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More Evidence Rises Of Role Pesticides Play In Bee Colony Collapse

April 8, 2012

Lee Rannals for RedOrbit.com

As bee populations continue to decline, researchers are scurrying to try and find an answer as to why.

A new study from Harvard School of Public Health has linked one of the most widely used pesticides, imidacloprid, as the bee’s nemesis.

The authors wrote in a paper being published in the Bulletin of Insectology that they have found “convincing evidence” of the link between imidacloprid and Colony Collapse Disorder (CCD), in which adult bees abandon their hives.

“The significance of bees to agriculture cannot be underestimated,” Alex Lu, associate professor of environmental exposure biology in the Department of Environmental Health, said in a press release. “And it apparently doesn’t take much of the pesticide to affect the bees. Our experiment included pesticide amounts below what is normally present in the environment.”

The team conducted a study in Worcester County, Massachusetts to try and replicate how imidacloprid may have caused the CCD outbreak.

They monitored bees in four different bee yards, each of which had four hives treated with different levels of imidacloprid and one control hive.

After a 12-week period of imidacloprid dosing, all the bees were alive.  However, after a 23-week period, 15 out of 16 of the imidacloprid-treated hives had died.  The bees that were exposed to the higher levels of the pesticide died first.

The Harvard study is just one of many that have been recently published that blame neonicotinoid-type pesticides as the leading culprit behind the dwindling bee population.

Eric Mussen, Extension Apiculturist and resident bee keeper at the University of California Davis, told RedOrbit in an email during one of the neonicotinoid studies that returning to the days when bees were flourishing may not be possible.

“It may not be possible to return to the good old days,” Mussen said. “Many areas of excellent bee forage have become housing developments, farms, airports, highways, shopping centers, theaters, sports arenas, etc.”

He said even undisturbed areas that used to have plenty of flowers for bees to pollinate now have “sparse numbers of plants on them.”

Scientists have been trying to pin down the likely culprit of CCD since they found that between 30 and 90 percent of honey bee colonies have been lost since 2006.

Mussen said other factors that play a role in the loss of honey bees is a dwindling of food resources for the colonies.

“Honey bees are most robust and can fend off diseases, parasites and toxicants when they are at their physiological best,” Mussen told RedOrbit. “The proteins, vitamins, minerals, lipids, carbohydrates, sterols, antioxidants, etc. in a healthy mix of pollens are essential to rearing and maintaining healthy bees.”

“The introduction of formerly exotic mites and diseases into the honey bee population has presented more challenges than exposures to pesticides.  However, as pesticides continue to be formulated to be more effective target pest eliminators, they tend to impact non-targets more, as
well.”

According to Mussen, if we were to allow nature to take its course and stop using chemical mite control, then we may end up with mite-tolerant bees, but we would have lost billions of dollars in crop industry.

Scientists, conservationists, and farmers are working hard to try and understand how pesticides, diseases and habitat loss are affecting bee population.  They are also trying to find new ways to develop landscapes that are more bee friendly, according to what researchers wrote in the paper “The Plight of the Bees” published the journal Environmental Science & Technology

They said individuals can modify their landscapes to make them healthier for bees, “whether that landscape is public rangeland in Wyoming or a flower box in Brooklyn.”

“It also is possible to reduce agriculture and urban pesticide use to mitigate bee poisonings,” the authors wrote. “We can engage in the sustainable management of honey bees and native bees.  Promoting the health of bee pollinators can begin as an individual or local endeavor, but collectively has the far-reaching potential to beautify and benefit our environment in vital and tangible ways.”

EASTER EGG: RE


Source: Lee Rannals for RedOrbit.com



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