As reported by Der Spiegel,
As far back as 2005, Haefeker ended an article he contributed to the journal Der Kritischer Agrarbericht
(Critical Agricultural Report) with an Albert Einstein quote: "If the bee disappeared off the surface of the globe then man would only have four years of life left. No more bees, no more pollination, no more plants, no more animals, no more man."
Interestingly, I've been saying for the last 5 years or so that of all the extinctions happening, the one I've been most worried about is the honey bee.
You can read the article at www.spiegel.de