Declining Bee Populations Are Threatening Crop Yields

This tomato plant needs this bee!  (Photo: Patrick Pleul, Getty Images)
This tomato plant needs this bee! (Photo: Patrick Pleul, Getty Images)

Bees are on the decline. New research suggests that could have serious implications for global access to food.

Most of the world’s crops, including a third of the food humans eat every day, relies on pollination, mainly by bees. But due to habitat degradation, viruses, the widespread use of toxic pesticides, and climate breakdown, bees are dying globally at an alarming rate.

A new study, published in the Royal Society’s journal Biological Sciences on Tuesday, examined the impact of reduced bee populations on crop yields. The authors analysed data from more than 130 farms in U.S. and Canada that grow apples, blueberries, sweet cherries, tart cherries, almonds, pumpkins and watermelon.

They found that five of the seven crops showed evidence of lowered yields due to less pollination by smaller bee populations. Early spring crops, including apples, cherries, and blueberries, were hit hardest by this decreased pollination. Only pumpkins and watermelons — both late summer crops — fared ok, possibly because they grow in warmer and sunnier weather that’s more hospitable to bees. They also don’t have to compete with as many seasonal flowers for bees’ attention, which may improve success rates for pollination.

Much of the U.S. and Canada’s agriculture is supported by domesticated honeybees, which aren’t native to the region. But the researchers were surprised to find that native, wild bees played an equally important role, even though the farmland they examined had been largely stripped of the native plants on which those bee species rely.

“Even in these major production regions, for most crops, wild bees were doing similar amounts of crop pollination as that done by the honey bee,” Rachael Winfree, an ecologist at Rutgers University who was a senior author of the study, told Earther in an email.

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Since the research suggests intensively farmed land can still support native bee populations and domesticated ones, the authors call for policymakers and farmers to protect both.

To do so, the authors suggest we take steps to make farmland more hospitable to them. That includes putting more honeybee hives in crop fields, as well as increasing the number of wildflowers on agricultural land to attract and support more native bees. Farmers can also use fertilisers and pesticides with bees in mind, too

“An important step is to minimise the use of pesticides that are highly toxic to bees, particularly neonicotinoids,” said Winfree. “Growers can also leave areas of semi-natural habitat on their farm, such as borders of crop fields, where bees can nest and forage on flowers.”

Since bees are also threatened by the climate crisis, we can also help them by drawing down carbon emissions to protect them from even more inhospitable conditions. Just a thought.

These methods all make good economic sense. In the U.S., the authors estimate that the annual production value of honeybees to agriculture is $US6.4 ($9) billion, and peg the value of wild bees at over $US1.5 ($2) billion. Plus, better pollinated crops tend to be juicier and tastier.

But more importantly, preserving bees is necessary to preserving food security. The production of crops which are dependent on pollinators, like fruits and vegetables, has increased by 300% in the last 50 years. If crop yields plummet due to lowered bee populations, food could become more expensive and therefore less accessible to many people around the world.