Pesticide and Beehive Collapse

SOURCE: Ken Taylor (
SUBHEAD: Harvard adds another study showing nicotine based pesticide's big impact on bees colonies.  

By Alan Harmon 5 April 2012 in Ezezine -  

Image above: Ad from a website connecting international buyers with Imidacloprid insecticide manufacturers in China. From (  

Imidacloprid, one of the most widely used insecticide, has been named as the likely culprit in the sharp worldwide decline in honey bee colonies since 2006. It took only low levels of imidacloprid to cause hive collapse, less than what is typically used in crops or in areas where bees forage.

Researchers at the Harvard School of Public Health say their new research provides “convincing evidence” of the link between imidacloprid and colony collapse disorder.

“It apparently doesn't take much of the pesticide to affect the bees,” says Alex Lu, associate professor of environmental exposure biology at Harvard’s Department of Environmental Health,
"Our experiment included pesticide amounts below what is normally present in the environment.”

The research results will appear in the June issue of the Bulletin of Insectology. Lu and his research team hypothesized that the uptick in CCD resulted from the presence of imidacloprid, a neonicotinoid introduced in the early 1990s. Bees can be exposed in two ways – through nectar from plants or through high-fructose corn syrup beekeepers use to feed their bees.

As most U.S.-grown corn has been treated with imidacloprid, it's also found in corn syrup. In the summer of 2010, the researchers conducted an in situ study in Worcester County, Mass. aimed at replicating how imidacloprid may have caused the CCD outbreak. Over a 23-week period, they monitored bees in four different bee yards; each yard had four hives treated with different levels of imidacloprid and one control hive.

After 12 weeks of imidacloprid dosing, all the bees were alive. But after 23 weeks, 15 out of 16 of the imidacloprid-treated hives – 94% – had died. Those exposed to the highest levels of the pesticide died first. Lu says the characteristics of the dead hives were consistent with CCD – the hives were empty except for food stores, some pollen, and young bees, with few dead bees nearby.

When other conditions cause hive collapse—such as disease or pests—many dead bees are typically found inside and outside the affected hives. Strikingly, said Lu, it took only low levels of imidacloprid to cause hive collapse, less than what is typically used in crops or in areas where bees forage.

UK Officials Turn Blind Eye To Problem
Meantime, the UK Crop Protection Association has rejected calls for a ban on certain insecticidal seed treatments, instead moving to highlight the regulatory controls and stewardship advice in place to protect the health and welfare of bees. “Science-based statutory controls on pesticide approval at EU and UK level include a specific assessment of any potential risks to bee health, and ensure that when approved products are used as directed there should be no adverse effects on bee populations,” association chief executive Dominic Dyer says.
“The crop protection sector recognizes the critical importance of bees as a pollinator for agriculture and food production, and the industry has committed a significant level of resource and expertise to support ongoing research and stewardship programs aimed at protecting bee health.”
Dyer says that over the last 18 months, the association has distributed more than 100,000 of its “'Bee Safe, Bee Careful” advisory booklets aimed at farmers, spray operators and beekeepers. “We have spoken directly to hundreds of beekeepers up and down the country about the vital importance of crop protection and our industry's commitment to protecting bees,” he says.
“This is a key part of our wider commitment to ensure the safe and responsible use of pesticides.”
The association says it recently issued a new pesticides and bees garden booklet, supported by the British Bee Keepers Association and the Royal Horticultural Association, that will be widely available to the public at garden centres around the country. “Most experts agree that the decline in bee populations is down to the Varroa mite and other parasitic diseases, combined with the problems associated with habitat loss, colony stress and climate change,” Dyer claims.
“We must that ensure that research effort and resource are not deflected away from these pest and environmental issues which together present the major underlying challenges to bee health.”
Dyer warned that the removal of certain insecticidal seed treatments could result in unnecessary crop losses without any benefits for bee health. “Where temporary restrictions have been imposed on these products in France and Germany, there has been no improvement in bee health and the regulatory authorities have now re-approved their use,” he says.
“These products are also widely used in Australia, which has one of the healthiest bee populations in the world. A ban on the use of these seed treatment products will not improve bee health, but would result in the loss of a very sustainable and environmentally friendly form of crop protection technology that is vital for food production in the UK and around the world.”
See also:
Ea O Ka Aina: KCC Beekeeping Class 4/24/12
Ea O Ka Aina: Nicotine Pesticides and Bees 12/13/11
Ea O Ka Aina: Neoicotinoid pesticides kill bees 1/24/11


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