The mysterious vanishing of honeybees from hives can be directly linked to insecticide use, according to new research from Harvard University. The scientists showed that exposure to two neonicotinoids, the world’s most widely used class of insecticide, lead to half the colonies studied dying, while none of the untreated colonies saw their bees disappear…
The loss of honeybees in many countries in the last decade has caused widespread concern because about three-quarters of the world’s food crops require pollination. The decline has been linked to loss of habitat, disease and pesticide use. In December 2013, the European Union banned the use of three neonicotinoids for two years.
In the new Harvard study[.pdf], published in the Bulletin of Insectology, the scientists studied the health of 18 bee colonies in three locations in central Massachusetts from October 2012 till April 2013. At each location, two colonies were treated with realistic doses of imidacloprid, two with clothianidin, and two were untreated control hives.
“Bees from six of the 12 neonicotinoid-treated colonies had abandoned their hives and were eventually dead with symptoms resembling CCD,” the team wrote. “However, we observed a complete opposite phenomenon in the control colonies.” Only one control colony was lost, the result of infection by the parasitic fungus Nosema and in this case the dead bees remained in the hive.
Previously, scientists had suggested that neonicotinoids can lead to CCD – colony collapse disorder – by damaging the immune systems of bees, making them more vulnerable to parasites and disease. However, the new research undermines this theory by finding that all the colonies had near-identical levels of pathogen infestation…
“Sudden deaths of entire honey bee colonies is a persistent concern in North America,” said Paul de Zylva, Friends of the Earth’s senior nature campaigner. “Comprehensive research into the role pesticides play in bee decline is urgently required – including how they may compound other pressures, such as a lack of food and loss of habitat.” Lu agreed: “Future research could help elucidate the biological mechanism that is responsible for linking sub-lethal neonicotinoid exposures to CCD. Hopefully we can reverse the continuing trend of honeybee loss.”
In April, a landmark European study revealed the UK is suffering one of the worst rates of honeybee colony deaths in Europe. “The UK government [which opposed the EU’s neonicotinoid ban] has accepted the need for a national action plan to reverse bee and pollinator decline,” said de Zylva. “But its draft plan is dangerously complacent on pesticides, placing far too much trust in chemical firms and flawed procedures.”
Except for centers of excellence maintaining dedication to scientific methods, we seem incapable in the United States of examining critical questions outside of going hat-in-hand to the corporations which very often are the cause of whichever disaster under examination.
There is little reason other than political cowardice stateside for the European Union [for example] to be demonstrating leadership in the quest to solve honeybee colony collapse disorder. We’re the largest producer of agriculture on the planet. We have the greatest stake in the whole process of feeding folks around the world. Yet, once again, our politicians are willing to impair that portion of our whole economy to please a group of corporate lobbyists.
