A few interesting facts from this article:
‘Independence’ almonds still performed better when bees were assisting in pollination. They had a 60 percent increase in fruit set and a 20 percent increase in kernel yield when pollinated by bees. Even with the cost of renting colonies, farmers would still realize 10 percent more profit when the almonds were fertilized by bees.
Eighty percent of the world’s almonds are produced in California. The crop requires the pollination services of two million colonies of honey bees during the flowering season, which growers rent from beekeepers. Pollinating almonds requires the equivalent of moving half of all managed bees in the U.S. to California for a few weeks.