Farmers may have to get out their feather dusters and do some manual pollinating if the millions of bees that have vanished in the U.S. don't show up soon.

A chain is only as strong as the weakest link. What happens to our food supply, without the humble bee?

Honeybees are vanishing at an alarming rate from 24 US states, threatening the production of numerous crops.

The cause of the losses, which range from 30% to more than 70%, is a mystery, but experts are investigating several theories.

American bee colonies have been hit by regional crises before, but keepers say this is the first national crisis.

Bees pollinate more than $14bn (£7bn) worth of US seeds and crops each year, mostly fruits, vegetables and nuts.

The mystery disappearances highlight the important link that honeybees play in the chain that brings fruit and vegetables to supermarkets and dinner tables.

The crisis threatens numerous crops, from avocados to kiwis and California almonds - one of the most profitable in the US.

"I have never seen anything like it," California beekeeper David Bradshaw, 50, told the New York Times.

"Box after box after box are just empty. There's nobody home."

...The investigators are exploring a range of possibilities to explain the losses, which they are calling "colony collapse disorder". These include viruses, a fungus and poor bee nutrition.

They are also studying pesticides banned in some European countries to see if they are affecting the bees' innate ability to navigate their way back to their hives. - BBC (see also NY Times)

According to at least one urban legend, Einstein once remarked that "if bees were to disappear, man would only have a few years to live."

Hmm... how about a farming system without chemicals? Any takers?

Update: Colony Collapse Disorder - a Moment for Reflection? 

Further Reading:

• National Honey Board Funds Research For Mysterious Honey Bee Disease
• The Vanishing
• Insecticide Ban as Billions of Bees Die (France 2004)