LONDON — From coffee to cocoa, and almonds to blueberries, some of the world’s most nutritionally and economically vital food crops are vulnerable to declines caused by catastrophic die-offs of the bees whose pollination is key to their life cycle.

A multitude of factors, most of them linked to the practices of intensive, industrial-scale agriculture, have been driving down populations of both wild species and commercially bred honeybees around the world.

American beekeepers lost more than 40 percent of their honeybee colonies last year, the White House says. In the Netherlands, wild bee populations have shrunk 90 percent since record-keeping began about 120 years ago, said David Kleijn, an ecology professor at Wageningen University. Some Chinese farmers have to pollinate apple trees by hand because so few bees remain.

“The bees are just not as healthy as they used to be, so they just don’t do the job,” said Tim Tucker, president of the American Beekeeping Federation. Losses this year in his own hives, at Tuckerbee’s Honey in Kansas, are approaching 40 percent.