In mid-June, some 50,000 bees were found dead in a suburban shopping-center parking lot in Wilsonville, Ore. — the largest mass bumblebee die-off ever recorded. The culprit: a pesticide called Safari that was sprayed onto the blooming linden trees that line the parking lot to control aphids, which secrete a sticky residue that can be a nuisance when it falls on cars. Safari's primary ingredient is dinetofuran, a compound that belongs to a class of pesticides known as neonicotinoids, which appear to contribute to the ongoing decline of North American and European bee populations.
In response to the Wilsonville bee die-off — and another a few days later in Hillsboro, a nearby suburb, involving hundreds of bees and the same pesticide — the Oregon Department of Agriculture issued a 180-day moratorium on dinetofuran products used for plant pest control. Federal legislation introduced in July, the Protecting America's Pollinators Act (H.R. 2692), would go further by effectively banning neonicotinoid use until research has determined that these pesticides are not harmful to bees. This restriction would be similar to the two-year ban the European Union issued in April for three widely used neonicotinoids.
A month after the dead bees were discovered in Wilsonville, 37 million bees were found dead in Ontario. One local beekeeper, who said he lost 600 hives, blamed the heavy use of neonicotinoids on nearby cornfields. Over the past 10 years or so, bee populations have been declining dramatically, with commercial beekeepers experiencing annual hive losses of 30 to 50 percent and sometimes more. Given that the majority of the world's 100 most important food crops, or one in every three bites of food worldwide, depend on insect pollination, the ongoing and steep decline in bees is of great concern. While neonicotinoids are not considered the sole contributor to bee populations' collapse — diseases and parasites are also factors — many scientists think the pesticides contribute to losses by impairing bees' ability to feed and by weakening their immune systems.
Introduced in the 1990s and welcomed as safer alternatives to previous pesticide classes, a number of neonicotinoids were rapidly approved by the U.S. Environmental Protection Agency (EPA). They are now the world's most widely used pesticides. There are dozens of neonicotinoid pesticide products, including home-garden products, manufactured and sold by numerous companies. Neonicotinoids are used on approximately 75 percent of all acres planted with food crops in the United States, on 95 percent of all U.S. corn and widely on landscaping plants.
Considered less toxic to mammals (including humans) than some other types of widely used pesticides, neonicotinoids work by attacking insects' nervous systems. They also differ from many other pesticides in that they are often used as systemic pesticides, applied to seeds or directly into tree trunks and then staying with the plant as it grows, including when it blooms. That means the pesticides are present in the pollen and nectar on which bees and other pollinators feed. Several recent studies by scientists at Purdue University, the Connecticut Agricultural Experiment Station and the University of Stirling in Scotland, among others, have found neonicotinoids in pollen at levels that can harm bees after the pesticides were used as directed by manufacturers. There is concern that exposure is also harmful to birds that feed on treated plants.
The problem, according to Scott Black, executive director of the Xerces Society, a nonprofit dedicated to invertebrate conservation, is that, used as directed — at levels that kill target pests — the neonicotinoids are harming bees. "This is what happened in Hillsboro," said Black. "The pesticide was used as directed." But CropLife America, a trade association representing pesticide manufacturers, says that "when used properly and according to the label, there has been no demonstrated extraordinary negative effect on bee health associated with the use of neonicotinoid-based pesticides."
According to a report just released by Friends of the Earth and the Pesticide Research Institute, the majority of plants purchased at U.S. home-garden centers contained neonicotinoids. The plants chosen for testing were those described as bee-friendly because of their blooms known to attract bees. On Aug. 14, authors of the report sent a petition with more than 175,000 signatures to retailers asking them to stop selling neonicotinoids and plants treated with these pesticides.
On Aug. 15, the EPA announced new neonicotinoid labeling requirements, which the agency believes will help curtail their use in places where bees are present. The new labels, due to appear on products in 2014, will have a bee advisory box and icon and information about exposure routes and other precautions. This is just one part of the agency's efforts to address pollinator health, an EPA spokesperson explained via email. It is in the process of reviewing several neonicotinoid registrations, a process scheduled to be completed in 2018, and says that it "will take appropriate regulatory action," depending on the outcome of those studies.
Pesticide Action Network North America spokesman Paul Towers said the new labels "would do little to address the problem of bee declines" and called on the EPA to "act on the growing body of scientific evidence and further restrict use of neonicotinoids." He said "there is no way to effectively mitigate a pesticide which is systemic and persistent in a plant," even with additional labeling guidelines. The labels will do little to help native bees, Black said. "Most independent scientists think we've already reached a point of urgency. The last decade of data points to that."
"The trajectory for damage to pollinator populations, particularly honeybees, has been really troubling," said Rep. Earl Blumenauer, D-Ore., a lead sponsor of H.R. 2692, in a phone interview. Despite public concern about bees, he said he was not optimistic about the prospects for the pollinator-protection bill's passage. He did, however, see "a real opportunity" that pollinator protection would be included in the Farm Bill, the large agricultural-policy bill passed every five years that Congress is expected to take up again when it convenes after Labor Day. An amendment addressing pollinator protection was attached to the House bill in June and passed with bipartisan support. A similar amendment was introduced in the Senate but was not voted on before it passed its version of the bill.
In March, four beekeepers and five environmental and consumer groups filed suit against the EPA, claiming that it ignored scientific information about neonicotinoids' toxicity to bees when it approved the category of pesticides, including neonicotinoid products approved through an expedited process called "conditional registration." In July, another suit was filed against the EPA over its approval of a new insect neurotoxicant pesticide without evidence that it won't harm bees. The beekeepers and environmental advocates contend that the EPA has not paid sufficient attention to the pesticides' potential adverse long-term or sublethal effects on bees or to the chemicals' effects on bees in combination with other stressors, such as disease, parasites, and habitat loss.
Meanwhile, the EPA has issued new guidelines for investigating bee kills and is working with beekeepers, pesticide manufacturers and applicators, seed companies and farmers to better protect pollinators. But environmental advocates do not want to keep neonicotinoids on the market while further research is conducted and want their use halted.
"We need to be concerned about short-term activities, but it is the long term we're concerned with," said Blumenauer. The pollinator-protection bill, he said, is but "a very limited response to a potentially very big problem."