[Pollinator] Christian Science Monitor: What's Happening To The Bees?

Wed Apr 4 13:45:17 PDT 2007

http://www.cbsnews.com/stories/2007/04/04/national/main2646409.shtml

What's Happening To The Bees?

April 4, 2007

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(Christian Science Monitor) This article was written by Moises
Velasquez-Manoff. 

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Beekeeper James Doan first began finding empty hives last fall. Entire bee
colonies seemed to have up and vanished, leaving their honey behind. Noting
the unusually wet fall in Hamlin, N.Y., he blamed the weather. Unable to
forage in the rain, the bees probably starved, he reasoned. 

But when deserted hives began appearing daily, "we knew it was something
different," he says. Now, at the beginning of the 2007 pollination season,
more than half of his 4,300 hives are gone. "I'm just about ready to give
up," says Doan from his honeybee wintering site in Ft. Meade, Fla. "I'm not
sure I can survive." 

The cause of the die-offs has yet to be determined. Its effect on the food
supply may be significant. Longer-term, it may also force a rethinking of
some agricultural practices including our heavy reliance on human-managed
bees for pollination. 

Scientists call it "colony collapse disorder" (CCD). First reported in
Florida last fall, the problem has since spread to 24 states. Commercial
beekeepers are reporting losses of between 50 and 90 percent, an
unprecedented amount even for an industry accustomed to die-offs. 

Many worry that what's shaping up to be a honeybee catastrophe will disrupt
the food supply. While staple crops like wheat and corn are pollinated by
wind, some 90 cultivated flowering crops - from almonds and apples to
cranberries and watermelons - rely heavily on honeybees trucked in for
pollinization. Honeybees pollinate every third bite of food ingested by
Americans, says a Cornell study. Bees help generate some $14 billion in
produce. 

Research is only beginning and hard data is still lacking, but beekeepers
suspect everything from a new virus or parasite to pesticides and
genetically modified crops. Scientists have hastily established a CCD
working group at Pennsylvania State University. Last week, the U.S. House of
Representatives' Committee on Agriculture held hearings on the missing bees.

For many entomologists, the bee crisis is a wake-up call. By relying on a
single species for pollination, U.S. agriculture has put itself in a
precarious position, they say. A resilient agricultural system requires
diverse pollinators. This speaks to a larger conservation issue. Some
evidence indicates a decline in the estimated 4,500 potential alternate
pollinators - native species of butterflies, wasps. and other bees. The
blame for that sits squarely on human activity - habitat loss, pesticide
use, and imported disease - but much of this could be offset by different
land-use practices. 

Moving away from monoculture, say scientists, and having something always
flowering within bee-distance, would help natural pollinators. This would
make crops less dependent on trucked-in bees, which have proved to be
vulnerable to die-offs. 

The stress on honeybees grew as native and wild pollinators diminished and
farmers came to rely more on honeybees. We've put "all of our pollination
eggs in the honeybee basket," says Mace Vaughan, conservation director of
the Xerces Society for Invertebrate Conservation in Portland, Ore. "We need
more baskets." 

An immune-system disorder? 

Meanwhile, beekeepers are seeing hives empty in a matter of weeks, sometimes
days. The entire adult bee population vanishes, except for a few juveniles.
This makes CCD difficult to study. "You have a crime scene, you know a crime
happened here, but you don't really have evidence," says Medhat Nasr,
provincial apiculturalist in Alberta, Canada. Eerily, the stored honey in
the hive remains untouched. Raiding bees from nearby colonies never
materialize, as is common. 

Records of suddenly empty hives go back as far as the late 1800s, but never
on this scale. Beekeepers dubbed it "autumn collapse," "spring dwindle," or
"disappearing disease." But Dennis vanEngelsdorp, the acting Penn State
apiarist, calls this manifestation the AIDS of bees. The remaining juvenile
bees appear to be rife with disease. To him, "It's clear that there is an
immune suppression," he says. 

What might suppress a bee's immune system is anyone's guess. But many
ascribe to a tipping-point theory: A variety of factors may have accumulated
until a single straw finally broke the bee's back. 

A review of honeybee history shows many suspects. The Varroa mite, native to
Asia, came to North America in the late 1980s. Since then, yearly losses of
between 15 and 20 percent have become the norm. "Before the mites, you could
be a bee-have-er," says vanEngelsdorp. "Now you have to be a bee-keep-er." 

Beekeepers are the first to acknowledge the stress of migratory pollination.
Carted on flatbed trucks from wintering sites in the South, the bees
crisscross the continent, first to California's almond groves, which rely
entirely on honeybees for pollination, and then northward throughout the
country, following the spring flowering season. Farmers have come to rely
increasingly on honeybee services, says May Berenbaum, head of the
department of entomology at the University of Illinois, Urbana-Champaign.
"Given its economic importance, beekeeping really hasn't gotten the
attention it deserves," she says. 

Poor nutrition may be another factor, says Vaughan. To prepare them for
winter, bees are fed high-fructose corn syrup and protein supplements. In
the fields they've pollinated, meanwhile, more often than not they've
gathered only one kind of pollen. Maybe, like other animals, they need a
diverse diet, he says. "If you only ate McDonald's every day, you'd be just
like that guy in 'Super Size Me,' " he says. "And he didn't feel that good."

Others, like Doan, suspect pesticides. 

Similar problem in 1990s France 

In the 1990s, France experienced a precipitous honeybee decline from "mad
bee disease." Honey production dropped by nearly one-third, to 25,000 tons.
French beekeepers blamed a newly introduced pesticide marketed under the
name Gaucho. From the same family as nicotine, the chemical targeted aphids'
navigational systems. And when the honeybees weren't finding their way home,
either, French beekeepers protested. The French government banned the
product in 1999. Though subsequent studies haven't found a strong link, bee
populations still haven't rebounded to previous levels. 

Others point to genetically modified crops - specifically, those with a gene
for a bacterial toxin called Bt. Initial studies indicated that it didn't
affect bees. But some beekeepers argue the trials didn't last long enough to
determine the long-term effects. (Doan says the same about the nicotinelike
pesticides.) A German study supports this. Scientists at the University of
Jena found that while Bt food had no direct effect on bees, when fed to bee
populations infected with parasites, they quickly became diseased. Alone, Bt
may do nothing. But in the presence of a parasite, it may facilitate
infection. 

"Maybe these toxins weaken the immune system," says John McDonald, a retired
biologist and hobby apiculturalist in Spring Mills, Pa., who wrote an
editorial on the topic for the San Francisco Chronicle 

But the shrinking of our so-called "pollination portfolio" is of more
concern to many entomologists than a die-off in commercial beehives. A 2006
National Academy of Sciences report declared that there was "direct evidence
for decline of some pollinator species in North America" - species
responsible for pollinating three-quarters of flowering plants. Europeans
have documented a parallel decline in their natural pollinators for years. 

On the U.S. East Coast, where a more ecologically diverse farming landscape
enhances species diversity, studies have shown that wild pollinators were
doing about 90 percent of the pollinating anyway, says Neal Williams, an
assistant professor of biology at Bryn Mawr College in Pennsylvania. "It
seems a little bit silly from a whole-country perspective, even from a
farmer perspective, that we would place so much emphasis on one species. We
don't do that with any other part of the economy," he says. 

Meanwhile, a Canadian study suggests that if canola farmers leave 30 percent
of their land fallow, they will increase their yields. Wild land provides
habitat for native pollinators, improving pollination and increasing the
number of seeds. "If we cultivate all the land, we lose ecosystem services
like pollination," says Lora Morandin, lead author on the study. "Healthy,
sustainable agricultural systems need to include natural land." 

Jennifer Tsang
Coevolution Institute <http://coevolution.org> 
423 Washington St. 5th Fl.
San Francisco, CA 94111-2339
T: 415.362.1137

F: 415.362.3070

www.nappc.org

www.pollinator.org

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