by Larry Powell
After conducting various field studies, Bayer concludes, "Sivanto displayed a very promising safety profile." The company concedes, it works in ways similar to the neonicotinoids (a group of insecticides which has become notorious for its likely role in pollinator decline). Still, it finds, the product "can be considered safe to most beneficial insects, specifically pollinators."
|Image by Brian Robert Marshall.|
|But a team of scientists
at the University of California, San Diego, reaches a different conclusion. In findings published earlier this year, the team gave
a range of Sivanto doses to the bees, including ones they
encounter in the field. By itself, the chemical did not appear to be harmful.
But, when combined with the fungicide propiconazole (brand name "Banner
Maxx"), widely-used by farmers, the harm was "greatly
amplified." The bees either sickened or died, apparently because the fungicide
weakened their ability to shake off the toxicity. It's not uncommon for
pollinators to be subjected to a dizzying array of pesticides all at once,
while foraging in the fields. It’s a process called "synergism," in
which they can suffer harm they would not, if exposed
to just a single one.
The spokesperson for the team, Dr. Simone Tosi, tells PinP, she does not believe that regulations in the US require manufacturers to test for synergistic effects when they apply to have their products approved. But neither does she think that such regulations prohibit such testing.
In a news release, her team says, "We believe this work is a step toward a better understanding of the risks that pesticides could pose to bees and the environment. Our results highlight the importance of assessing the effects pesticides have on the behaviour of animals, and demonstrate that synergism, seasonality and bee age are key factors that subtly change pesticide toxicity." They call for further studies to better assess the risks to pollinators.
But at least one of those other studies has already been done. It, too, comes up with similarly negative conclusions. A team from three German universities has found that flupyradifurone binds to the brain receptors of honeybees, damaging their motor skills.
Meanwhile, Bayer's marketing plans for its new product are ambitious. It promises to "develop, register and sell" Sivanto in many places across the world, including the US, Europe, Asia, Ghana and Brazil. While Canada isn't mentioned, specifically, there seems little doubt it will end up here, too. The company wants to see its product "in all major climatic zones allowing agriculture."
Apart from a couple of automated responses, I have gotten no substantive answers.