Colony Collapse Disorder: Dr. Diana Cox-Foster
As beekeepers harvest honey and make preparations for the winter, researchers continue to investigate why as many as a quarter of the nation’s commercial beekeepers have lost up to 90 percent of their honey bee colonies to the mysterious ailment known as Colony Collapse Disorder.
But at least now, there’s reason for hope. A research group led by Diana Cox-Foster, professor of entomology in Penn State’s College of Agricultural Sciences, has identified a recently discovered pathogen, Israeli Acute Paralysis Virus (IAPV), the presence of which is strongly correlated with hives suffering from the disorder. The research results were reported in the journal Science.
“We have not proven a causal relationship between any infectious agent and CCD,” the researchers reported. But their findings “indicate that IAPV is a significant marker for CCD.”
Colony Collapse Disorder first was reported to the college’s Department of Entomology in November 2006 by migratory beekeeper David Hackenberg from the Lewisburg area. Penn State researchers and extension educators soon teamed with government agencies, other universities, and the bee industry in a CSI-style race to identify the causes and come up with solutions.
At stake is more than just honey; many important U.S. crops rely on pollination services provided by commercial beekeepers, including apples, almonds, peaches, soybeans, pears, pumpkins, cucumbers, cherries, raspberries, blackberries, and strawberries. Nationwide, honey bee pollination is worth about $15 billion to the food supply and is credited with helping to produce a third of the nation’s diet. “In addition to agricultural crops, honey bees also pollinate many native plants in the ecosystem,” Cox-Foster told federal legislators at a March congressional hearing addressing the CCD problem.
Hives suffering from CCD exhibit several unique symptoms: The colony rapidly proceeds from a strong colony with many individuals to a colony with few or no surviving bees; queens are found with a few young adult bees, lots of brood (developing offspring), and more-than-adequate food reserves; and no dead adult bees are found in or near the colony. In other words, most of the bees simply disappear.
To identify pathogens that might be causing or contributing to CCD, the researchers sequenced all the genetic material found in bees from healthy and affected colonies. “The genome of the honey bee had just been completed,” says Cox-Foster, “so it was possible to do the sequencing and then eliminate the genetic material of the bees.”
Besides the honey bee genetic material, DNA was found from a number of viruses, bacteria and fungi. While most of those organisms were found in healthy and CCD colonies, IAPV was found only in colonies suffering from CCD.
Scientists believe that other stresses, such as parasitic mites and pesticides, may play a role in CCD by compromising bees’ immune systems, making them more vulnerable to pathogens such as IAPV. Researchers next will try to infect bees with IAPV to see if they can induce colony collapse and determine what other factors are involved in the disorder.
Link: http://www.sciencemag.org/cgi/content/abstract/sci;318/5848/283
Link: http://live.psu.edu/story/25747
Link: http://www.aginfo.psu.edu/psa/07SumFall/honeybees.html
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