New Discovery About What's Killing Honey Bees

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August 19, 2014 • 41,330 views

Story at-a-glance

  • A new study on Colony Collapse Disorder in honeybees offers additional evidence of the impact of neonicotinoid insecticides on this potentially devastating situation. The lead author of the study concludes, “Neonicotinoids are highly likely to be responsible for triggering CCD” in previously healthy honeybee hives.
  • The study also points to the role cold weather plays in CCD. It seems the combination of insecticide exposure and cold winter weather is devastating to honeybee colonies. Something about the neonicotinoids causes the bees to abandon their hives during the winter months, and exposed to the elements, the bees die.
  • The study involved 18 honeybee colonies, six of which were treated with the insecticide imidacloprid, six with the insecticide clothianidin, and six were left untreated. As expected, all the bee populations diminished during the cold winter months, but in January, when the untreated colonies began to repopulate, the treated colonies continued to decrease in size. By spring, half the insecticide-treated colonies were gone.
  • Only one untreated colony of bees was lost – to parasite infestation. That finding doesn’t support earlier suggestions that insecticides might be making bees more vulnerable to parasites. The remaining bees in both treated and untreated colonies had the same levels of parasite infestation.
  • Future studies will hopefully identify the biological mechanism responsible for the link between neonicotinoid insecticides and CCD.

By Dr. Becker

As many of you are aware and may have read about in Dr. Mercola’s articles (“Beekeeping Industry Doomed - Might We See Destruction of Food Supply Before the End of This Decade?,” “Bees Dying By the Millions,” “The Tragic Mistake That Now Threatens 1 Out of Every 3 Bites You Eat”), for several years now the earth has experienced an unprecedented loss of honeybees to a condition known as Colony Collapse Disorder (CCD). A recently published study on the subject provides further evidence that the widespread use of neonicotinoids, a class of insecticides, is harming the bees, especially during winter months.

According to lead study author Chensheng Lu of the Harvard School of Public Health, in a press release:

"We demonstrated again in this study that neonicotinoids are highly likely to be responsible for triggering CCD in honey bee hives that were healthy prior to the arrival of winter.”

Neonicotinoids are nicotine-like chemicals and are the most widely used class of insecticides in the world today. It’s hard to find pest control products that don’t contain at least one neonicotinoid insecticide.

According to the Harvard study, it seems at least two kinds of neonicotinoids cause bees to desert their hives during cold winter months. Without the protection of their hives, the bees die.

6 of 12 Bee Colonies Treated with Insecticides Disappeared During the Winter of 2012

The study looked at two insecticides, imidacloprid and clothianidin, and the results are the same as those of a 2012 study that focused only on imidacloprid. The earlier study concluded the same thing – the chemical caused honeybees to abandon their hives once winter arrived.

Lu and study co-authors from the Worcester County Beekeepers Association monitored 18 bee colonies in three locations in central Massachusetts from October 2012 through April 2013. At each location, the researchers separated six colonies into three groups. One group was treated with imidacloprid, one with clothianidin, and the third, the control group, was left untreated.

As would be normal during a cold winter in Massachusetts, all the bee colonies decreased in size. But by January 2013, bee populations in the untreated groups began to grow, while populations in both insecticide-treated colonies continued to diminish.

By the time spring arrived, half the insecticide-treated colonies were gone, their hives empty.

Study Also Suggests Insecticide Exposure Does NOT Make Honeybees More Vulnerable to Parasites

Interestingly, the number of bees lost during the Harvard study was less than in the 2012 study, in which over 90 percent of the insecticide-treated colonies were lost. The researchers think the difference is due to the fact that the winter of 2011-2012 was extraordinarily long and cold. It’s likely the combination of frigid conditions and exposure to the neonicotinoids is responsible for the very high die off in 2012.

In the Harvard study, only one of the six untreated colonies was lost, and it appeared thousands of those bees died from a parasite infestation. That finding doesn’t support earlier suggestions that insecticides could be making bees more vulnerable to parasites. The remaining bees in both treated and untreated colonies had the same levels of parasite infestation.

Unfortunately, despite mounting evidence that neonicotinoid insecticides are directly involved in Colony Collapse Disorder in honeybees, we don’t yet know why. Hopefully, future research will identify the biological mechanism responsible for the link between these insecticides and CCD. But even without a defined biological mechanism, it’s clear the widespread use of neonicotinoids is playing a pivotal role in the potentially devastating disappearance of honeybees from the earth.

Download the full study here.

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