The world honey bee population has plunged in recent years, worrying
beekeepers and farmers who know how critical bee pollination is for many
crops. A number of theories have popped up as to why the North American
honey bee population has declined–electromagnetic radiation,
malnutrition, and climate change have all been pinpointed. Now a leaked
EPA document reveals that the agency allowed the widespread use of a
bee-toxic pesticide, despite warnings from EPA scientists.

The
document, which was leaked to a Colorado beekeeper, shows that the EPA
has ignored warnings about the use of clothianidin, a pesticide produced
by Bayer that mainly is used to pre-treat corn seeds. The pesticide
scooped up $262 million in sales in 2009 by farmers, who also use the
substance on canola, soy, sugar beets, sunflowers, and wheat, according
to Grist.

The leaked document (PDF)
was put out in response to Bayer’s request to approve use of the
pesticide on
cotton and mustard. The document invalidates a prior Bayer study that
justified the registration of clothianidin on the basis of its safety to
honeybees:

Clothianidin’s major risk concern is to
nontarget insects (that is, honey bees). Clothianidin is a neonicotinoid
insecticide that is both persistent and systemic. Acute toxicity
studies to honey bees show that clothianidin is highly toxic on both a
contact and an oral basis. Although EFED does not conduct RQ based risk
assessments on non-target insects, information from standard tests and
field studies, as well as incident reports involving other
neonicotinoids insecticides (e.g., imidacloprid) suggest the potential
for long-term toxic risk to honey bees and other beneficial insects.

The
entire 101-page memo is damning (and worth a read). But the opinion of
EPA scientists apparently isn’t enough for the agency, which is allowing
clothianidin to keep its registration.

Suspicions about
clothianidin aren’t new; the EPA’s Environmental Fate and Effects
Division (EFAD) first expressed concern when the pesticide was
introduced, in 2003, about the “possibility of toxic exposure to
nontarget pollinators [e.g.,
honeybees] through the translocation of clothianidin residues that
result from seed treatment.” Clothianidin was still allowed on the
market while Bayer worked on a botched toxicity study [PDF], in which test and control fields were planted as close as 968 feet apart.

Clothianidin
has already been banned by Germany, France, Italy, and Slovenia for its
toxic effects. So why won’t the EPA follow? The answer probably has
something to do with the American affinity for corn products. But
without honey bees, our entire food supply is in trouble.

Related:

Beekeeper Who Leaked EPA Documents: “I Don’t Think We Can Survive This Winter”

Timeline of a Bee Massacre: EPA Still Allowing Hive-Killing Pesticide

Ariel Schwartz can be reached on Twitter or by email.