A shortage of bees in agricultural areas limits the supply of some agricultural crops, a new study in the United States found that suggests a decline in pollinators could have serious consequences for global food security.
Wild bee species, such as bumble bees, are suffering from the loss of a flowering habitat, the use of toxic pesticides and, increasingly, the climate crisis. Managed bees have meanwhile been working with beekeepers, but are still affected by disease, leading to fears that three-quarters of the world̵7;s food crops dependent on pollinators could weaken due to a shortage of bees.
New research seems to confirm some of these concerns.
Of the seven crops studied in 13 states in the United States, five showed that bee deficiencies hampered the amount of food that could be grown, including apples, blueberries, and cherries. A coalition of scientists from the United States, Canada and Sweden surveyed a total of 131 crop fields in terms of bee activity and crop abundance.
“Crops that have gained more bees have received significantly more crop production,” said Rachael Winfree, an ecologist and pollination specialist at Rutgers University, who was the lead author of an article published by the Royal Society. “I was surprised, I didn’t expect them to be limited to this range.”
The researchers found that wild bees contributed a surprisingly large proportion of pollination, despite operating in intensively farmed areas that were largely inhabited by vegetation that supports them. Wild bees are often more effective pollinators than honey bees, but research has shown that some species are declining sharply. For example, the rusty bumblebee was the first bee to be listed as an endangered species in the United States in 2017 after an 87% decline in the previous two decades.
Honey bees are grown alongside American agriculture, feverishly reproduced and moved throughout the country in hives to meet the growing need for crop pollination.
Almonds, one of two crops that were not shown to be deficient in bees in this study, are grown mostly in California, where most beehives in the United States are loaded each year for a massive almond pollination event.
The US is at the forefront of divergent trends that are replicating anywhere in the world – as agriculture intensifies to extract larger quantities to feed a growing global population, tactics such as leveling wild meadows, spraying large amounts of insecticides and growing monoculture plants. The fields of individual crops damage the bee populations that are 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% over the last 50 years. Deficiencies in pollination could cause certain fruits and vegetables to become rarer and more expensive, leading to a lack of nutrition in the diet. However, basic foods such as rice, wheat and maize will not be affected because they are pollinated by the wind.
“Bee colonies are weaker than before and wild bees are declining, probably by a lot,” Winfree said. “Agriculture is more intensive and there are fewer bees, so pollination will be limited at some point. Even if bees were healthy, it is risky to rely on a single species of bee. It is predictable that the parasites will target one species that we have in these monocultural crop fields. “
The document recommends that farmers better understand the optimal amount of pollination needed to increase yields, as well as verify that the level of pesticides and fertilizers in the fields is adequate.
“The trends we are seeing now are preparing us for food security issues,” Winfree said. “We are not in a complete crisis yet, but trends are not moving in the right direction. Our study shows that this is not a problem in 10 or 20 years – it is happening right now. “