A friend pointed me to an article in Southern Studies that suggests there are new clues in the race to find the cause of massive bee death:

Five years ago, EPA registered a new pesticide known as clothianidin under the condition that the manufacturer — North Carolina-based Bayer CropScience — submit studies about the product’s effect on bees. The NRDC requested those studies from the EPA under the Freedom of Information Act, but the agency has declined to disclose them.

The significance of this has been handled very differently elsewhere. Most of the article seems to be a reprint of information found in The Guardian:

Tests on dead bees showed that 99% of those examined had a build-up of clothianidin. The chemical, produced by Bayer CropScience, a subsidiary of the German chemical giant Bayer, is sold in Europe under the trade name Poncho.

[…]

The company says an application error by the seed company which failed to use the glue-like substance that sticks the pesticide to the seed, led to the chemical getting into the air.

That sounds very conclusive. Why is the US so slow to act? The harm to bees surely outweighs the harm to pesticide companies. The Southern Studies article suggests one of every three mouthfuls of food in America is owed to bee pollination. It does not say how many are owed to pesticides. The Guardian presents two sides of the story:

Bayer has always maintained that imidacloprid is safe for bees if correctly applied.

[…]

Philipp Mimkes, spokesman for the German-based Coalition Against Bayer Dangers, said: “We have been pointing out the risks of neonicotinoids for almost 10 years now. This proves without a doubt that the chemicals can come into contact with bees and kill them. These pesticides shouldn’t be on the market.”

I guess it just depends on whether those regulating the market care more about long term safety and security of the environment, or more about Bayer’s bottom line. France and Germany have banned the pesticides, while the US seems unsure how to manage risk of colony collapse when profits are on the line.