Believe the Buzz: New Research Firmly Links Pesticides to Bee Decline

Mortality rates were 10 percent higher for bees exposed to large amounts of one particular neonicotinoid.
(Photo: Frank Bienewald/Getty Images)
Aug 22, 2015· 1 MIN READ
Samantha Cowan is an associate editor for culture.

Environmentalists have long believed that a class of pesticides called neonicotinoids are at least partially responsible for the mass die-offs of honeybees. They are, after all, designed to kill insects. Government agencies requested more research to confirm this widely accepted claim, and now, they’ve got it.

A study published Thursday firmly links one particular neonic, imidacloprid, to the death of bees.

Researchers at the Food and Environment Research Agency in the U.K. studied pesticides as seed treatment on oilseed rape crops across nine different regions in Wales and England. Because the neonic is applied to the seed, the chemical stays in the crop as it grows. The 11-year study found that mortality rates were 10 percent higher for bee colonies that had high levels of exposure to imidacloprid than for those with low field exposure.

Past studies have found that large amounts of neonics resulted in bee deaths, but these reports were met with criticism because they didn’t reflect what bees would encounter in real-life scenarios.

“This is one of the most compelling cases yet for the fact that neonics are harming bees,” Paul Towers, a spokesperson for Pesticide Action Network, wrote in an email to TakePart. “Researchers in this study looked in particular at canola grown in the U.K., but the same lessons can be applied to the millions of acres of corn and soy planted in [the U.S.] that are also coated with this bee-harming pesticide.”

Pesiticides aren’t the only culprit for bee decline. Many point to a formidable mite, Varroa destructor, as the primary cause of bee deaths. The mites can prove especially dangerous to weakened or malnourished bees and certainly contribute to bee deaths, but as Towers notes, mites have been around for a long time.

“No doubt [mites] play a role in overall declines, but the evidence suggests pesticides are the driving factor, and declines are consistent with their wide-scale introduction in the mid-2000s,” he said. Honeybee colony collapse was first observed in 2006, and the bee population has declined by one-third since then.

Bees are vital to the world’s food supply. They’re responsible for one in every three bites of our food and pollinate $15 billion worth of crops each year.

The White House announced plans to protect bees in May, including restoring bee-friendly habitats and refraining from spraying pesticides when honeybee hives are present, but did not ban the use of neonics on the crops that bees pollinate.

Towers hopes this new research will serve as “a wake-up call for the White House to go even further and create more havens for our honeybees.”