August 25, 2009
Why Are Honey Bee Colonies Collapsing?
Damage to the honey bee's internal protein-producing "factories" may provide researchers with a new clue to the sudden collapse of honey bee colonies across the nation.
Colony collapse disorder is a phenomenon in which worker bees from beehives or colonies abruptly disappear.These disappearances have been happening since the dawn of apiculture, but the term "Ëcolony collapse disorder' was first used to describe a drastic increase in the number of disappearances of Western honey bee colonies in North America in late 2006.
Colony collapse has great economical implications, since many crops across the world are pollinated by bees.
No one quite knows why the colonies have suddenly collapsed, but researchers have theories that include viruses, mites, pesticides and fungi.
Fragments of ribosomal RNA were found in the gut of the sick bees, which according to the new study suggests that there had been damage to the ribosomes. Ribosomes make proteins essential for life.
The study, funded by the Department of Agriculture, was published in the Tuesday issue of Proceedings of the National Academy of Sciences.
Ribonucleic acid (RNA) is made from DNA, and is central to protein production.
The ailing bees were afflicted with an uncommonly high number of infections with viruses that target the ribosome, reported the researchers from the University of Illinois at Urbana-Champaign and the U.S. Department of Agriculture.
In a statement, the head of the department of entomology at the University of Illinois at Urbana-Champaign, May R. Berenbaum said, "If your ribosome is compromised, then you can't respond to pesticides, you can't respond to fungal infections or bacteria or inadequate nutrition because the ribosome is central to the survival of any organism. You need proteins to survive."
The researchers said the varroa mite, a parasite that infects the honey bee, was accidentally brought to the U.S. in 1986.
This reddish-brown mite carries picorna-like viruses that damage the ribosomes. Picornavirus literally means "small-RNA-virus". They cause a variety of diseases, ranging from acute "common-cold"-like illnesses, to poliomyelitis, and even chronic infections in livestock.
Researchers believe that the varroa mite may be the key factor leading to the breaking down of ribosomes.
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