A lack of bees in agricultural areas in the United States limits the growth of certain crops, according to a new American study. The research suggests that the decline of pollinators could have severe consequences for global food security.
Species of wild bees, such as bumblebees, suffer from the loss of flowering habitats, the use of pesticides, and increasingly, the climate crisis. Of the seven crops studied, five showed evidence that a lack of bees hinders crop growth. Scientists from the US, Canada, and Sweden examined a total of 131 fields for bee activity and crop abundance.
“The crops that received more bees had significantly higher crop production,” says Rachael Winfree, an ecologist at Rutgers University and a senior author of the report, published by the Royal Society. ‘I was surprised; I did not expect growth to be limited to such an extent,’ she said to the British newspaper The Guardian.
The researchers discovered that wild native bees accounted for a surprisingly large share of pollination efforts, despite being largely deprived of supporting vegetation. Wild bees are often more effective pollinators than honeybees, but studies have shown that various species are in sharp decline. The rusty patched bumblebee was the first bee in the US to be placed on the endangered species list three years ago, following an 87% decline in the past two decades.
The United States leads in some agricultural activities where trends are later replicated elsewhere in the world, such as intensification, spraying large amounts of insecticides, and planting monoculture fields with single crops. This is partly seen as a cause of the disappearance of 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. Pollination shortages can cause certain vegetables and fruits to become rarer and more expensive, leading to nutritional deficits. However, staple foods like rice, wheat, and maize are unaffected because they are pollinated by wind.
“Honeybee colonies are weaker than before, and wild bees are probably declining,” says the FAO. “Agriculture is becoming more intensive and there are fewer bees, so at some point pollination will become limited. Even if honeybees were healthy, relying so much on a single bee species is risky. It is predictable that parasites will target the one species we have in these monocultural fields.”