for National Geographic News
Bees, via pollination, are responsible for 15 to 30 percent of the food U.S. consumers eat. But in the last 50 years the domesticated honeybee populationwhich most farmers depend on for pollinationhas declined by about 50 percent, scientists say.
Unless actions are taken to slow the decline of domesticated honeybees and augment their populations with wild bees, many fruits and vegetables may disappear from the food supply, said Claire Kremen, a conservation biologist at Princeton University in New Jersey.
Anecdotes of farmers losing their crops owing to the honeybee shortage appear to be on the increase, Kremen said. Last February, for example, there were insufficient honeybees for all the almond blossoms in California. As a result some farmers failed to meet expected yields.
"There are shortages [like this] that pop up from time to time," Kremen said. "Whether there are more [shortages] than there were 20 years ago, one would guess yes, as there are fewer bees to go around, but it's not well documented."
Maryann Frazier, a senior extension associate in the department of entomology with Pennsylvania State University in State College, said honeybee shortages are not yet impacting commercial producers of crops, but that community farmers "are struggling to get bees for pollination."
In fact, Dewey Caron, an entomologist at the University of Delaware in Newark, started to study the problem of the honeybee decline when he noticed that farmers in the northeastern U.S. increasingly lacked sufficient bee colonies to meet their pollination needs.
"Growers didn't have options if they didn't like the quality [of the bees] they got from one fellow," he said. "So, we started to ask, Well, what is affecting the bees? What can we do to keep them healthier?"
The honeybee decline, which is affecting domesticated and wild bee populations around the world, is mostly the result of diseases spread as a result of mites and other parasites as well as the spraying of crops with pesticides, scientists say.
Among the greatest problems is the varroa mite, a bloodsucking parasite that attacks young and adult honeybees. Attacked bees often have deformed wings and abdomens and a shortened life span.
"The varroa mite is also really effective at transmitting disease, particularly viruses," Frazier said. Left untreated, a varroa mite infestation can wipe out a bee colony within a few months.
SOURCES AND RELATED WEB SITES