-bees-p... for example:

    The authors of the FAO analysis concluded that the proportion of global food production
    attributable to animal pollination ranges from 5% in industrialized nations to 8% in the developing world.

That being said: it is pretty hard to predict waht would happen suppose there were no bees at all. I doubt it would be nice though.