By Alan Boyle, Science Editor, NBC News
This past winter has been exceptionally rough for honeybees — and although it's too early to say exactly why, the usual suspects range from pesticides that appear to cause memory loss to pests that got an exceptionally early start last spring.

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Steve Corniffe works on collecting honey produced by the bees at the J & P Apiary and Gentzel's Bees, Honey and Pollination Company on April 10, 2013 in Homestead, Fla.

Friday marked the start of an annual survey that asks beekeepers to report how many bees they lost over the winter, conducted by the Bee Informed Partnership, the Apiary Inspectors of America and the U.S. Department of Agriculture. The advance word is that the results will be brutal.  The New York Times, for example, quoted beekeepers as saying the losses reached levels of 40 to 50 percent — which would be double the average reported last year.

Joe Raedle / Getty Images

John Gentzel collects honey in Homestead, Fla. Honey bee owners along with scientists continue to try to figure out what is causing bees to succumb to the colony collapse disorder which has devastated apiaries around the country.

One beekeeper in Montana was quoted as saying that his bees seemed healthy last spring, but in September, "they started to fall on their face, to die like crazy." Read full story.

Joe Raedle / Getty Images

Honey bees are seen at the J & P Apiary and Gentzel's Bees, Honey and Pollination Company in Homestead, Fla. Reports indicate that the disorder which kills off thousands of bees at a time has resulted in the loss of some 30 percent of honey bee populations among beekeepers since 2007.

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Vincent Kessler / Reuters

A coloured honeycomb from a beehive is seen in Ribeauville near Colmar Eastern France, on Oct. 5. Bees at a cluster of bee hives in northeastern France have been producing honey in mysterious shades of blue and green, alarming their keepers who now believe residue from containers of M&M's candy processed at a nearby biogas plant is the cause. Since August, beekeepers around the town of Ribeauville in the region of Alsace have seen bees returning to their hives carrying unidentified colourful substances that have turned their honey unnatural shades.

Vincent Kessler / Reuters

French apiarist Andre Frieh holds a sample green colored honey at his home in Ribeauville near Colmar Eastern France, on Oct. 5.

Reuters -- Bees at a cluster of apiaries in northeastern France have been producing honey in mysterious shades of blue and green, alarming their keepers who now believe residue from containers of M&M's candy processed at a nearby biogas plant is the cause.

Since August, beekeepers around the town of Ribeauville in the region of Alsace have seen bees returning to their hives carrying unidentified colorful substances that have turned their honey unnatural shades.

Mystified, the beekeepers embarked on an investigation and discovered that a biogas plant 4 km (2.5 miles) away has been processing waste from a Mars plant producing M&M's, bite-sized candies in bright red, blue, green, yellow and brown shells. Asked about the issue, Mars had no immediate comment.

The unsellable honey is a new headache for around a dozen affected beekeepers already dealing with high bee mortality rates and dwindling honey supplies following a harsh winter, said Alain Frieh, president of the apiculturists' union.

Agrivalor, the company operating the biogas plant, said it had tried to address the problem after being notified of it by the beekeepers.

Read the full story.

Related links on PhotoBlog:

• Swarm of thousands of bees delays Pittsburgh flight
• 'Buzzing' over the newest residents atop NYC hotels
• Beekeeper suits up in 73-pound coat of bees

Vincent Kessler / Reuters

The village of Ribeauville is seen near Colmar Eastern France, on Oct. 5.

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Stephen Repasky / AP

Thousands of bees swarm on the wing of a Delta Air Lines flight at Pittsburgh International Airport in Pittsburgh. The flight from Pittsburgh to New York was delayed until Repasky, a beekeeper, was called in to remove them.

Justin Merriman / AP

A beekeeper, gathers up bees that swarmed on the wing of a Delta Air Lines flight.

Master beekeeper Stephen Repasky tells KDKA-TV he was called out on Wednesday when the bees gathered on the wing of the plane as crews were getting ready to fuel the plane.

Repasky says such swarms form when colonies become too large and the queen leaves half of her bees behind to find a new home. Some swarms can contain 25,000 to 30,000 bees.

-- Reported by the Associated Press

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China Daily via Reuters

An apprentice uses burning incense to drive bees away from She Ping's face during a world record attempt in Chongqing Municipality, China, on April 18, 2012.

China Daily via Reuters

A Chinese beekeeper covered his body with 73 pounds (33.1 kg) of bees — that's an estimated 331,000 of the creatures — during a world record attempt on Wednesday, Reuters reports.

Local media reported that She Ping, 32, had broken the previous world record of 59 pounds (26.8 kg) of bees which had been set by another Chinese beekeeper, Ruan Liangming, in 2008.

However, the Guinness World Records website does not mention either man, instead awarding its "Heaviest mantle of bees" honor to Vipin Seth, an Indian whose burden is said to have weighed 136 lb 4 oz (61.4 kg). Could She Ping's brave attempt have been in vain?

China Daily via Reuters

Local media reported that She had set a new world record.

Slideshow: Guinness World Records 2012

Navesh Chitrakar / Reuters

Look through images of the biggest, fastest, longest, weirdest and wackiest record breakers from the 2012 edition of Guinness World Records.

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Matthias Hiekel / AFP - Getty Images

Crocuses are covered with raindrops on Feb. 28 in Dresden, eastern Germany. First signs of spring come up across the country.

Ali Jarekji / Reuters

A bee collects pollen from an almond blossom in early spring at park in Amman, Jordan, on Feb. 28.

Just a few weeks ago Europe was going through a bitter winter, which seemed to have no end in sight. Now, the first signs of spring are popping up with blooming crocuses, and there are still three weeks left before the official start of spring.

We have experienced a mild winter so far in the New York City area, and while the lack of snow is a little disappointing, it does not keep me from eagerly anticipating the warmer weather.

Are you looking forward to the spring? Still want more winter? Take a look at some of the best winter images this season in our slideshow:

Slideshow: Winter wildness

Petr Josek / Reuters

Winter has arrived with chilling force in many parts of North America, Europe and Asia.

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