(NaturalNews) Scientists remain stymied as honeybees in the United States and across the world continue to die in large numbers.
"There are a lot of beekeepers who are in trouble" said David Mendes, president of the American Beekeeping Federation. "Under normal condition you have 10 percent winter losses ... this year there are 30, 40 to 50 percent losses."
For many years, beekeepers have been plagued by colony collapse disorder, in which formerly healthy bees abruptly vanish from their hives. The number of beehives in the United States dropped 32 percent in 2007, another 36 percent in 2008 and still another 29 percent in 2009.
A number of explanations for the phenomenon have been suggested, including diseases, parasites, malnutrition, but toxic chemicals are emerging as a major concern among beekeepers.
"It might not be the only factor but it's a contributing factor," said Jeff Pettis of the U.S. Department of Agriculture's Bee Research Laboratory in Beltsville, Maryland.
A study recently published in the journal Public Library of Science found 121 different pesticides in 887 samples taken from beehives in 23 U.S. states and Canada.
"I don't put my bees in Florida because the last couple of years there has been tremendous increase in pesticide use in the orange crop to fight a disease," Mendes said.
"A few years ago they did not use any pesticide at all."
Pettis said that the destruction of natural lands is having a negative impact on the health of bees, which require a "diverse natural habitat."
"The world population growth is in a sense the reason for pollinators' decline," he said. "Because we need to produce more and more food to feed the world we grow crops in larger fields."
The irony, he noted, is that global agriculture depends heavily on honeybees to pollinate critical food crops.
"A growing world means growing more food and to do that we need pollinators," he said. "And the fact that the world is continuing to grow is the driving force behind the habitat destruction."