New evidence for ‘chemical cocktail’ effect in bee deaths

You might feel differently if you’ve been stung by one, but there are few things I find sadder than honey bees dying in mass numbers. So why are they dying?  Pesticides Action Network provided this explanation.

Finding an average of 8 different pesticides — at times up to 31 — in honeybee hives, a new study illuminates the “unprecedented” pesticide load place on bees and other pollinators, according to ScienceNews. Noting that the mix, or synergistic effects, of the pesticide burden borne by bees may be much more harmful than any one chemical exposure alone, scientists from the American Chemical Society called “for emergency funding to address the myriad holes in our scientific understanding of pesticide consequences for pollinators.”

Past Food and Faith posts on bee deaths (most recent at top):

And here is the video from that latest post:

Getting back to the study –
Over two years, scientists analyzed pollen, wax, and live bees from both healthy bee colonies and those suffering from Colony Collapse Disorder – a mysterious disease responsible for decimating over a third of the U.S. honeybee population since 2006. The results show that not only are hives contaminated by record numbers of crop pesticides and mite-killing chemicals, but that these chemicals may be interacting in very harmful and unknown ways. In beeswax samples, the study found that “87 pesticides and metabolites were found with up to 39 different detections in a single sample,” including the breakdown products of the contaminants, some of which do more damage their the chemicals in their original forms. Among the pesticides most commonly found: chlorpyrifos, endosulfan and atrazine.

Researchers also found that in may cases, the bees’ homes (wax and pollen) were far more contaminated than the live bees themselves, but supposed that the difference was due to the fact that the sample bees were mostly queens, brood nurses and adolescents – not the worker bees who are, “on the chemical frontlines, foraging in pesticide treated fields.” In fact the study found very few healthy worker bees in the hives, indicating that the poisoned foragers likely die before they ever make it home. And direct mortality, the researchers noted, is not the primary risk of this toxic load. Little is known about how miticides, a chemical applied to kill parasitic bee mites, interact with crop pesticides, and the scientists involved say that, “these miticides may, when paired up with other classes of pesticides, act synergistically to poison insects.” Even the healthy colonies that were studied, only 1 wax sample, 3 pollen samples and 12 bees were found to be free of detectable pesticides. Even the sub-lethal impacts of these chemical cocktails, which affect honey bee learning, orientation and immune system functioning, will have devastating effects on the $14 billion worth of U.S. crops that depend on these pollinators each year.

Pesticides Action Network is asking its members to advocate for a ban on Chlorpyrifos

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