A lack of bees in agricultural areas limits the supply of some food crops, a new US-based study has found, suggesting that the decline in pollinators could have serious consequences for global food security.
Wild bee species, like bumblebees, are suffering from loss of flowering habitat, the use of toxic pesticides and, increasingly, the climate crisis. Managed honey bees, on the other hand, are maintained by beekeepers, but have historically been plagued by disease, raising fears that three-quarters of the world’s pollinator-dependent food crops are weakening due to a lack of bees. .
The new research seems to confirm some of these fears.
Of seven studied crops grown in 13 states in America, five showed that a lack of bees hampers the amount of food that can be grown, including apples, blueberries and cherries. A total of 131 crop fields were studied for bee activity and crop abundance by a coalition of scientists from the United States, Canada and Sweden.
“The crops that had more bees had significantly higher production,” said Rachael Winfree, ecologist and pollination specialist at Rutgers University, lead author of the article published by the Royal Society. “I was surprised, I didn’t expect them to be so limited.”
The researchers found that wild native bees contribute a surprisingly large amount of pollination, despite operating in intensively cultivated areas largely devoid of the vegetation that supports them. Wild bees are often more efficient pollinators than honey bees, but research has shown that several species are in sharp decline. The rust-spotted bumblebee, for example, was the first bee to be listed as endangered in the United States in 2017 after suffering an 87% decline in the previous two decades.
Sections of American agriculture are supported by bees, replicated frantically and moved across the country in beehives in order to meet a growing need for crop pollination.
Almonds, one of two crops that did not suffer from a bee shortage in the study, are primarily grown in California, where most beehives in the United States are trucked annually for massive pollination. almonds.
The United States is at the forefront of divergent trends that are reproducing elsewhere in the world – as agriculture becomes more intensive to produce greater volumes to feed a growing global population, tactics such as flattening meadows of wildflowers, spraying large amounts of insecticide and planting monoculture fields of single crops damage bee populations crucial for crop pollination.
According to the Food and Agriculture Organization of the United Nations, the amount of agricultural production dependent on insects and other pollinators has increased by 300% over the past 50 years. Pollination deficits could make some fruits and vegetables rarer and more expensive, causing nutritional deficiencies in diets. Staple foods such as rice, wheat and corn will not be affected, however, as they are pollinated by the wind.
“Honey bee colonies are weaker than they used to be and wild bees are in decline, probably by a lot,” Winfree said. “Agriculture is more and more intensive and there are fewer bees, so at some point pollination will become limited. Even if the bees were healthy, relying so much on just one bee species is risky. It is predictable that the pests will target the only species we have in these monoculture fields.
The paper recommends that farmers better understand the optimal amount of pollination needed to increase crop yields, as well as check whether the level of pesticide and fertilizer applied to fields is appropriate.
“The trends we are seeing right now are preparing us for food security challenges,” Winfree said. “We are not yet in a complete crisis now but the trends are not going in the right direction. Our study shows that this is not a problem in 10 or 20 years – it is happening now. ”