What's tipping honeybee populations into huge annual die-offs? For years, a growing body of evidence has pointed to a group of insecticides called neonicotinoids, widely used on corn, soy, and other US crops, as a possible cause of what has become known as colony collapse disorder (CCD).
Rather than kill bees directly like, say, Raid kills cockroaches, these pesticides are suspected of having what scientists call "sub-lethal effects"—that is, they make bees more vulnerable to other stressors, like poor nutrition and pathogens. In response to these concerns, the European Union recently suspended most use for two-years; the US Environmental Protection Agency, by contrast, still allows them pending more study.
But according to a new peer-reviewed paper, neonicotinoids aren't the only pesticides that might be undermining bee health. The study, …show more content…
The researchers found insecticides and fungicides in in every hive, and herbicides in nearly a quarter. Putting aside the bees' health for a moment, one way to read the results is as a survey of what farmers are spraying on some of the main fruit and vegetable crops we eat. Looking at it that way, it's alarming that organophospates—an insecticide class known to be a powerful neurotoxin—were found in 63.2 percent of the hives. Another nasty pesticide class, pyrethroids, showed up in every sample.
But it was the fungicides that caused the most concern in the second part of the experiment. The researchers took disease-free bees, divided them into groups, and subjected them to three kinds of diets: two control diets free of insecticides traces, and one featuring samples of pollen collected from each of the field sites. Then they exposed them all to Nosema spores, and examined which bees became infected, and which managed to fight it
Rather than kill bees directly like, say, Raid kills cockroaches, these pesticides are suspected of having what scientists call "sub-lethal effects"—that is, they make bees more vulnerable to other stressors, like poor nutrition and pathogens. In response to these concerns, the European Union recently suspended most use for two-years; the US Environmental Protection Agency, by contrast, still allows them pending more study.
But according to a new peer-reviewed paper, neonicotinoids aren't the only pesticides that might be undermining bee health. The study, …show more content…
The researchers found insecticides and fungicides in in every hive, and herbicides in nearly a quarter. Putting aside the bees' health for a moment, one way to read the results is as a survey of what farmers are spraying on some of the main fruit and vegetable crops we eat. Looking at it that way, it's alarming that organophospates—an insecticide class known to be a powerful neurotoxin—were found in 63.2 percent of the hives. Another nasty pesticide class, pyrethroids, showed up in every sample.
But it was the fungicides that caused the most concern in the second part of the experiment. The researchers took disease-free bees, divided them into groups, and subjected them to three kinds of diets: two control diets free of insecticides traces, and one featuring samples of pollen collected from each of the field sites. Then they exposed them all to Nosema spores, and examined which bees became infected, and which managed to fight it