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Bees pollinate the flowers that become fruits, nuts and vegetables. The work these busier insects do is worth about $18 billion a year to U.S. agriculture.
But honeybee colonies in the United States have been shrinking by about a third each year for the past several years.
Colorado beekeeper Tom Theobald says the worst of the die-offs usually happen in the winter.
“If you were a rancher, you’d go out there and you’d have a dead cow. In the case of the bees, there may or may not be a carcass. They may have mostly disappeared with just a small remnant [of the hive] left.”
This mysterious disappearance has been termed colony collapse disorder. Colony collapses account for about a third of the overall loss of honeybees each year, according to the U.S. Department of Agriculture.
No one knows exactly why it happens. But one suspect is a class of pesticides called neonicotinoids. First introduced in the 1990s they are now commonly used to coat the seeds of many major crops around the world. The seedlings absorb the chemical as they grow. So, rather than needing to indiscriminately spray a whole field, there is a little bit of insecticide inside each plant.
But that includes the plant's pollen and nectar that the bees are after. It is not enough to kill them. But it may be harming them nonetheless. According to new research in a journal "Science".
Lead author Mickaël Henry from the French national agriculture research institute, INRA, explains at the press conference in Paris: “Individuals explores to very small doses of those pesticides ??? of their daily activity. Well, those bees actually had probability to dissapear away ??? much greater proportions".
Henry and his colleagues glued tiny microchips on bees backs. The chips tracked the insects as they came and went from their hive.
The researchers fed the bees sugar water spiked with a low dose of a neonicotinoid and sent them out to forage. They found these bees were about twice as likely to fail to return as bees not exposed to the insecticide.
Henry says the bees basically get drunk.
“Intoxicated honeybees with those small doses may just get lost and are unable to find their way back home"
And it’s not just honeybees that are affected.
Dave Goulson heads research on wild bomblebees at Britain’s University of Sterling. He and his colleguaous published an accompanying study in this journal.
“There were 85 percent fewer queens produced when they’d been exposed to realistic field levels of neonicotinoids, which clearly could have very significant implications for bumblebee populations in the wild.”
??? only bumblebee queens survive the winter to start new colonies each spring.
That could help explain why bumblebee populations are declining along with the domesticated honeybees. And around the world, wild pollinators like bumblebees are more important than honeybees for certain crops.
Bayer CropScience, which makes neonicotinoid pesticides, disputes the findings.
Jack Boyne is a spokesman:
“Instead of dosing the animals at field-relevant concentrations as the authors intended, they instead dosed them at levels that are far greater than what would commonly be experienced in the field." Sixty times greater, Boyne says. At that level, he says, it is not surprising that the bees were disoriented.
And he notes that researchers are studying many other factors affecting bee populations, including parasites, diseases, and the stress of transporting commercial beehives.
But honeybee colonies in the United States have been shrinking by about a third each year for the past several years.
Colorado beekeeper Tom Theobald says the worst of the die-offs usually happen in the winter.
“If you were a rancher, you’d go out there and you’d have a dead cow. In the case of the bees, there may or may not be a carcass. They may have mostly disappeared with just a small remnant [of the hive] left.”
This mysterious disappearance has been termed colony collapse disorder. Colony collapses account for about a third of the overall loss of honeybees each year, according to the U.S. Department of Agriculture.
No one knows exactly why it happens. But one suspect is a class of pesticides called neonicotinoids. First introduced in the 1990s they are now commonly used to coat the seeds of many major crops around the world. The seedlings absorb the chemical as they grow. So, rather than needing to indiscriminately spray a whole field, there is a little bit of insecticide inside each plant.
But that includes the plant's pollen and nectar that the bees are after. It is not enough to kill them. But it may be harming them nonetheless. According to new research in a journal "Science".
Lead author Mickaël Henry from the French national agriculture research institute, INRA, explains at the press conference in Paris: “Individuals explores to very small doses of those pesticides ??? of their daily activity. Well, those bees actually had probability to dissapear away ??? much greater proportions".
Henry and his colleagues glued tiny microchips on bees backs. The chips tracked the insects as they came and went from their hive.
The researchers fed the bees sugar water spiked with a low dose of a neonicotinoid and sent them out to forage. They found these bees were about twice as likely to fail to return as bees not exposed to the insecticide.
Henry says the bees basically get drunk.
“Intoxicated honeybees with those small doses may just get lost and are unable to find their way back home"
And it’s not just honeybees that are affected.
Dave Goulson heads research on wild bomblebees at Britain’s University of Sterling. He and his colleguaous published an accompanying study in this journal.
“There were 85 percent fewer queens produced when they’d been exposed to realistic field levels of neonicotinoids, which clearly could have very significant implications for bumblebee populations in the wild.”
??? only bumblebee queens survive the winter to start new colonies each spring.
That could help explain why bumblebee populations are declining along with the domesticated honeybees. And around the world, wild pollinators like bumblebees are more important than honeybees for certain crops.
Bayer CropScience, which makes neonicotinoid pesticides, disputes the findings.
Jack Boyne is a spokesman:
“Instead of dosing the animals at field-relevant concentrations as the authors intended, they instead dosed them at levels that are far greater than what would commonly be experienced in the field." Sixty times greater, Boyne says. At that level, he says, it is not surprising that the bees were disoriented.
And he notes that researchers are studying many other factors affecting bee populations, including parasites, diseases, and the stress of transporting commercial beehives.
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