Study – Common Chemicals Harm Honey Bees’ Health

by Sabrina I. Pacifici on August 11, 2013

“Commercial honey bees used to pollinate crops are exposed to a wide variety of agricultural chemicals, including common fungicides which impair the bees’ ability to fight off a potentially lethal parasite, according to a new study by researchers at the University of Maryland and the U.S. Department of Agriculture. The study, published July 24 in the online journal PLOS ONE, is the first analysis of real-world conditions encountered by honey bees as their hives pollinate a wide range of crops, from apples to watermelons. The researchers collected pollen from honey bee hives in fields from Delaware to Maine. They analyzed the samples to find out which flowering plants were the bees’ main pollen sources and what agricultural chemicals were commingled with the pollen. The researchers fed the pesticide-laden pollen samples to healthy bees, which were then tested for their ability to resist infection with Nosema ceranae – a parasite of adult honey bees that has been linked to a lethal phenomenon known as colony collapse disorder. On average, the pollen samples contained 9 different agricultural chemicals, including fungicides, insecticides, herbicides and miticides. Sublethal levels of multiple agricultural chemicals were present in every sample, with one sample containing 21 different pesticides. Pesticides found most frequently in the bees’ pollen were the fungicide chlorothalonil, used on apples and other crops, and the insecticide fluvalinate, used by beekeepers to control Varroa mites, common honey bee pests.”

  • See also: “..a study by the European Food Safety Authority (EFSA) has labeled the pesticide clothianidin as being an “unacceptable” danger to bees. At least 143 million of the 442 million acres–that is, nearly one-third–of US cropland is planted with crops treated with one of three neuroactive insecticides related to nicotine (a newer class of pesticide called neonicotinoids), all of which are known to be highly toxic to bees: clothianidin, imidacloprid, and/or thiamethoxam. Clothianidin, which is used to treat up to 90% of US corn, much of canola, and increasingly soy as well, expresses itself through the plants’ pollen and nectar–the honeybee’s favorite sources of food. In addition to finding clothianidin too dangerous to use on plants pollinated by bees, EFSA’s study specifically identifies the shoddy studies provided by pesticide manufacturer Bayer as evidence of clothianidin’s safety as “too flawed to be useful.” It was these studies that EPA used to first approve clothianidin in 2003, even against the objections of EPA’s own scientists.”

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