Massive honey bee die-offs on Vancouver Island and around North America and Europe could be the result of more than mite infestations and difficult winters, according to Harvard scientists.
In research results published in the journal Science last month, scientists with the Harvard School of Public Health believe that miniscule doses of a common neonicotinoid pesticide can have a detrimental effect on the nervous system of bees.
The pesticides are often used as a coating on seeds, including corn seeds. In dry conditions or during the planting process, the pesticides can be released into the environment, and further studies are being carried out to determine if pesticides remain in the plant as it grows, creating a further hazard to bees searching for food.
Managers of large honey bee operations are also known to use corn syrup to feed bees, and it was discovered that trace amounts of the pesticide make it through the process that creates corn syrup into the final product.
The pesticide affects the bees' nervous systems, disabling their homing mechanisms they rely on to navigate their way home. Worker bees, sent to collect nectar, die without being able to deliver food back to the hive. The result is a slow collapse of the colony over several months, an event scientists call Colony Collapse Disorder.
In 2010, Vancouver Island bees suffered with populations being decimated by as much as 90 per cent Islandwide, leaving the 1,000 or so registered beekeepers stunned. While numbers picked up marginally in 2011, this year's numbers are still down considerably with estimates between 50 and 60 per cent, and beekeepers are in the unfamiliar position of having to import bees rather than export them.
Brenda Jager, bee inspector for the B.C. Ministry of Agriculture and Lands for Vancouver Island and the Gulf Islands, says most bee operations on Vancouver Island are small and are unlikely to use corn syrup because it is not readily available here, but that neonicotinoid pesticides are in the environment.
"There are some issues with the neonicotinoids in the environment," said Jager. "But I don't think it's a key reason for colony collapses on Vancouver Island. For the losses on Vancouver Island I wouldn't be able to correlate corn planting or pesticide prevalence with the deaths. It could be a factor as well as many other things. There isn't just one factor that is killing our bees."
Most Island bee keepers, she said, use a sugar solution to feed colonies. But she has also talked to local farmers, who say it is difficult to buy corn seed that is not coated, and therefore containing neonicotinoid pesticides.
Still, Jager says that weather here is a definite factor for colony collapses on Vancouver Island, resulting in a poor honey crop in 2011 and overall a poor season for bees.
"Because of that we expected poor winter survival and that has come to fruition this year," said Jager.
Sol Nowitz, owner of Jingle Pot Apiary, is one of the lucky beekeepers this year with losses in the normal range of about 15 per cent. In 2010, Nowtiz's colonies collapsed from about 200 down to 10. In 2011, he tweaked his tried-and-true beekeeping methods to adjust for current threats to his colonies.
He attributes Vancouver Island losses to recent cool winters, poor honey production, the import of southern hemisphere bees that don't do well in cold weather, and parasitic Varroa mites. But he also subscribes to the pesticide theory for large commercial beekeeping operations in the U.S.
"There is a likely connection," said Nowitz, who has been practising beekeeping for four decades. "Commercial beekeeping in the U.S. is done on a very large scale with bees being moved in huge numbers to pollinate a variety of mono culture crops. These crops provide bees with very little nutrition ... and corn syrup may have to be fed to colonies."
The Harvard study is gaining traction elsewhere. Its results show a direct correlation between the amount of neonicotinoid pesticides colonies are exposed to and the survival rate of the colonies. Colonies around the world began to decline in 2006, not long after widespread use of neonicotinoid pesticides and coated seeds became common.
Jager said a study could be done here to confirm if neonicotinoid pesticides on Vancouver Island are partially responsible for colony collapses.
"Gardeners in their backyards, they're buying stuff that could be an issue," she said. "People need to be paying attention to what they're buying. I recently read that a lot of commercial people are buying seed that's coated and finding it's not working as well as they need it to and they're re-applying pesticides after the fact. Maybe we should be asking for seeds that aren't coated and demanding that from industry."
Eighty per cent of all B.C. crops, including fruits, vegetables, nuts and soy depend on bee pollination.
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