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Subject:
From:
"Malcolm (Tom) Sanford, Florida Extension Apiculturist" <[log in to unmask]>
Reply To:
Discussion of Bee Biology <[log in to unmask]>
Date:
Thu, 4 Mar 1993 09:44:00 EDT
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FILENAME:  MARAPIS.93
 
            Florida Extension Beekeeping Newsletter
    Apis--Apicultural Information and Issues (ISSN 0889-3764)
                 Volume 11, Number 3, March 1993
 
                VARROA MITES-A COMMUNITY PROBLEM?
 
     Many beekeepers are individualists.  Experience trying to get
beekeepers to act in unison reveals at best a laissez faire
attitude about cooperating together on certain projects.  In fact,
the history of associations and other groups dedicated to
beekeeping issues more often than not shows that beekeepers
actively work against each other.  Evidence from seminars and other
educational events also supports the thesis that beekeepers are
content to go about their business independent of their neighbors.
 
     To non beekeepers, the individuality of many beekeepers seems
strange, for honey bees are just the opposite.  They are the most
social of creatures.  A single individual in a beehive, be it
queen, drone or worker, means nothing.  Survival depends on working
together for the common good.  If this is a good strategy for bees,
then why do beekeepers not subscribe to it?
 
     In the past, the rugged individualistic beekeeper could
function well enough.  In fact, the craft demanded one be a self-
starter and an innovator.  Times were simpler (or seemed so) and
there were fewer non beekeepers with whick to interact.  Advances
in transportation and increases in growth and development have
affected rural and urban areas.  This has resulted in problems
often associated with activities of other people.  For the
beekeeper, this has meant everything from death of colonies because
of pesticide application to permanent loss of beehive locations.
 
     In 1987, Varroa mites were detected in the United States,
forever changing the face of beekeeping.  Fortunately for U.S.
beekeepers, a technology was in place to deal with the Varroa mite,
a parasite that effectively kills most honey bee colonies it
invades.  Certain chemical control methods were legal and labelled;
they reduce mite populations in beehives by over 95%.  It is
important to understand, however, that although chemicals control
the mite population, the threat is not eliminated and populations
can resurge dramatically.  In all probability, the beekeeping
community will have to deal with Varroa mites from now on.
 
     Although chemical control has blunted the effects of the mites
in individual bee colonies, it also allowed a myth to perpetuate
itself.  This is the belief that Varroa could be handled just like
other problems in beekeeping by the individual beekeeper whenever
and wherever it was deemed convenient and appropriate.  The
dynamics of Varroa-bee interactions, however, suggest something
different.
 
     It is now recognized that Varroa mites are not only a honey
bee community problem, they are a beekeeper community problem.
This idea was brought into focus by Marion Ellis, Nebraska State
Apiarist at the American Beekeeping Federation meeting in Kansas
City.  In his presentation, he referred to an article in the
December, 1991 issue of American Bee Journal entitled "How Varroa
Mites Spread," by Dr. Eva Rademacher (pp. 763-765).
 
     Through a series of experiments, Dr. Rademacher found that
Varroa mites rapidly spread among colonies in a beeyard.  The main
cause of growth of mite infestation is drifting parasitized bees,
not natural increase of mites within individual colonies.  The
conclusion: It is not the infestation of a single colony, but
rather the general rate of infestation for the entire yard that
should be monitored.
 
      Comparing two locations where infested apiaries were within
two kilometers (1.2 miles), Dr. Rademacher also showed re-
infestation rates to be dramatically different based on infestation
rates of nearby apiaries.  If the rate was 900 mites/colony or less
(low invasion pressure), re-infestation in apiaries in close
proximity was three times more than normally expected; if 900
mites/colony or more (high invasion pressure) were present, the
figure rose to 11 times normal.   Thus, according to Dr.
Rademacher, "...it is not 'hive mites' which endanger the colony,
but rather the 'immigrants.'"  Given this evidence, she suggests:
 
1.  Nuclei or natural swarms which have been treated for Varroa,
should be placed at locations where a low mite fluctuation from the
surroundings (low invasion pressure) can be expected.
 
2.  It is not helpful to treat just one or several of the colonies
in a beeyard because of the danger presented by other infested
colonies.
 
3.  Beekeepers with beeyards rather close to each other should make
arrangements to medicate their entire stock at the same time,
because of the invasion pressure which leads to a rapid increase of
mite population within only several weeks.
 
4.  Invasion pressure also plays an important role when colonies
are moved to other areas.  Not only will a beekeeper want to
determine the level of infestation in the new foraging area, but
the keeper in that area should also be concerned about the level of
infestation of incoming colonies.
 
5.  Natural swarms should be medicated before being incorporated in
the beeyard.
 
6.  It is also important to prevent robbing.  It has always been
accepted that the robbed colony suffers.  Now the robbing colony
itself can be the victim from by invading mites.
 
     The message is clear.  Effective Varroa control should be
undertaken as a beekeeper community effort.  If not, then presence
of nearby infested colonies will quickly undermine the money and
effort any beekeeper expends to control mite populations.
 
                       WHERE ARE THE BEES?
 
     A colleague who works in the Master Gardener Program asked me
the other day about the feasibility of establishing beehives in
urban areas.  Many home gardeners, it seems, are observing declines
in honey bee populations leading to reduced yields.  They are
asking where the bees are.
 
     I'm not sure why there might be fewer honey bees than before,
but in Florida, the Varroa mite is a good possibility.  It has now
been about five years since introduction of this parasite, more
than enough time to seriously weaken, if not kill outright, a
majority of unmanaged colonies.  Feral or wild bees no doubt
contributed greatly to home gardens as pollinators in the past.
However, these insects can no longer be taken for granted.  It
appears that a more "pro-active" pollination program is in order,
the purposeful placement of honey bee colonies in areas where
pollination appears to be limited.
 
     In educational parlance, another "teachable moment" is at
hand.  This concept arises from the idea that you can only educate
when you have a person's attention.  Now is the time, therefore, to
ensure that every home gardener knows how valuable and from where
his/her pollination comes from.  There are potential liability
problems in locating honey bee colonies in urban areas, but the
risks are minimal if certain precautions are taken.  An added
advantage over pollination potential is the fact that actively
managed colonies will provide competition for wild African bees
when they arrive.  Those associated with beekeeping should take
advantage of this opportunity, one borne out of the adversity of
Varroa mite predation.  There has never a better time to put honey
bees and beekeepers in their rightful place as valuable
contributors to the food supply.
 
                    CADA NEWSLETTER PUBLISHED
 
     I am in receipt of the second issue of the newsletter
published by the Caribbean Apicultural Development Association
(CADA).  At the recent meeting of the 5th International Conference
on Beekeeping in Tropical Countries, the first Board of Directors
was elected.  The President is Mr. Mohammed Hallim (Trinidad and
Tobago) and the Secretary is Dr. Daniel Pesante (Puerto Rico).
This issue of CADA newsletter contains an account of how the
Association helped re-establish honey trading between St. Lucia and
Martinique, and articles about Dr. Eva Crane, understanding
swarming in the subtropics, and why the Africanized honey bee is an
unwanted guest in the Caribbean.
 
     Now that CADA is getting off the ground, the Association is in
need of more members.  Anyone in the region, from Florida, the
Caribbean or the Latin American mainland (two mainlanders
[Venezuela; Surinam] are officers) should contact Dr. Pesante,
Animal Science Dept., P.O. Box 5000, College Station, Mayaguez, PR
00681, ph 809/265-3854, fax 809/265-0860.  The Association is also
soliciting memberships from those interested in participating in
CADA activities.  Dues of $15.00 per year should be sent to the
Treasurer:  Jorge Murillo Yepes, P.O. Box 612, St. Georges,
Grenada.
 
                       FACT SHEETS UPDATED
 
     Recently, I have been able to update and reprint some fact
sheets.  This series was previously known as "Hints for the Hive,"
but that concept has been abandoned in an effort to standardize
information developed in the Department of Entomology and
Nematology.  All fact sheets will now bear the designation ENY.
The new ones are:
 
ENY 101  Sources of Beekeeping Information
ENY 105  Florida Bears and Beekeeping
ENY 112  Extension Apicultural Visual Aids
ENY 114  Information on the African Honey Bee
ENY 115  Good Neighbor Guidelines and Ordinances
ENY 116  Chalkbrood Recommendations
ENY 120  Upward Ventilation
ENY 121  Wax Moth Control
ENY 125  Preserving Woodenware in Beekeeping Operations
ENY 126  The Value of Pollination by Honey Bees
ENY 127  The Varroa Bee Mite
 
     Of particular interest are numbers 114 and 127.  Now that the
African bee is getting some press and is about to enter New Mexico,
there is sure to be more demand for information on this
controversial insect.  The Varroa sheet now has pictures of Varroa
which compares its size to honey bees and also shows the organism
most likely to be confused with the mite, the bee louse (Braula
coeca).  All these are available in printed form from me, and are
slated to be on CD-ROM disks in county offices soon.
 
     Beyond the new numbers, of course, I continue to have on hand
a limited supply of the hint series.  These include:
 
HINT 102  Honey and Its Uses
HINT 103  Honey Adulteration
HINT 104  Florida Bee Inspection
HINT 106  Honey House Sanitation and the Florida Food Law
HINT 107  Florida Honey Labelling Regulations
HINT 108  Producing Section (Comb) Honey
HINT 109  How to Exhibit Honey
HINT 110  Sample Pollination Agreement
HINT 111  Solar Beeswax Rendering and Hints for Exhibiting Wax
          Blocks
HINT 113  Using Honey In Large-Quantity Recipes
HINT 117  Honey Marketing Survey
HINT 118  Producing Pollen
HINT 119  Financial Management for the Beekeeper
HINT 122  Bee Stings and Reactions
HINT 123  Extension Apiculture in Florida
HINT 124  Financial Statements and Ratios for Beekeeping Operations
HINT 128  Infant Botulism and Honey
HINT 129  Honey Judging and Standards
HINT 130  Moisture in Honey
 
                           MITE MEETING
 
     I am in receipt of a report generated by the Bee Mite Informal
Meeting held at the Entomological Society of America convention in
Baltimore, December 7, 1992.  It contains some interesting tidbits
that all may not be aware of.
 
     Surveys in Bee Culture indicated that tracheal mites were
reported in 30% of states in 1984, and this rose to 80% by 1987 and
100% by 1992.  Large losses were reported in northern areas where
bees were confined for long periods.  Treatments reported by bee
inspectors in 1992 were:  51% of beekeepers not treating; 37%
treating with menthol crystals; 21% using grease patties and the
rest using illegal treatments.  Tracheal mites did not appear to
affect honey production, but did result in decline in number of
beekeepers.  Although tracheal mites have been known for 100 years,
there is no information on what they are actually doing to
colonies.  Major suspicions are they pass on viruses and bacteria
which do the actual damage to colonies.
 
     Varroa has been found to be involved with organisms called
spiroplasms.  These can be found in nectar and have been implicated
in large-scale dieoffs.  In bees infected with spiroplasms, all
Varroa associated with them also have spiroplasms.
 
     A good many experiments are being carried on with oils and
other substances to control populations of both mites.  These
include hot corn oil, garlic oil, thymol, cinnamon oil, Listerine
(R), which contains menthol, and even salad dressing (oil plus
vinegar).  Questions that need to be addressed continue to be:
finding resistance mechanisms, determining sampling technology,
developing life tables for mites, and figuring out what bees are
doing with oil and grease placed in colonies.
                          TAKING PRIDE
 
     The National Honey Board's PRIDE program is off and running.
You can now get a two-color decal for your truck, van, shop or
production facility.  It's free when you send for the PRIDE
education kit.  The purpose of this program is to support safe
beekeeping and honey handling.  This will add to honey's already
sound reputation as a pure and natural product.  For more
information, contact the Board, 421 21st Ave., Longmont, CO 80501-
1421, ph 303/776-2337.
 
 
Sincerely,
 
 
 
Malcolm T. Sanford
Bldg 970, Box 110620
University of Florida
Gainesville, FL 32611-0620
Phone (904) 392-1801, Ext. 143
FAX: 904-392-0190
BITNET Address: MTS@IFASGNV
INTERNET Address: [log in to unmask]

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