FILENAME:  JUNAPIS.91
 
 
Florida Extension Beekeeping Newsletter
Apis--Apicultural Information and Issues (ISSN 0889-3764)
Volume 9, Number 6, June 1991
 
                      TRACHEAL MITE ENIGMA
 
     There are a good many beekeepers and scientists scratching
their heads about tracheal mites.  Nobody seems to be able to
reconcile why high mite levels last fall did not necessarily
translate into large colony losses this spring.  Informal reports
from California to Michigan reveal this quandary.  Dr. Roger
Hoopingarner in his last B-Plus, the beekeeping report from
Michigan State University, summed it up:
     "I still have not figured out the tracheal mite...A year ago
one of the colonies that survived the winter was headed by a
daughter queen from the Lonesome Hive (a colony Dr. Hoopingarner
keeps in his yard).  It had a tracheal mite level of about 80% at
that time.  It still has the same queen this year, and yet the
tracheal mite levels have dropped from 33 to 45% in the two samples
that we have examined this winter.  At the inspection yesterday
(April 18, 1991), I had to divide the colony since it had five hive
bodies (3/4 depth supers) full of bees.  They were starting queen
cells!"
     Other pieces of evidence add to the confusion.  It seems that
researchers in the Rio Grande Valley of Texas, where the first
detection of Acarapis woodi occurred in 1984, are unable to keep
mite levels high enough to do effective research on the critter.
Early studies in Florida were also plagued with very large
variation in mite populations that confounded investigators.  Some
California beekeepers had high mite levels in their colonies last
fall and were expecting the worst, but in contrast to previous
years' experience, most hives came through the winter with flying
colors.  Beekeepers in Florida's panhandle have not experienced
losses similar to those in 1986-1988, which many attributed to
tracheal mites.  Some colonies in Florida have traditionally had
high mite infestations, but never suffered the devastation visited
on those in the panhandle.
     All this is not surprising considering the tracheal mite
literature and its subsequent introduction into the United States.
It may be instructive, therefore, to review the history of this
controversial parasite.
     Great losses of bee colonies on the Isle of Wight in the
British Isles during the years 1901-1905 were correlated with the
eventual discovery of the Tracheal mite, Acarapis woodi, by Dr. J.
Rennie in 1919.  Dr. Leslie Bailey, a renowned authority on bee
diseases, called the "Isle of Wight Disease," presumably caused by
the tracheal mite, a myth (L. Bailey, "The 'Isle of Wight Disease':
The Origin and Significance of the Myth," Bee World, Vol. 45, pp.
32-37, 1964).  Dr. Bailey said a primary reason for the notoriety
of "Isle of Wight Disease" was sensationalized press releases which
caught beekeepers' attention.  His observations on the issue
include:
1.  Major symptoms described, such as bees with distended abdomens
or crawlers, are indicative of many kinds of diseases, including
nosema.  Prior to discovery of the mite, nosema was in fact
diagnosed as the problem.  Crawlers were often not as infested with
mites as were normal individuals.
2.  The disease correlated with a time of disastrous winter
weather; there were at the same time no losses in other beekeeping
areas from mites.
3.   The assumption that all parasites cause "serious damage" is
not valid.  Although tracheal mites shorten infested bees' lives,
according to Dr. Bailey, it is only by a "relative amount."
     Dr. Bailey's conclusion was that the mite was a scapegoat for
large colony losses.  He also stated that beekeepers did not
understand the disastrous effects of their own actions including
experimental treatments, moving bees and especially transferring
bees from skeps to moveable-frame hives.  Finally, he said that
beekeepers were not aware of all possibilities and were searching
for specific answers to a complex problem.  After detection in the
United States, Dr. Bailey stuck to his guns and predicted the mite
would not be a problem here.
     There is another side to the tracheal mite issue.  Brother
Adam, a monk at Buckfast Abbey, disagreed with Dr. Bailey's ideas
on "Isle of Wight Disease." (B. Adam, "'Isle of Wight' or Acarine
Disease:  Its Historical and Practical Aspects," Bee World, Vol.
49, pp. 6-18, 1968).  He concluded that it was a new disease and
the spread was very rapid since many incidences were reported on
the British Isles when infested bees were moved in.  Weather
factors were not contributive; honey flows were better than
average; nor were beekeeping practices at fault.  With reference to
the latter, Brother Adam said, a transition period from skeps to
moveable-frame hives did occur, but beekeepers did not lack skills
or experience.   In addition, symptoms of nosema disease, Brother
Adam said, were different than those found in "Isle of Wight
disease."  They were more like "disappearing disease" and the queen
was usually not affected, which is the case in nosema.
      When the tracheal mite (Acarapis woodi) was first detected in
the United States, several hundred bee colonies were destroyed by
Animal Plant Health Inspection Service (APHIS) in an effort to
control the mites; however, this policy was soon abandoned.
Whether or not tracheal mites were a "problem" for beekeepers took
on many of the same dimensions as described above for "Isle of
Wight Disease."  Six years after its introduction, the arguments
continue.
     This brings us back to Brother Adam.  His answer to tracheal
mites has been breeding resistant bees.  He reported the mites
reached Buckfast Abbey in 1915, when crawling bees were seen and
even though all colonies produced excellent spring clover and
heather crops, some 30 died that winter.  Only Italian bees
survived; all British bees died.  The surviving stock became the
nucleus of the Abbey's breeding program.
     A recent article in the Wall Street Journal touts Brother
Adam's work in developing resistant bees, calling his Buckfast
queen, the "Breakthrough Bee Bred by a British Monk."  According to
the article, the U.S. Department of Agriculture brought in 15
Buckfast queens; one died enroute, but the remaining 14 survived a
six-month quarantine on a Louisiana island.  They are now being
propagated on a large scale; it is hoped the descendants will
produce disease resistant colonies in areas of the U.S.
     As Brother Adam concludes, according to the article,
"Americans have always taken the health of their bees for granted.
Now they must pull up their socks--or lose their colonies."
Presumably this means using his "disease resistant" stock.
Unfortunately, the tenor of the article is more journalistic jargon
than anything else.  There is no mention of controversy surrounding
either introduction of the stock itself or the methods used by
Brother Adam to determine resistance.  Nor is his long-standing
debate with Dr. Bailey referred to.  The fact remains that, like
many beekeeping issues, the tracheal mite story is too long to fit
in a prescribed number of column inches in any newspaper.
     Several major gaps in our knowledge lead one to be skeptical
about experiments with and claims for tracheal mite resistance.
The mite's life cycle is not fully understood; nor is its
population dynamics in a bee colony.  There are no recommended mite
thresholds above which it is suggested to treat colonies.  The one
material currently registered for treatment is tricky to apply and
thus, its reliability is always in question.  Research on tracheal
mites is confounded by a lack of statistically valid sampling
procedures and the problem that detection is destructive of bees
and the required dissections are extremely labor intensive.
     Perhaps the biggest unknown is how the tracheal mite actually
damages a bee colony.  According to the article mentioned above,
mites "...clog the breathing tubes of bees,...leaving millions of
honey bees gasping for breath."  This scenario is possible
considering the packed condition of many heavily infested tracheae.
However, holes are also punctured through the tracheae and
hemolymph is probably sucked up by mites. Secondary infections of
fungus or virus are always possible.  Finally, it is almost
impossible to isolate the effects of tracheal mites on a colony,
especially when other ailments (foulbrood, chalkbrood, nosema)
might also be present.  Until much of the above information is
known, the tracheal mite enigma will continue.
     The tracheal mite situation parallels many disease and pest
situations in beekeeping which appear to ebb and flow through the
years.  For example, I now have reports of an extreme chalkbrood
epidemic in Israel and the Brazilian-Argentinean border continues
to be affected with an outbreak of American foulbrood.  It seems
that beekeepers are not immune from situations that plague other
agriculturalists.  Prevailing environmental conditions will favor
certain disease or pest problems each year in ways that are often
not predictable.  It's the kind of thing that causes beekeepers,
and in spite of Brother Adam's protests to the contrary as reported
in the Wall Street Journal, bee scientists, to have sleepless
nights.
 
                        DISEASE DIAGNOSIS
 
     A new booklet has just been published by the USDA's
Agricultural Research Service.  It is Agriculture Handbook 690,
written by Drs. H. Shimanuki and D. Knox and entitled:  Diagnosis
of Honey Bee Diseases.  The purpose of the publication is to
acquaint readers with laboratory techniques used to diagnose
diseases and detect and identify parasites, pests, and other
abnormalities of the honey bee.
     The handbook accomplishes its objective very well.  Several
methods of detection for brood diseases are described and
accompanied with helpful line drawing.  A table of comparative
symptoms for American and European foulbrood, sacbrood and
chalkbrood is also included.
     Adult diseases pests, parasites and predators are also
described in some detail in the publication.  Nine methods are
shown to detect tracheal mites.  Diagnosis of both Varroa jacobsoni
and Tropilaelaps clareae are detailed.  Finally, there is a section
on Africanized honey bees and pesticide poisoning.
     Although the information is excellent in the 57-page booklet,
getting a copy looks to be a potential headache.  Inside the cover
it states that copies are available from the National Technical
Information Service, 5285 Port Royal Rd., Springfield, VA 22161.
However, phone calls (703/321-85470) to the service have resulted
in the agency not being able to find the publication.  A problem
appears to be that the handbook is so new (April, 1991) that it is
not yet in the system.  Maybe by the time this newsletter gets to
you, the publication will be ready for sale to the public.
 
                      APIMONDIA MEETING ON
 
     In spite of the troubles in Yugoslavia, the organizing
committee has decided to go ahead with the 33rd International
Congress of Apiculture (Apimondia).  It will meet in Split
September 29 through October 4, 1991.  I have copy of the "First
Circular" which advertises the event as well as other materials.
If you wish any of this information, give me a call.
     The Congress promises to be an exciting one.  Its general
theme is "Apis mellifera carnica from Anton Jansa Onwards."
Yugoslavia is the home of the Carniolan or Gray bee.  The country
has a long and distinguished beekeeping history.  Perhaps the most
famous Yugoslavian apiculturalist was the pioneer, Anton Jansa
(1734-1773), and the Congress has his likeness as its official
insignia.
     The registration fee is $220 and should be sent to the General
Secretary of Apimondia, Corso Vittorio Emanuele 101, 1-00186, Rome,
Italy.  Tel 6-6512286 or FAX 6-6548578.  Other information on the
beekeeping expo, contests and hotel accomodations should be
addressed to the National Organizing Committee, C/O UNIONDALMACIJA,
Congress Dept., Prilaz XXVI, Dalmatinske Divizije 4, Post Box 385,
YU-58000 Split, Yugoslavia.
 
                 NATIONAL HONEY BOARD REFERENDUM
 
     The long-awaited referendum on the Research, Promotion and
Consumer Information Order for honey will be held this August,
according to the U.S. Department of Agriculture's Agricultural
Marketing Service.  The referendum period will be August 1 through
August 31, 1991.  All ballots must be postmarked by August 31 and
received by September 6.  Two questions will be on the ballot:
Question No. 1:  Do you favor a continuation of the Research,
Promotion and Consumer Information Order for Honey?
     A "YES" vote on question No. 1 means you are in favor of the
continuation of the order.  A "NO" votes means you are opposed to
its continuation.
Question No. 2:  Do you favor termination of the refund of
assessment provisions of the Research, Promotion and Consumer
Information Order for Honey?
     A "YES" vote on question No. 2 means you are in favor of the
termination of the refund provision.  A "NO" vote means you are
opposed to the termination of the refund of assessments.
     Both questions will be tabulated independently.  Voters should
respond to both questions.  Questions left unanswered will not be
counted.  Eligibility to vote is limited to any person who produced
or imported honey into the U.S. duirng the period January 1, 1990
through December 31,1990 and who is now a producer or importer of
honey.  For further information on eligibility, contact your local
ASCS Office.
 
                      BEEKEEPERS INSTITUTE
 
     You should soon be receiving the information brochure
concerning the Beekeepers Institute to be held at 4-Camp Ocala,
August 23-25. 1991.  This year's event will concentrate on
information concerning mites (tracheal and Varroa) and the African
honey bee which has now been detected in the U.S.  The first
official stinging incident by these bees was recently recorded in
Texas.  Fortunately, it was a fairly minor event, but portends of
what is to come.
     If you have not received the Institute brochure by the last
part of July, please give me a call.  Deadline for late
registration, for which there is a hefty fee, is August 9, 1991.
 
Sincerely,
 
 
 
 
Malcolm T. Sanford
0740 IFAS, Bldg 970
University of Florida
Gainesville, FL 32611-0740
Phone (904) 392-1801, Ext. 143
FAX: 904-392-0190
BITNET Address: MTS@IFASGNV
INTERNET Address: [log in to unmask]