Do people know perfectly well what's killing bees?S

Many people don't think that the collapse of bee populations is as big a mystery as it's made out to be. An EPA memo, leaked last month, reveals that a commonly used pest-control chemical can disrupt bee colonies.

This substance, sold in the USA as clothianidin, disrupts the nervous system of insects, and it's been a suspect in the mass death of honey bees for years. It's still available widely. Recent documents intimate that the EPA has known for a long time the chemical could be harmful to bees, but has kept it on the shelves while bee populations plummet.

This class of pesticides, known as neonicotinoids, attacks the nervous system of insects, killing them off, while having little effect on other animals. This makes them excellent pest control — so excellent that many seeds are sold treated with neonicotinoids. The plant grows with the pesticide inside it, allowing it to kill all the insects which attack it.

Unfortunately, the neonicotinoids are present in the pollen and nectar of flowers, which are fed on by honeybees. One of the most potent neonicotinoids is clothianidin, sold since the early 2000s by Bayer Cropscience. Many believe that clothianidin is responsible for the collapse of hives, and that the EPA has allowed it to continue to be sold despite mounting evidence as to its effect and faulty studies conducted by Bayer showing its safety.

There is some pretty suspicious timing. The first neonicotinoid was released in 1994. In 2001 a French study showed that bee population weight per hive dropped by over one half between 1995 and 2001. The country banned the use of the pesticide containing neonicotinoids in crops like corn, which provided the bulk of the insects' food.

Bayer Cropsource came out with an extremely potent neonicotinoid, clothianidin, in 2003. In 2005, according to Hive Collapse experts, the US bee population started dying off.

In 2008, some farmers in Germany accidentally released clothianidin into the air. Two thirds of the region's bees died. Germany stopped using clothianidin. Italy stopped using clothianidin in 2008 as well, and saw stable bee population in neonicotinoid-free areas in 2009.

The EPA did require Bayer to furnish a study on the effect of clothianidin on bee populations. However, it was only required to do so after clothianidin hit the shelves in 2003. The study was expected by 2004. It came out in mid-2007. And many experts found the study to be lacking — some problems with it include an assumed range area of two acres when bees actually range two miles, and it supplied them with clothianidin-treated canola when a main source of sustenance is corn. The bees in the study would have gathered a much smaller supply of clothianidin than regular bees.

Then in 2010 a beekeeper named Tom Theobald wrote an article about clothinidin. An EPA employee contacted him and let him know that the EPA itself had reviewed the Bayer clothianidin study and found it to be unsound. Theobald requested documentation of this, and received it. The EPA had found that the study was not sufficient, and another one was needed to show that clothianidin was safe. This is going on eight years since Bayer was granted the right to sell clothianidin, on the understanding that a valid study would be published in 2004.

The bee die-off does not just make for a lack of honey in the world. Bees are hugely important pollinators, and are responsible for the pollination of one third of America's agricultural output. This is a problem at a time when the world's population is set to hit seven billion and food prices are reaching a record high due to worldwide crop failures. What's the alternative to using bees for pollination? One beekeper has a suggestion:

Certainly, the bee could be replaced as a pollinator? [Thomas] Theobald said the Chinese have tried replicating bees` efforts, to no avail — using their vast population, holding chicken feathers on bamboo poles to individually pollinate crops by hand.

"That`s another job Americans won`t do," Theobald commented. "You can't pollinate foods and sustain a population of 300 million with chicken feathers on bamboo poles."

[Via Fast Company times two, The Financial Times, The Estes Park Trail Gazette, and EPA.]