Scientists Confirm: Pesticides Kill America’s Honey Bees...
Honey bees are quickly disappearing from
the US – a phenomenon that has left scientists baffled. But new research
shows that bees exposed to common agricultural chemicals while
pollinating US crops are less likely to resist a parasitic infection.
As a result of chemical exposure, honey bees are more likely to succumb to the lethal Nosema ceranae parasite and die from the resulting complications.
Scientists from the University of Maryland and the US Department of Agriculture on Wednesdaypublished a study that linked chemicals, including fungicides, to the mass die-offs.
Scientists have long struggled to find the cause behind the Colony
Collapse Disorder (CCD), in which an estimated 10 million beehives at an
average value of $200 each have been lost since 2006.
Last winter, the honey bee population
declined by 31.1 percent, with some beekeepers reporting losses of 90 to
100 percent of their bee populations. Scientists are concerned that
“Beemageddon” could cause the collapse of the $200 billion agriculture
industry, since more than 100 US crops rely on honey bees to pollinate
them.
The new findings are key in determining
one of the causes of the CCD, but they fail to explain why entire
beehives sometimes die at once.
UMD and DOA researchers found that pollen
samples in fields ranging from Delaware to Maine contained nine
different agricultural chemicals, including fungicides, herbicides,
insecticides and miticides. One particular sample even contained 21
different agricultural chemicals. To test their theory, they fed
pesticide-ridden pollen samples to healthy bees and then infected them
with the parasite. They found that the pesticides hindered the bees’
abilities to resist the infection, thus contributing to their deaths.
The fungicide chlorothalonil was particularly damaging, tripling the
risks of parasitic infection.
“We don’t think of fungicides as having a
negative effect on bees, because they’re not designed to kill
insects,” Dennis vanEngelsdorp, the study’s senior author, said in a
news release.
He explained that federal regulations
restrict the use of insecticides while pollinators are foraging, but
noted that “there are no such restrictions on fungicides, so you’ll
often see fungicide applications going on while bees are foraging on the
crop. The finding suggests that we have to reconsider that policy.”
Bees are declining at such a fast rate
that one bad winter could trigger an agricultural disaster. California’s
almond crop would be hit particularly hard, since the state supplies 80
percent of the world’s almonds. Pollinating California’s 760,000 acres
of almond fields requires 1.5 million out-of-state bee colonies, which
makes up 60 percent of the country’s beehives. The CCD is a major threat
to this $4 billion industry.
Entomologists suspect that a number of
other factors also contribute to the CCD, including climate change,
habitat destructing and handling practices that expose bees to foreign
pathogens. But the effect of agricultural chemicals is particularly
alarming, especially since the US does not have laws banning the use of
the pesticides that are affecting bee health.
“The pesticide issue in itself is much
more complex than we have led to believe,” vanEngelsdorp said. “It’s a
lot more complicated than just one product, which means of course the
solution does not lie in just banning one class of product.”
Thanks
RT News