What would happen to civilization if bees completely died off?

No mass starvation, because the grains that make up the bulk of our diet are not at risk. (Wind-pollinated.) So we’d have corn, bread, oatmeal, etc. And certain fruits, such as grapes, are wind-pollinated or self-fertilizing.

And then there’s human pollination, as they’re doing in China. (Take millions of peasants, hand them bundles of chicken feathers, and let them climb through the fruit trees, touching every flower with a bit of pollen from a bucket.) What we’d have is extraordinarily high prices for most of the fruits and vegetables that provide our vitamins and antioxidants, if they could be found at all. And the beef and dairy industry, as Michael Pollan has pointed out, is switching more and more away from natural forage to corn, even though corn makes cattle sick, because it’s cheaper to feed corn and administer antibiotics to sick cattle than it is to use nature pasture. So we’d still have a beef industry, though a freaky one.

But honeybees aren’t on the edge of going extinct. They are, however, on the edge of not being able to provide all the pollination we’ve asked of them.