On Thursday, the Star Tribune carried Associated Press writer Seth Borenstein's article, Large study links key pesticide to weakened honeybee hives. Asked for comment by Borenstein, spokesters for Bayer and Sygenta polished a turd in the data and proclaimed neoicotinoids blameless.
It's still a turd. Borenstein reports:
A common and much-criticized pesticide dramatically weakens already vulnerable honeybee hives, according to a new massive field study in three European countries.
For more than a decade, the populations of honeybees and other key pollinators have been on the decline, and scientists have been trying to figure out what's behind the drop, mostly looking at a combination of factors that include disease, parasites, poor diet and pesticides. Other studies, mostly lab experiments, have pointed to problems with the insecticides called neonicotinoids, but the new research done in Britain, Hungary and Germany is the largest field study yet.
Researchers planted about 7.7 square miles (2,000 hectares) of fields of rapeseed, which is made into cooking oil, called canola in America. Some of the fields were planted with seeds treated with the insecticide, others with untreated seeds. The researchers followed bees from the spring of 2015 when the seeds flowered to the following spring when new bees were born.
The bee hives in the Hungarian and British fields that used pesticide-treated seeds did worse surviving through the next winter, the researchers found. In Hungary, the honeybee colonies near treated fields had 24 percent fewer worker bees the next spring when compared to those near untreated crops, according to a study published Thursday in the journal Science .
But in Germany, the bees didn't seem harmed. Hives there were generally healthier to start and when scientists analyzed the pollen brought back to the hives, they determined that the German bees ate a far broader diet with much less of their nutrition coming from the pesticide-treated rapeseed plants, said study director Richard Pywell. Only about 10 percent of the German bee diet was from neonicotinoid-treated plants, compared to more than 50 percent in Hungary and England, he said.
When hives are weakened by disease, parasites or bad diet — as many hives are worldwide — then the neonicotinoids "pushes them over the edge," said Pywell, a scientist at the Center for Ecology and Hydrology in England. So many of the British hives died, in both treated and untreated fields, that scientists couldn't calculate the specific effect of the insecticide, he said.
Of course, the pesticide manufacturers jumped on the health of the German hives, rather than the drastically smaller portion of neonic-treated plants in the German bees' diet. Borenstein:
Company officials pointed to the results in Germany and the lack of harm to hives there.
"The study shows that when hives are healthy and relatively disease free and when bees have access to diverse forage, neonics do not pose a danger to colony health," Bayer spokesman Jeffrey Donald wrote in an email.
In a statement, Syngenta's Peter Campbell, head of research collaborations, said the study "strongly suggests the effects of neonicotinoids are a product of interacting factors."
We can't wait for this shiny turd to drop at the Minnesota legislature, which gutted the Governor's proposal to study the effects of pesticides and habitat on pollinators. Now only habitat issues will be studied. Pay no attention to those pesticides or treated seeds, folks.
For another news report on the study, check out Field Studies Confirm Neonicotinoids’ Harm to Bees, where a scientist how peer reviewed the study was interviewed:
“It’s the biggest field trial anyone’s yet done on the impacts of normal farming use of neonicotinoids on bees,” University of Sussex bee biologist Dave Goulson, who reviewed the Pywell paper for Science but was not involved in the work, says of the European study. “It basically confirms what many previous studies have found, which is that normal farming use of these chemicals does indeed appear to harm wild bees and probably also honey bees.” . . .
Once the researchers determined the levels of pesticides to which honey bees are exposed in the field, they experimentally exposed the bees to artificial pollen containing similar levels of clothianidin, the most common pesticide they detected during their study, and examined the effects on bee health. Bees fed the neonicotinoid-laced pollen died younger than unexposed controls and also exhibited less “hygienic behavior”—that is, removing diseased or dead bees from the hive before infections can spread. Colonies fed the pesticide-laced pollen were also less likely than control colonies to have an egg-laying queen.
“I think it’s reached a point now where no reasonable person would deny that these chemicals are impacting on bees one way or another,” Goulson says. “Obviously, scientists would like to do more research, but at some point, you have to make decisions, and it seems to me that a pretty obvious decision needs making.”
Image: Turd polish, aka corporate spin.
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Bayer and Syngenta have been polishing that turd for years; the more they polish the more it stinks!
Posted by: Vaso | Jul 09, 2017 at 08:44 AM