Apple and cherry production is hampered by a lack of wild bees that are affected by habitat loss, pesticides and a climate crisis.
The lack of bees in agricultural areas is limiting the supply of some food crops, according to a new study from the US, which suggests that declining pollinators may have serious ramifications for global food security.
Wild bee species, such as bumblebees, suffer from a loss of flowering habitat, the use of toxic pesticides and, increasingly, the climate crisis. Meanwhile, beekeepers deal with managed honey bees, but they have still been attacked by disease, raising concerns that three-quarters of the world's food crops that depend on pollinators may be reeling due to a lack of bees
The new research appears to confirm some of these fears.
Of seven crops studied in 13 American states, five showed evidence that the lack of bees is hampering the amount of food that can be grown, including apples, blueberries and cherries. A coalition of scientists from the US, Canada and Sweden surveyed a total of 131 farm fields looking for bee activity and crop abundance.
"Crops that got the most bees had significantly higher production," said Rachael Winfree, an ecologist and pollination expert at Rutgers University, lead author of the paper, published by the Royal Society. "I was surprised, I didn't expect them to be limited to this extent."
The researchers found that wild native bees contributed a surprisingly large portion of the pollination despite operating in intensively farmed areas, largely stripped of the vegetation that supports them. Wild bees are often more effective pollinators than honey bees, but research has shown that several species are in sharp decline. The patched and rusty bumblebee, for example, was the first bee to be included on the U.S. endangered species list in 2017 after suffering an 87% drop in the previous two decades.
Swaths of American agriculture are supported by honey bees, frantically replicating and displaced across the country in hives to meet the growing need for crop pollination.
Almonds, one of two crops not shown to suffer from a lack of bees in the study, are grown primarily in California, where most of the hives in the US are trucked each year for a pollination event. massive almond.
The United States is at the forefront of divergent trends that are being replicated in other parts of the world, as agriculture becomes more intensive to produce higher volumes to feed a growing world population, tactics such as crushing wildflower meadows, spraying large amounts of insecticide and planting monocultures. Individual crop fields are damaging bee populations crucial for crop pollination.
According to the Food and Agriculture Organization of the United Nations, the amount of crop production dependent on insects and other pollinators has increased by 300% in the last 50 years. Poor pollination could cause certain fruits and vegetables to become rarer and more expensive, triggering nutritional deficits in diets. However, staples such as rice, wheat and corn will not be affected as they pollinate through the wind.
"Honey bee colonies are weaker than they used to be and wild bees are declining, probably by a lot," Winfree said. “Agriculture is becoming more intensive and there are fewer bees, so at some point pollination will be limited. Even if bees were healthy, it is risky to depend so much on a single species of bee. It is predictable that the parasites will target the only species we have in these monocultural fields ”.
The document recommends that farmers better understand the optimal amount of pollination necessary to increase crop yields, as well as review whether the level of pesticides and fertilizers applied to the fields is appropriate.
"The trends that we are seeing now are setting us up for food safety issues," Winfree said. “We are not yet in a complete crisis, but the trends are not going in the right direction. Our study shows that this is not a problem 10 or 20 years from now, it is happening now.