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Florida Extension Beekeeping Newsletter
Apis--Apicultural Information and Issues (ISSN 0889-3764)
Volume 13, Number 6, June 1995
Copyright (c) 1995 M.T. Sanford "All Rights Reserved"
VARROA MITE POPULATION DYNAMICS
As we learn more about Varroa jacobsoni in honey bee hives,
the dynamics between mite and bee populations become more complex.
Several things are thought to contribute to mite population
buildup, including the natural rate of increase in the bee colony
based on the amount of brood and the number of mites being
introduced from nearby infested colonies. This latter factor is
thought to be extremely significant in "reinfestation" of treated
colonies (see March 1993 APIS). Another consideration is the
switch by Varroa mites in the fall from the decreasing number drone
brood, which they seem to prefer, to worker brood (See October 1994
APIS).
There are many examples of populations that are "density
dependent" in the biological world. These groups cannot expand
indefinitely because as their number increases, conditions change
to slow, and in some cases stop, further growth. Often this
"negative feedback loop" is a response to dwindling food resources.
A study published in Journal of Apicultural Research (Vol.
33(3):155-159, 1994) by M. Eguaras, J. Marcangeli and N. Fernandez
shows that this is also true for Varroa. As the mite population in
a bee colony increases, there is a reduction in the number of
Varroa offspring. Even the addition of one mite the authors deem
significant.
Theoretically, a honey bee colony treated in the fall,
provided it survives the winter, comes into spring with a low
Varroa mite population ready to rapidly expand. A honey bee colony
in good condition can usually outpace the mite population buildup
during the more active season. Nevertheless, it is extremely
important to know the population level of Varroa mites in a bee
colony in case chemical control becomes necessary.
Ideally, bee colonies should be chemically treated only when
there is an "excessive" quantity of mites determined by ether roll
or some other test. Unfortunately, what is considered "excessive"
is not known. It is subjective, depending on the observer's point
of view, and can vary greatly with the testing procedure. The
results of the above study now complicate this situation more by
suggesting that this all-important number is also influenced by the
mite population level itself. The level at which treatment is
necessary, therefore, like many other aspects of Varroa control,
becomes a moving target (see August 1994 APIS).
The negative feedback loop in the Varroa population makes
biological sense. It keeps parasitization to a "reasonable" level
and prolongs the survival of the bee colony, lengthening the time
the mite population has to feed on its host. Unfortunately, this
does little for the beekeeper. Any level of parasitic activity
inevitably decreases surplus production in a colony, the
apiculturist's bread and butter. And the authors of the above
study say that this mechanism alone cannot keep bee colonies alive.
This is particularly true in winter, when many highly infested
brood cells are present and a non-equilibrium between host and
parasite leads to colony death. The study concludes: "Thus,
beekeepers must still apply chemical products to maintain low mite
populations."
BACKGROUNDER FOR HONEY LEGISLATION
"The U.S. Congress will soon consider new farm legislation to
replace the expiring Food, Agriculture, Conservation and Trade Act
of 1990." This is the first sentence in the foreword to
Agricultural Economic Report Number 708, Honey: Background for
1995 Farm Legislation, USDA, April 1995, by Frederic L. Hoff. The
document contains a wealth of historical information and analysis
on the beekeeping industry and is a fine supplement to AER 680, The
U.S. Beekeeping Industry, May 1994 (see July 1994 APIS). Besides
a summary of changes in the honey price support system from the
1960s to 1994, it discusses the structure of the beekeeping
industry, effects of the honey program on all levels of U.S.
society and current policy issues. This publication is mandatory
reading for anyone who might have an interest in how the honey
industry fares as part of the 1995 farm bill.
In general, this report shows a historical downward trend in
colony numbers, beekeepers and profit margins. Some of the salient
points are summarized below:
In 1947, there were 5.9 million hives in the United States.
There was a steady decline until 1973. From then until 1986,
colony count leveled off at about 4.1 million. A precipitous drop
followed, with hives declining 16 percent since 1989 to the present
level of 2.9 million. During the same period, the number of
beekeepers has also declined, although exact figures are not known.
Honey production mirrored colony numbers to some degree,
declining from 272 million pounds in 1952 to 150 million pounds in
1985. The average production in the 1950s and 1960s was 240
million pounds, dropping to 209 million during the 1970s and 1980s.
As beekeeping operations have increased in size, production per
colony has been higher, averaging 66 pounds per colony since 1986.
Outfits of less than five hives were dropped from production
figures in the 1986, inflating this average. The value of honey
production has increased over the years. It averaged $42.3 million
from 1945-1971. Since then, it went to a height of $141.5 million
in 1979, then dropped to $121-$125 million from 1991-1993.
In spite of the general rise in overall production, honey
prices have remained relatively low, declining from a record high
of $0.61 per pound in 1981 to $0.54 in 1993. The report only
covers up to 1993 and, therefore, does not reflect current prices,
driven even lower by a recent flood of imports. A decline in honey
program payments from $100 million in 1988 to $16 million in 1993,
along with an increase in operational expenses over 15 percent has
also hit beekeepers hard.
Most beekeepers supply pollination free as a byproduct of
their honey-producing activities. About a million colonies are
estimated to be involved in commercial pollination. Fees range
from $9.50 per colony to as high as $35. Using an average figure
of $20, the estimated value of purchased pollination services is
$40.7 million in 1988. This value is estimated to increase in the
future.
The report concludes: "The fate of the honey price support
program will likely be determined by the 1995 farm bill." It lists
several options Congress might consider:
1. Extend Provisions of the Existing Honey Program: This would
force producers to depend more on honey sales and commercial
pollination for most of their income. However, it would also
provide some income protection in a sluggish and weak honey market.
2. Adopt and Extend Provision of Government Reform and Savings
Act: This program would make loans, but eliminate subsidies.
Although not providing beekeepers with income because loans are
repayable with interest, it could be a source of working capital.
3. Protect Program With Import Quotas: Controlling imports using
import quotas or tariff-rate quotas would eliminate beekeeper
dependence on the honey program for income. This is highly
unlikely given the prevalent "free trading" philosophy.
A full copy of the report can be requested by dialing 1-800-
999-6779. The cost is $9 and includes postage for U.S. residents
(others add 25 percent to the cost). Visa and MasterCard are
accepted. I reiterate what I said last July, "The beekeeping
community now has plenty of ammunition to back up its arguments for
public support in many arenas. However, the time and expense to
produce this document will go for naught, if those in the
beekeeping industry do not use the information to its fullest
potential."
Deliberations about the 1995 farm bill will likely be
determined by the U.S. Department of Agriculture (USDA) budget,
according to the Farm Bureau as reported in The Speedy Bee, May
1995. The historical downward trend in help to beekeepers is also
mirrored in the rest of agriculture. Current USDA reorganization
is expected to eliminate more than 1,200 field offices, terminate
more than 11,000 employees and consolidate 43 agencies into 29.
"With 4 percent of the federal budget set aside for USDA,
assumptions have been made that the $63 billion is doled out
directly to farmers," the article says. However, in reality less
than one percent actually goes to farm-only programs. The majority
(59 percent) was for food and nutrition assistance, while two
percent was absorbed in international food aid. The Commodity
Credit Corporation received 17 percent, while research, Forest
Service and Farm Service Agency received 3, 7 and 7 percent
respectively. The House and Senate have put all agriculture
programs on the table. Both are expected to debate the agriculture
budget in May or June, with a reconciliation agreement likely. The
bottom line: farmers must contact their representatives with their
concerns for both the 1996 agriculture budget and 1995 farm bill or
see continued erosion in support at the federal level.
THE NATIONAL HONEY BOARD READIES FOR THE 21st CENTURY
According to the National Honey Board Chairman, Mr. Neil
Miller, the Board is now working to be ready for the 21st century.
His letter in the latest National Honey Board News discusses
efforts "preparing to meet the challenges of promoting honey in a
changing environment." As part of this, Mr. Miller says, the board
is working on an international honey research database accessible
across the Internet and helping other countries promote honey to
their own consumers.
The development of the PackTrack computer program is another
example of the Board's commitment to tomorrow's (really today's)
business climate. The software provides a consistent way to
maintain a complete history of all honey purchases and to track
sweet processed for sale. It also will manage an accurate, up-to-
date list of contacts, including honey producers, importers,
vendors and customers. The system can search for data eight
different ways and there is an online help facility and a
calculator available at "the touch of a key." PackTrack requires
a 386 IBM compatible processor, running DOS 3.3 or higher. It,
along with a complete user's manual, sells for $8.95.
The honey board newsletter is also packed with other kinds of
information, including a detailed article on small business
exemptions from nutrition labeling. For more specifics about honey
labeling, and for Florida in particular, see the August, October
and November 1994 issues of APIS. For more information on National
Honey Board programs, see the February ("Honey Board Evaluates
Itself") and March ("A Honey of a Bibliography") 1995 issues of
APIS.
If you don't get the National Honey Board's newsletter, write
or call (800-553-7162). Also be advised that the Office address
has recently changed to 390 Lashley, Longmont, CO 80501-6045.
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]
APIS on the World Wide Web--
http://gnv.ifas.ufl.edu/~entweb/apis/apis.htm
Copyright (c) M.T. Sanford 1995 "All Rights Reserved"
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