Imidacloprid, a widely used neonicotinoid pesticide, is a potential threat to honeybee hives as well as individual bees when used on crops that attract pollinators, the EPA said in a preliminary risk assessment. Residues that exceed 25 parts per billion trigger effects that include deaths of bees and lower honey production. The report “could lend impetus to efforts to ban the chemical,” said the Los Angeles Times. “Honeybees are used to pollinate crucial food crops and contribute about $14 billion in value to the agricultural economy nationwide.”
A Canadian assessment reached the same conclusion about the impact on hives. Canada’s Pest Management Regulatory Agency said “a potential risk to bees was indicated for bee-attractive crops associated with pre-bloom, during-bloom and some post-bloom applications” when the pesticide was sprayed onto plants. There was some risk from soil application of imidacloprid but no risk when used as a seed coating.
Jim Jones, the EPA’s assistant administrator for chemical safety, said the agency’s preliminary assessment “is a pretty big step forward in increasing our understanding of the potential for imidacloprids to impact colony health,” reported the Guardian. Three neonicotinoids, including imidacloprid, are currently banned in the EU.
Meanwhile, beekeepers and environmental groups announced a lawsuit against EPA for allowing “millions of pounds” of seeds coated with neonicotinoids “to be planted annually on more than 150 million acres nationwide” without adequate regulation or study of the impact. “Up to 95 percent of the applied seed coating ends up in the surrounding air, soil and water rather than in the crop for which it was intended, leading to extensive contamination,” said the Center for Food Safety, one of the plaintiffs.
The so-called neonics, used on grain, fruit, vegetable, oilseed and legume crops, have been blamed for high mortality rates among commercial honeybee hives. Parasites such as the Varroa mite, poor nutrition, and adverse weather also have been blamed. Bees and other pollinators play a significant role in U.S. food production.
Last year, the EPA proposed a ban on the use of neonicotinoids when crops are in bloom and bees are under contract for pollination services. It also halted temporary approval of new uses of neonics until pollinator risk assessments are complete. The EPA said it planned to release preliminary pollinator risk assessments for three other neonics — clothianidin, thiamethoxam, and dinotefuran — in December, as well as a preliminary risk assessment of imidacloprid on all types of plants and animals.
The agency said its data on imidacloprid “show that citrus and cotton may have residues of the pesticide in pollen and nectar above the [25 ppb] threshold level. Other crops, such as corn and leafy vegetables, either do not produce nectar or have residues below the EPA identified level. Additional data is being generated on these and other crops to help the EPA evaluate whether imidacloprid poses a risk to hives.”
A 60-day comment period will begin when the pollinator-risk report is published in the Federal Register.