I try to follow the principle that people should update their beliefs to reflect new information as it comes along, and admit when they were wrong when called for. In that spirit, I would like to retract one of the (many) critical things I have written about Green Party presidential candidate Jill Stein.
I admit it. I was too harsh on her stance regarding honeybees.
Last month, I wrote an article titled "Jill Stein's Ideas Are Terrible. She Is Not the Savior the Left Is Waiting For." Among other issues, it noted that Stein and her party seemed to have an unfortunate tolerance for scientific quackery, such as fearmongering over vaccines and genetically modified foods. That fundamental fact hasn't changed. However, the following line in my piece has not aged well:
She would also “Ban neonicotinoids and other pesticides that threaten the survival of bees, butterflies, and other pollinators.” This is a nod to the discredited theory that some pesticides are driving the collapse of honeybee populations (which, by the way, are not actually collapsing).
I spoke too soon. A major new study published this week in Nature Communications suggests that neonicotinoids, or neonic pesticides, may be responsible for the long-term decline in England's wild bee population. Including Stein's concerns about pollinators on her anti-science rap sheet, it seems, was excessive.
Why did I write that the bee theory was “discredited” in the first place? The controversy involves several distinct but interrelated scientific issues. But when I read Stein's platform plank about pesticides and pollinators, I took it primarily as a reference to the hysteria over colony collapse disorder, “the phenomenon that occurs when the majority of worker bees in a colony disappear and leave behind a queen,” as the Environmental Protection Agency puts it. (Yes, her platform plank mentions butterflies too, but they haven't been the focus of a recent media freak out.) Commercial beekeepers started reporting incidents of collapse in 2006, and the story eventually reached an apocalyptic pitch around 2013. Magazines asked readers to imagine a world without bees. They churned out portmanteaus to describe an impending “beepocalypse” and “beemageddon” that could wreck American agriculture (something has to pollinate all those almonds in California, after all). The timing was a bit ironic; just as U.S. journalists had started whipping up a frenzy over the issue, the percentage of hive losses due to colony collapse disorder each year was actually in decline. But beekeepers have continued to watch a very large fraction of their colonies die annually, and nobody has figured out precisely why. The running theory is that it's probably a combination of factors including parasites like the varroa mite, disease, poor nutrition, habitat destruction and, yes, the multitude of pesticides, herbicides, and fungicides bees encounter in the field.
Many environmental groups, though, have tried to pin blame specifically on neonics, which American farmers began using in the 1990s. The evidence has never been especially strong (though that didn't stop Europe from passing a temporary ban on their use out of an abundance of caution). While scientists agree that neonics can be lethal for bees in large enough doses—they are pesticides, after all—it's not clear the quantities they encounter in the field have much effect. After reviewing the experimental literature and circumstantial evidence, a trio of the field's leading experts concluded in 2012 that, “dietary neonicotinoids cannot be implicated in honey bee declines.” Their position, they added, was “provisional because important gaps remain in current knowledge.” But a smoking gun still hasn't really emerged. The authors of one widely touted study in 2014 claimed they had demonstrated that “neonicotinoids are highly likely to be responsible for triggering 'colony collapse disorder' in honeybee hives that were healthy prior to the arrival of winter.” But the paper was written off by experts who noted that its authors had exposed the poor insects to unrealistically massive doses of pesticides that manufacturers already acknowledged were deadly.
It's also important to understand that despite the large die-offs that have become a yearly event, the U.S. commercial honeybee population actually rose after 2006, thanks to beekeepers who've become adept at rebuilding their colonies. In 2014, it reached a 20-year peak.
So I went with "discredited." Afterward, I had some testy Twitter conversations about whether that word was too strong—there are studies showing neonics have sublethal effects on honeybees for instance, so it's conceivable that they play some role in the constellation of factors behind colony wipeouts. But I felt comfy with my language.
Thanks to the new research out of England, which was funded by the U.K. government, I feel differently. As Nature notes, the study “is the first to link the controversial insecticides [neonics] to the decline of many bee species in real-world conditions.” The scientists looked at 62 species of wild bees using 18 years of data, and found that populations tended to disappear in areas where oilseed rape had been treated with neonics. Notably, species that foraged on the crops suffered significantly greater declines than those that did not. Overall, they estimated the pesticides cut the number of populations by 7 percent on average, and about 10 percent for foragers that may have been feasting on the pesticides.
“Our results provide the first evidence that sub-lethal impacts of neonicotinoid exposure can be linked to large-scale population extinctions of wild bee species, with these effects being strongest for species that are known to forage on oilseed rape crops,” the authors conclude. Industry representatives have complained that the study is only correlational, but I haven't seen an especially compelling rebuttal yet.
To be clear, this study is not about commercial honeybee populations, which are biologically distinct creatures from the wild bees involved in this research. In fact, they are specifically excluded from the study. The scientists write that their results do “support the findings of previous studies on commercially bred pollinators that have identified the underlying mechanisms affecting mortality.” But field research out of Sweden has previously suggested that neonics may have worse effects on wild than domesticated bees. Either way, the paper notes that its authors have received funding for a separate large-scale study on neonics and honeybees.
More to the point, this makes it pretty clear that the neonic controversy shouldn't be tossed into the quack science bin, especially if one is fretting over wild bee populations, which have tended to receive less focus in the U.S., but could certainly be covered by the language in Stein's platform. It seems I leaned a little bit ahead of my skis on this one.