Beekeepers have seen average population losses of around 30 percent every year since 2006. (Photo by Enrique Lara.)

Beekeepers have been concerned that pesticides are to blame for the bee die-offs devastating their industry for a while now. As we reported recently, their losses have spiraled out of control, putting not just the beekeepers but our entire agricultural system in peril.

The concern centers around a class of pesticides called neonicotinoids, which the Environmental Protection Agency (EPA) allowed to be marketed and sold even after the agency’s own scientists’ put up red flags. And now some in the industry have decided it’s time to formally challenge EPA’s negligence. On March 21, 27 beekeepers and four environmental groups filed a petition [PDF] with the agency asking it to take clothianidin — the neonicotinoid causing the most trouble — off the market until a long-overdue, scientifically sound review is completed.

The EPA asked Bayer — the manufacturer of clothianidin — to conduct a study looking at its effects on bees and other pollinators back in 2003, but allowed Bayer to sell the pesticide under “conditional registration” in the meantime. Bayer didn’t produce a field study until 2007, and in spring 2010, clothianidin was quietly granted full registration. But later that year a leaked document revealed that EPA scientists had found Bayer’s study inadequate. “By that time, the pesticide was all over the country,” said Peter Jenkins, an attorney with the Center for Food Safety, the lead legal group on the petition. “We felt that what EPA did was illegal.”

The beekeepers’ petition claims EPA violated the Federal Insecticide, Fungicide and Rodenticide Act by not enforcing its requirement for a field study proving clothianidin’s safety, and that this failure creates an imminent hazard to the environment. The petition also holds EPA in violation of the Endangered Species Act for not properly assessing clothianidin’s effects on threatened species.

EPA said it would work with Bayer to design a better study, Jenkins said. But beekeepers don’t have time to wait; they’ve seen average population losses of around 30 percent every year since 2006. “At the rate this agency goes, we know it would be years and years before they actually completed [a new study],” Jenkins said. “So we’re saying, fine, just suspend use of the pesticide until the study’s done.”

It’s unlikely that such a study, if carried out properly, would produce results different from what a wealth of peer-reviewed research has already shown: Clothianidin and other neonicotinoids (or neonics) harm pollinators. A new report from the Xerces Society for Invertebrate Conservation handily summarizes the science so far: Plants grown from seeds treated with nenonics absorb the chemical through their vascular systems, and the residue in their pollen or nectar can be lethal to insects that come to forage. Even exposure to sublethal levels of neonics can affect bees’ immune systems and their ability to fly, navigate, communicate, and learn new tasks –- all crucial to keeping a hive functioning. And pollinators face multiple exposure routes to neonics besides direct contact with treated plants: They can be poisoned by the exhaust spewing from machines used to plant treated seeds, either by flying through it or by foraging in nearby fields where the dust has drifted. Once neonics are present in soil, they can stay there for up to six years, meaning untreated plants sown in subsequent years may still absorb chemical residues.

It’s no wonder, then, that beekeepers in both the U.S. and Europe can trace their problems more or less back to when commercial farmers began transitioning away from integrated pest management — a system in which insecticides are sprayed once a pest problem arises — and toward neonicotinoids, which, as Jenkins explained, “are too good, too efficient; they turn a simple corn plant into a killing machine.”

If EPA doesn’t respond to the petition, Jenkins said the Center for Food Safety and other petitioners could sue the agency. But he’s “reasonably optimistic” that EPA will wise up. “We made a really good case, and it’s helped by this new report [from the Xerces Society],” he said. “It’s not unheard of — EPA has responded in the past when it’s clear that a pesticide is killing something in ways that the agency hadn’t analyzed.”

Last summer, EPA ordered a recall of DuPont’s herbicide Imprelis, which had been linked to tree deaths across the U.S. Imprelis, like clothianidin, had been on the market under conditional registration, though it debuted only a year before its recall. Also like clothianidin, Imprelis’ labeling did not warn about its potential danger to another species — even though, it turns out, DuPont knew before its release that Imprelis could harm trees. The beekeepers’ petition to the EPA calls the labeling of clothianidin “defective.”

Since EPA scientists themselves have acknowledged clothianidin’s harmful effects on bees and proclaimed the Bayer study to be inconclusive, getting the chemical off the market comes down to yet another uphill battle against a government agency in thrall to corporations — in this case, the chemical industry. Maybe this petition — backed by over a million citizen petitions — will give EPA the push it needs to listen to its own experts.

UPDATE: The New York Times reports on two new studies published Thursday in the journal Science that give further evidence for neonicotinoids’ role in bees’ decline.