Here's Why All the Bees Are Dying

Bees are having a really hard time right now. For about a decade, they've been dying off at an unprecedented rate—up to 30 percent per year, with a total loss of domesticated honeybee hives in the United States worth an estimated $2 billion.

At first, no one knew why. But as my colleague Tom Philpott has reported extensively, in the last few years scientists have accumulated a compelling pile of evidence pointing to a class of insecticides called neonicotinoids. These chemicals are widely used in commercial agriculture but can have lethal effects on bees. Other pesticides are also adding to the toll. So are invasive parasites and a general decline in the quality of bees' diets.

Everything You Wanted to Know About the Bee Die-Off

For years, honeybees were dying, and no one knew why.

There have been some glimmers of hope recently. The number of bee deaths wasn't as dramatic last winter. Studies began pointing the finger at pesticides.

But a simple fact remains: Bees still are on the decline, and no one's sure why.

They're dying in large numbers, and scientists are scrambling to identify the cause. Beekeepers used to see about 5 or 10 percent of the bees in their hives die every year, but starting in 2006, losses jumped to 30 percent. About 10 million beehives, worth an estimated $2 billion, have been lost since then. The numbers are down slightly for last winter, when beekeepers lost about 23 percent.

Bee Deaths From Colony Collapse Disorder On The Rise As Researchers Point To Pesticides

Honeybee deaths are on the rise across the world, and researchers are working to find the cause. With as many as 40 or 50 percent of commercial U.S. bee hives lost to colony collapse disorder, according to the New York Times, scientists are eyeing a relatively new class of pesticides as a likely culprit.

Neonicotinoids, which are chemically similar to nicotine, have already been shown to interfere with bees' capacity to learn scents, hampering their efforts to collect food.

Insecticide 'unacceptable' danger to bees, report finds

The world's most widely used insecticide has for the first time been officially labelled an "unacceptable" danger to bees feeding on flowering crops. Environmental campaigners say the conclusion, by Europe's leading food safety authority, sounds the "death knell" for the insect nerve agent.

The chemical's manufacturer, Bayer, claimed the report, released on Wednesday, did not alter existing risk assessments and warned against "over-interpretation of the precautionary principle".

Mystery of the disappearing bees: Solved!

If it were a novel, people would criticize the plot for being too far-fetched – thriving colonies disappear overnight without leaving a trace, the bodies of the victims are never found. Only in this case, it’s not fiction: It’s what’s happening to fully a third of commercial beehives, over a million colonies every year. Seemingly healthy communities fly off never to return. The queen bee and mother of the hive is abandoned to starve and die.

Thousands of scientific sleuths have been on this case for the last 15 years trying to determine why our honey bees are disappearing in such alarming numbers. “This is the biggest general threat to our food supply,” according to Kevin Hackett, the national program leader for the U.S. Department of Agriculture’s bee and pollination program.

Are Pesticides Behind Massive Bee Die-Offs?

For the  German chemical giant Bayer, neonicotinoid pesticides—synthetic derivatives of nicotine that attack insects' nervous systems—are big business. In 2010, the company reeled in $789 million euros (more than $1 billion) in revenue from its flagship neonic products imidacloprid and clothianidin. The company's latest quarterly report shows that its "seed treatment" segment—the one that includes neonics—is booming. In the quarter ended Sept. 30, 2011, sales for the company's seed treatments jumped 28 percent compared to the same period the previous year.

Such results no doubt bring cheer to Bayer's shareholders. But for honey bees—whose population has come under severe pressure from a mysterious condition called colony collapse disorder—the news is decidedly less welcome. A year ago on Grist, I told the story of how this class of pesticides had gained approval from the EPA in a twisted process based on deeply flawed (by the EPA's own account) Bayer-funded science. A little later, I reported that research by the USDA's top bee scientist, Jeff Pettis, suggests that even tiny exposure to neonics can seriously harm honey bees.

Now a study from Purdue researchers casts further suspicion on Bayer's money-minting concoctions. To understand the new paper—published in the peer-reviewed journal Plos One—it's important to know how seed treatments work, which is like this: The pesticides are applied directly to seeds before planting, and then get absorbed by the plant's vascular system. They are "expressed" in the pollen and nectar, where they attack the nervous systems of insects. Bayer targeted its treatments at the most prolific US crop—corn—and since 2003, corn farmers have been blanketing millions of acres of farmland with neonic-treated seeds.