Lexington, Kentucky
May 9, 2007
By Aimee Nielson
Fact: Commercial migratory beekeepers in North America are
suffering significant hive losses for a variety of reasons.
Fiction: The losses are not caused by cell phones, cell phone
towers or cannibalistic bees, and the decline does not spell the
end of civilization within four years, said
Kentucky State University
Apiarist Tom Webster. Fact: a honeybee decline will impact
agriculture. Fiction: the impact will not wipe out agriculture.
“When we have a tough problem that is difficult to solve and
takes time to solve, it seems to create an information void,”
Webster said. “People feel a need to start filling in that void,
and all sorts of unfounded ideas start going around. We will see
an impact from this decline; some commercial beekeepers have
lost 90 percent of their hives. But, we do need to remember that
honeybees are not native to North America and civilizations
existed before the honeybee arrived.”
Webster believes that to understand what’s causing the honeybee
decline, rumors and unfounded stories have to be put aside so
facts can be the focus. Most beekeepers in Kentucky maintain a
small number of hives and most of those are for honey
production. Overall the state has around 5,000 colonies
responsible for about 250,000 pounds of honey, according to the
Kentucky Agricultural Statistics and Annual Report for
2005-2006.
Kentucky Department of Agriculture’s State Apiarist Phil Craft
said, before concluding that the deadouts (hives where bees have
died) in Kentucky are due to a new disease or malady, it’s
important to examine why beekeepers lose colonies in the winter.
Kentucky’s beekeepers begin preparing their hives for winter as
early at July of each year.
“There are three considerations that we keep in mind in helping
a colony of honeybees get through the winter,” he said. “Bees
must have sufficient food stores in the hive. In Kentucky that
means a hive needs about 50 to 60 pounds of honey for the bees
to feed on during the winter.”
Craft said a second consideration is that the minimum, late-fall
population required for a hive to make it through winter is
about 25,000 to 30,000 bees.
“By spring, the number in the hive will be greatly reduced, and
there is a natural decrease as older bees die,” he continued.
“The bees cluster together and consume honey to keep warm when
the temperature is below 55 degrees - the colder the outside
temperature, the tighter the cluster. I always say that as the
number of bees in a hive decreases, the hive may reach critical
cluster size, below which the survival of the bees is unlikely.”
Craft said even in a disease- and pest-free colony of bees with
sufficient food and plenty of bees to cluster, half won’t
survive until spring – only bees that develop in late fall will
live that long.
“The third consideration is healthy bees,” he said. “Honeybees
that have been weakened by mites or disease will die even
sooner. If you don’t monitor and control mites and disease, you
can’t tell whether bees are actually as healthy as they appear.”
The recent Easter freeze may also be a factor, as Craft noted
that periods of warm weather, followed by cold weather are hard
on bees. This situation happened in February and again in April.
“We often have these periods of warm and then cold and then warm
again in Kentucky. When it gets warm, bees become more active,
consume more honey and then they have to recluster during the
next cold snap,” Craft said. “The result is dead bees in
multiple small clusters. These days we consider a winter loss of
20 to 25 percent acceptable. Unfortunately it’s common to lose
one or two hives, which means that beekeepers with only a few
hives can lose all or most of their bees.”
Craft said beekeepers with larger numbers of hives usually make
plans in the spring to replace lost colonies by making divides
or purchasing package bees. Still, Craft said that these losses
are much lower than in feral, or wild, colonies where as much as
75 percent of first-year honeybee colonies fail to survive
winter.
“The difference between the high losses in nature and in our
managed colonies is good beekeeper management and good
preparation of hives in winter,” Craft said. “Unfortunately last
year’s honey flow made preparation especially difficult for
Kentucky beekeepers, and that’s why beekeepers who failed to
feed their bees heavily in the fall may find starved bees this
spring.”
So aside from normal winter losses, complicated by poor honey
flow and the topsy-turvy, hot-cold pattern of late winter and
early spring, what is causing the above average population
decline?
Webster and Craft agree that the reasons for the decline are
many and haven’t completely been determined. Colony Collapse
Disorder may explain some losses that were not winter losses and
which have occurred during periods when bees were still raising
brood.
“This phenomenon, called CCD for short, has received a lot of
media attention,” Craft said. “While earlier reports said only
migratory beekeepers with large operations were affected, some
smaller keepers have reported losses as well – some as great as
50 percent. Losses from CCD are now being reported in about 25
states, but CCD may or may not have been a real factor in all of
these cases.”
Craft said that reports from some large beekeeping operations in
Georgia, which provide a lot of package bees to Kentucky every
spring, state that Georgia hives are thriving.
“I believe that losses reported here in Kentucky seem to be more
related to starvation and poor condition of bees than to CCD,”
Craft said.
Webster said that several pathogens and pests, some of which are
familiar to Kentucky beekeepers, could be a factor in the
decline. He believes nutrition could play a part as well.
“For example, if all the plants other than the crop to be
pollinated have been treated with an herbicide, that could be
hurting the bee population,” he said. “It’s akin to living off
of only grilled-cheese sandwiches. What I’m trying to say is
bees need a variety of nutrition sources.”
Some national attention recently has been paid to the finding of
a new species closely related to a disease that has long-plagued
U.S. beekeepers – Nosema apis. Webster confirmed that this new
species of Nosema has been found in hives in Florida, Kentucky
and several other states. A laboratory diagnosis is the only way
to determine Nosema’s presence.
University of Kentucky College of Agriculture Horticulture
Specialist John Strang said the honeybee decline could impact
fruit and vegetable crops.
“We’d most likely harvest fewer cantaloupes, watermelons,
cucumbers, pumpkins and squash, which would be smaller and could
be misshapen,” Strang said. “Some fruit trees might not set as
much fruit without honeybees, but it’s not going to wipe us out.
The recent Easter Freeze was much more devastating to our
growers than the bee situation.”
Strang emphasized that other pollinators help the honeybees out.
“We have a lot of native bees and bumblebees that do a great job
pollinating,” he said. “We haven’t always had honeybees to do
the work, but we depend on honeybees to do a lot of pollination
in a short period of time, when we have a large number of crop
flowers to pollinate.”
So what can beekeepers do to protect their hives? Webster said
to avoid putting hives near places where agricultural chemicals
are heavily used; give bees diverse food sources; keep
well-known parasites under control and, for unexplained
problems, send small bee samples to the KSU lab for analysis.
Craft said one of the healthiest things beekeepers can do for
their hives is to cull older brood comb. He believes it’s one of
the best things beekeepers can do to promote a healthy
environment in their hives. He also recommended treating all
hives with the antibiotic fumalgillin because the new strain of
Nosema, as well as the old strain, responds well to treatment.
“This antibiotic is available from all beekeeping supply
companies,” Craft added. “Add one teaspoon of fumalgillin to
each of the first two gallons of sugar syrup fed to each
colony.”
Beekeepers interested in sending small bee samples to Webster’s
lab at KSU should first contact him to make sure they collect
the sample in a way that will provide the most accurate results.
Webster can be reached at 502-597-6351 or via e-mail at
Thomas.webster@kysu.edu.
UK College of Agriculture, through its land-grant mission,
reaches across the commonwealth with teaching, research and
extension to enhance the lives of Kentuckians. |
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