Subject: ARS NEWS --New Control for AFB?

From: [email-masked] (Adam Finkelstein)
Date: Mon, 18 Apr 1994 12:16:17 GMT

BEE FUNGUS LEADS TO NEW CONTROL FOR HONEY BEE DISEASES
 
Contact:  Dr. Hachiro Shimanuki, Bee Research Laboratory,
Beltsville Agricultural Research Center, Agricultural Research
Service, USDA, Beltsville, MD, (301) 504-8205.
 
Dr. Hachiro Shimanuki never thought that one honey bee disease
would lead to a cure for another.  But that's what U.S.
Department of Agriculture scientists discovered by surprise
last year.
 
"It was serendipitous, to say the least," said Dr. Shimanuki
of USDA's Agricultural Research Service.  "We were looking for
a natural control for two serious bacterial diseases--and it
came from a fungus that causes another, less serious bee
disease."
 
The natural remedy--a substance found in some crops--is also
produced by the Ascosphaera apis fungus that causes honey bee
chalkbrood disease, which infects larvae inside the bee hive. 
The scientists are filing a patent application on the
discovery.
 
In laboratory tests, the substance inhibited the growth of the
two bacteria that cause European and American foulbrood
diseases, the scientists found.  They also said it poses no
harm to the bees and would not harm humans.
 
The surprise discovery didn't happen overnight, but only after
more than a decade of research on New Jersey honey bees showed
a curious trend in honey bee diseases.
 
>From the early 1960s to 1988, scientists at the agency's Bee
Research Laboratory in Beltsville were studying ways to
control European foulbrood in southern New Jersey.  The
disease was widespread in areas where honey bees were used to
pollinate blueberries and cranberries. 
 
During that time, Dr. Shimanuki said, researchers also
discovered an increase in chalkbrood, which by 1983 had become
widespread in southern New Jersey.
 
But samples of diseased bees analyzed at our lab showed that,
during 1980 to 1990, European foulbrood in bees from New
Jersey declined drastically and was hard to find by the late
1980s," he said.  "Meanwhile, chalkbrood remained constant in
bees from that region."
 
Further tests confirmed that the A. Apis fungus produced a
substance that inhibited both types of foulbrood.  ARS
entomologist Dr. Mark F. Feldlaufer, of the Insect
Neurobiology and Hormone Lab in Beltsville, later isolated and
purified the substance.  William R. Lusby, a chemist at that
lab, identified it.
 
"Both foulbrood diseases are found in all 50 states.  Both
infect honey bee larvae inside the hive and can kill the bees
if left unchecked," Dr. Shimanuki said.  The bacterium
Melissococcus pluton causes European foulbrood; Bacillus
larvae causes American foulbrood.
 
"American foulbrood is considered the biggest disease threat
to U.S. honey bees, causing an estimated $8 million in damage
each year," he said.  "Losses from European foulbrood and
chalkbrood are unknown.  In some states, regulations require
beekeepers to destroy colonies infected with the diseases."

Currently in the United States, only the antibiotic
oxytetracycline is approved by the U.S. Food and Drug
Administration for controlling European and American
foulbrood.  "We are concerned that these diseases could
eventually develop resistance to the antibiotic, so we need
new, natural biological controls,"  Dr. Shimanuki said.
 
The substance discovered by Shimanuki and colleagues could be
fed to bees either as part of a sugar-water syrup or could be
placed in hives in patties along with pollen and other feed
supplements.
 
"A new natural control for foulbrood diseases would help
ensure an adequate supply of honey bees for pollination of
important agricultural crops," he said.   Nationwide, the
value of honey bee pollination ranges from $1.6 to $5.7
billion a year, according to a recent study by State
University of New York (SUNY) researchers.
 
Each year, U.S. farmers rent about 1 million bee colonies each
year to pollinate a variety of crops such as almonds, apples,
alfalfa, apricots, oranges, grapefruits, melons, cucumbers,
asparagus and broccoli, according to USDA estimates. 
According to the SUNY study, about 400 agricultural crops
worldwide, including 130 in the United States, are pollinated,
at least partly, by honey bees.
 
The ARS research team includes Dr. Shimanuki, agency
entomologist David A. Knox of the bee lab, Dr. Feldlaufer and
Lusby.
 
May 1993                 --By Sean Adams, USDA-ARS, (301) 344-2723
                                     [email-masked]
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Adam Finkelstein  VDACS Apiary Inspector 116 Reservoir St Harrisonburg VA 22801
703-433-1006 (V)   703-434-5607 (Fax)   703-564-4394 (Pager)
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