Pesticides & the silencing of the bees
This month marks the 50th anniversary of Rachel Carson’s Silent Spring, the book that galvanized an extraordinary cross-section of the American public into what we now call the environmental movement. Fifty years later, her courage, skill and sacrifice still inspire, and her legacy remains the contested terrain of some of our country’s most disabling rituals of political partisanship. Pesticides still function as a kind of litmus test: either you’re for farmers and progress and “sound science,” or you’re in the camp of those reflexively “chemophobic” tree-hugging “environmentalists.” And your loyalties to one or the other of these tribes can be indexed to how you feel about pesticides.
Take bees. They have been dying off at about 30% per year since the mysterious “Colony Collapse Disorder” (CCD) was first diagnosed in the U.S. in 2005/2006. If Rachel Carson were alive today she might be writing about the silencing of the bees: honey bees and other wild pollinators (including bats and birds and bumblebees) are seeing catastrophic population declines. These losses are part and parcel of complex global problems like biodiversity collapse and climate change – they are also linked to something much more specific and discrete that we fail to name at our peril. Pesticides.
But what is interesting about the pollinator decline issue is how close to home it hits for so many. People all along the social and political spectrum are freaked out by the sudden decline of bee populations. Even those who don’t know that bees are indicator species still know, on a visceral level, that bees are canaries in the coal mine. Their declining populations signal that something is profoundly wrong – that our environment is unwell and out of balance.
In public discussions of CCD, people generally fall into two camps: those who believe pathogens and parasites are behind bee die-offs, and those who believe that pesticides are the problem.
The truth is that pathogens, parasites and pesticides are all at play. But the fuller truth is that pesticides are absolutely driving bee losses in a number of different ways:
- Herbicides: Increased herbicide use (driven by RoundUp Ready GE crops) is killing off habitat that bees rely on for nutrition.
Older pesticides: Foliar (spray) applications of any number of pesticides while bees are foraging, is still common practice. Bees are especially vulnerable to many insecticides: when you spray when and where they are eating, they die. EPA and the pesticide industry have recently, repeatedly proven that they are unwilling to do anything about this other than tell beekeepers to get out of the way. But thankfully, commercial beekeepers have flatly refused, noting that even if they vacate their hives in time, there is no way to move wild pollinators.
Fungicides: A new class of fungicides – once rarely used on corn – have been widely promoted since 2006 as yield boosters. The few studies we have about the effects of fungicides on bees points to their synergistic effects when combined with neonics (as they often are): they increase the bee-toxicity of the latter up to 1,000-fold. The chemistry of yet another new class of fungicides indicates that they have insecticidal effects. Emerging science also points to fungicides as killing off important bee “gut” microbiota – such as the LB that bees rely upon to turn pollen into bee bread, or the friendly bacteria that combat infection.
“Inert” ingredients: New science out of the University of Pennsylvania’s bee team shows that adjuvants, or “inert” ingredients that make up the bulk of a pesticide product formulation are impacting bee health as well.
- Neonicotinoids: A relatively new class of systemic insecticides (neonicotinoids) covers at least 142 million acres of countryside, much of it corn – on which bees rely heavily for protein. As systemics, these insecticides are water soluable, coursing through plants’ vascular systems to be expressed in pollen, nectar and guttation droplets. This class also happens to be very long-lasting, so they are accumulating in the soil and showing up in the nectar of non-treated plants like dandelions. The most widely used of these neonicotinoids (imidacloprid, clothianidin, thiamethoxam) are known to be highly acutely toxic to bees, and have a variety of sub-lethal effects ranging from disorientation to memory, immunity and reproductive impairment. These pesticides are clearly harming bees – but so do a lot of other pesticides. What makes these neonicotinoids suspect is that they are known to be highly toxic to bees, pervasive, long-lasting and relatively new. Perhaps coincidentally, the emergence of CCD in the U.S. roughly coincides with the 5-fold increase in neonics as seed treatments.
So is it the neonicotinoids killing off our pollinators?
No, not alone. They likely tag-team with other pesticides. They also make bees more vulnerable to the common gut virus, Nosema. New parasites and other pathogens also play a significant role, as do habitat loss and poor nutrition. But we cannot solve this problem without addressing pesticides, they sit at the center of CCD and bee kills alike. And as if helping our farmers transition off the pesticide treadmill were not a sufficiently complex task, it seems that we cannot address pesticides without having the public conversation kidnapped by political partisanship.
Bees are an indicator species. They signal the well being of our broader environment, so their message is important. It is also one that I believe we are capable of receiving.
Our generation, and our children’s generation face overwhelming environmental issues. How do we process climate change? Water and food shortages? Biodiversity collapse? But I think of saving the bees as one of those graspable, manageable things that we can accomplish — and that when we do accomplish it, the effects will ripple and magnify. If we stop poisoning bees, they will thrive and the world we live in will be more resilient as a result.
Originally posted on Stonyfield's blog, The Buzz.