For related articles and more information, please visit OCA’s Environment and Climate Resource page, and our Honey Bee Health & Colony Collapse Disorder page.

I reported in January, the USDA’s top bee researcher, Jeffrey Pettis, has publicly revealed that he has completed research showing that Bayer’s blockbuster neonicotinoid pesticides, used on million of acres of crops across the country, harm honeybees even at extremely low doses.

The revelation was significant because a growing number of U.S. beekeepers are worried that Bayer’s pesticides might be the key culprit in colony collapse disorder — the strange annual die-off of significant portions of the U.S. honeybee population. In December, a leaked document showed that EPA scientists had declared insufficient a previously accepted Bayer-funded study purporting to show that neonicotinoids don’t harm honeybees in farmfields.

News of Pettis’ as-yet-unpublished study has generated very little press in the United States beyond my coverage. In the United Kingdom, though, it’s made quite a splash — so much so that the USDA scientist got an invitation to address Parliament on the question of pesticides and bees. Pettis addressed Parliament on Monday, and the results were … odd. He distanced himself from calls to ban neonicotinoids. In an account of his testimony before Parliament, The Guardian quotes Pettis like this: “Pesticide is an issue but it is not the driving issue.”

On the other hand, though, he pointed to yet more evidence linking poor bee health to pesticides. According to The Guardian, in his testimony before Parliament, Pettis discussed a new phenomenon being observed by beekeepers: Bees are “entombing” or sealing off some pollen-filled cells in a hive. And when scientists test the sealed cells, they turn out to contain significantly higher levels of pesticides and other toxins than unblocked cells in the same hive.