Bee Mites And Mineral Oil
by: Dr. Pedro P. Rodriguez
I wish to apologize for the delay in publication of details of my work
on this subject.
The reasons are unintentional and compelling. There were many questions
that I felt needed to be answered (some of which I am still pursuing) and
because I suffer from double vision (from a bout with hyperthyroidism)
that induces severe headaches after periods of field work, reading, use
of word processor and other tasks that require eye strain. Although the
project is incomplete, I feel that my findings are significant and valuable
to beekeepers who may wish to implement them. Also, my findings may be
valuable to other investigators who may wish to perform related work on
this subject. Hence release of present findings is considered appro-priate
at this stage. (Technical language and statistical data has been carefully
limited).
Background:
Born and raised on a farm, I was initiated with animal husbandry chores
as a very young child. I started caring for sick animals by smuggling them
into pens heavily crowded by my "patients." I still recall my parentsí
admonitions for "wasting" time and money on "worthless" causes, especially
my motherís for using her castor oil to treat leg mites on chickens and
ear mites on rabbits. My experience with mineral oil continued when as
a young veterinarian I used mineral oil for treating ear mites on cats.
Later in my career, mineral oil became part of my professional "tool bag"
when as a government supervisor of food plants, I approved the use of food
grade mineral oil for maintenance of food preparation equipment. I observed
the first Varroa mites in 1983 while working with honey bees in Spain.
From that date, I became fascinated with the ability of the little creatures
for attacking honey bee colonies and eventually destroying them. >At the
time, Fulvex was the chemical of choice in Europe for treatment and cure
of bee mites. I suspected mites would eventually develop re-sistance to
Fulvex as most often happens with chemicals used for disease control, fact
that was later corroborated by other investigators (Faucon et al, 1955;
Lodesani et al, 1955; Smodgen et al, 1955). The potential need for a different
agent to treat bee mites in case the mites develop resistance, led me to
wonder if my "oil treatment of old" would be as effective for the treatment
of bee mites. While pondering about this possibility, many other questions
arose in my mind.
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would mineral oil affect honey bees?
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mode, quantity and frequency of application of the oil.
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would the oil affect bee larvae or the egg laying ability of the queen?
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could the oil be applied all year long or be limited to seasons?
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what would be the mechanism of action of the oil?
From my previous experience, I knew that oil kills mites. I became intrigued
with the idea of finding the answer to this puzzling question and started
researching literature on mite biology, anatomy, physiology and other factors
that could lead to the answer deriving the following data.
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the body of the bee mites is flat, thus having a high ratio of surface
volume (factor also used by Italian researchers of bee mites as expressed
on a recent post to Bee-L), charac- teristic that make bee mites vulnerable
to treatment with oils.
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mites, like honey bees, breathe through spiracles. The bee/mite body size
differential ratio may be utilized to attack the mites with oil without
harming the bees.
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mites utilize body pores for diffusion of gases and for moisture intake
(Gary et al, 1989; Gary et al 1991b; Pugh et al 1992). A study with female
mites has demonstrated that mites control gaseous exchange through adjustment
of components of their respiratory system (Pugh, PJA; King, PE; Fordy MR
Na: Experimental and Applied Acarology, Vol. 15, No. 2, pp 123-139, 1992).
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mites have a short life cycle (12 days for tracheal mites and 18 days for
Varroa mites) and are most vulnerable to treatment during their ectoparasitic
phase.
After eleven years of consecutive loses of bee colonies to mites and the
economic impact that these parasites were having on apiculture worldwide,
it was obvious that it was imperative to find an effective treatment for
the parasites. Realizing that after continued treatment of my colonies
with Apistan strips, mites continued to proliferate and that colony health
and size were diminishing, I determined that a vigorous form of treatment
had to be implemented.
On 1 April 1996, I applied Apistan strips (three strips per colony)
between frames in the brood chambers. After six weeks of treatment with
Apistan, four colonies had perished and mites continued to proliferate
in all remaining colonies. Based on my knowledge of success- ful treatment
of mites on domestic animals, treatment was switched from Apistan to mineral
oil. All the Apistan strips were removed (after waiting two weeks to allow
Apistan to wear off) before starting use of mineral oil in an effort to
eliminate the possibility of cross effect between the two agents. Treatment
with food grade mineral oil was initiated on 1 June 1996 on twenty colonies
while five colonies (randomly selected) were used as controls.
Rationale:
Mineral oil is effective in the treatment of mites on domestic animals.
Food grade mineral oil is approved for use in food processing plants in
the United States because it is not toxic and because it does not contaminate
food products. Hence, mineral oil, if effective against bee mites, could
be utilized for the treatment of bee mites during the entire year contrary
to other acaricides that have seasonal limitations. The two species of
bee mites existing in the United States (Acarapis woodi and Varroa jacobsoni)
spend some of their life span on the surface of their host bee. Because
of the known house keeping and grooming habits of the honey bee, it was
reasoned that bees would "transfer" oil from their legs to the rest of
their body and to other parts of the colony if they came in contact with
oil. Food grade mineral oil does not contaminate honey or honey bee products
and is not toxic to honey bees, provided that the oil is not applied in
excessive quantities (see description of different methods of application
employed). Twelve consecutive months of work with oil have revealed amazing
(positive) results in the treatment and control of bee mites.
Method:
A. Laboratory work:
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Mineral oil was applied with the tip of a prove directly to mites seen
on bees. Close observation revealed that mites would drop off the bees
(time was not measured).
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Live mites were carefully collected from various colonies, placed in open
glass jars and brought home. Some mites were treated with oil directly
in the jars, others were carefully removed (to prevent physical harm) and
placed on a glass surface coated with a film of mineral oil, or, on waxed
paper or seran wrap coated with a film of mineral oil. Some mites were
allowed to remain untreated in the glass jars, surviving for several days.
Mites exposed to oil were observed to become motionless almost immediately,
however, some remained active (lethal doses or lethal times were not evaluated)
for some time.
B. Field work:
Several methods of application of the mineral oil have been tested
in a period of time spanning 51 weeks, (1 June 1996 - 24 May 1996).
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Sheets of waxed paper or freezer paper were coated with a film of mineral
oil and placed on the bottom boards of the colonies. Dead mites were collected
and counted. Yields varied between ten in a small colony to 112 in a large
colony.
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Strips of waxed paper (10 inches long x 1 1/2 inches wide) were coated
with a film of mineral oil and placed between frames in the brood chambers.
The number of strips varied between six and ten depending upon the size
of the colonies. Coated strips of paper were replaced every two weeks while
this form of application lasted. .
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A continuous bead of mineral oil (up to 2.5 cc) spread on top bars of the
frames.
Evaluation of treatment:
Effect of the mineral oil treatment was measured by counting mites
by uncapping brood cells. Yields varied according to degree of infestation,
size of the colonies and length of treatment. Initial count yielded as
high as 54 infected cells per one hundred cells opened. Mite count varied
between one to three per cell. Mite count per hundred brood cells uncapped
dropped drastically (54 % in some colonies to four percent in others) as
oil treatment continued. It was acknowledged that the procedure was labor
intensive early in the process.
Other avenues of treatment were sought in order to make the procedure
cost effective to commercial operations dedicating special attention to
varying quantities of oil applied. The most successful method was determined
to be when oil was applied in a continuous bead along the surface of the
top bars.
At first, the amount of oil was measured and applied with a graduated
eye dropper (available to any beekeeper), arriving at 2.5 cc of oil as
a safe quantity (before the bees became soaked in oil). At present, oil
is applied from a bottle (similar to a honey bear) with a spout with an
opening of 1/16" diameter. Oil is applied steadily, along the top bars
leaving a continuous line of oil measuring approximately the size of a
thin noodle. In the beginning of the operation, it was thought that the
oil should be sprayed on the bars or spread by hand. In the course of the
applications it was determined that it is not necessary to spread the oil,
the bees spread the oil as soon as they walk on it.
I have now designed a board (from bakelite) that blocks the bees inside
the brood chamber while the oil is applied. The board is fitted with slits
that coincide with the top bars allowing application of the oil while perfectly
barring the bees inside to prevent stinging and applying the oil directly
to the bees.
Observations:
After 51 weeks utilizing food grade mineral oil in various ways the
following observations have been made:
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Food grade mineral oil can be utilized effectively to control bee mites
(acaricide) with quantities ranging from a mere film applied on waxed paper
and up to 2.5 cc applied on the top bars of the frames.
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Mite count per hundred capped cells examined diminished drastically, (54
% to 4 %).
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Appplication of mineral oil in the form described above has not affected
the queenís laying ability.
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All five colonies utilized as controls perished. (Test colonies were distributed
in three sites at least ten miles apart and each site had control colonies).
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Of the twenty colonies utilized for treatment with mineral oil: One absconded;
two were small and died due to pilferage. Seventeen remaining colonies
are thriving and building very large populations. Two colonies have two
brood chambers and eight honey suppers each. Two colonies have two brood
chambers and six honey suppers each.
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Control colonies perished quickly due to a combination of factors: Parasitized
bees became weak and abandoned their house keeping habits. Stores were
quickly robbed. Queens stopped laying and the bees died fighting the robbers,
from disease and lack of food. Nosema was observed in two of the heavily
parasitized colonies.
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The use of sheets of waxed paper smeared with oil and placed on the bottom
boards was abandoned promptly because these were observed to become covered
with debris thus reducing the effectiveness of the oil. Waxed paper or
other impervious type paper placed on the bottom boards while treatment
is taking place maybe valuable if used for the purpose of collecting and
counting dead mites.
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Capped cell exams revealed mites within drone cells as well as in worker
bee cells.
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Worker bee samples were collected, dissected and examined for tracheal
mites. No tracheal mites were found during the test period.
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Mineral oil was applied continuously every two weeks during the test period
including the winter months. The use of mineral oil did not affect egg
laying of the queens nor the health of the developing larvae. While it
may seem that oil applications should be made more frequently (judging
by the presence of mites after 51 weeks of treatment) economics tend to
indicate that more frequent applications might be prohibitive. This remains
as one of my questions still under study.
Conclusion:
Contrasted to the characteristics of other oils, lard, Apistan or menthol
(used as acaricides), mineral oil seems to offer a preferable medium based
on per unit cost, physical characteristics (odorless, flavorless, does
not deteriorate, does not contaminate honey or bee products, can be utilized
all year long) for utilization as an acaricide.
Posted to BEE-L on Sat, 12 Jul 1997 5
MINERAL OIL FOR BEE MITES TREATMENT PHASE II Tuesday, August 26, 1997
Mineral Oil for Bee Mites Treatment: Phase II
Method of Application of Mineral Oil
By: Dr. Pedro P. Rodriguez
On Sunday, August 24, 1997, a new method of application of mineral
for the treatment of bee mites was initiated in twenty four (24) colonies
previously treated with mineral oil as described in the file posted to
Bee-L
as E:\infinet\mineral oil for bee mites treatment. This method of application
continues the use of food grade mineral oil now denominated as white mineral
oil. Mineral oil is bottled into pint bottles, which have been previously
prepared as follows.
Materials:
ï pint bottles
ï bottle cap drilled with a 1/8th (*) inch bit in center of cap. (*)
this measurement has been changed to 1/16th inch to lessen the amount of
oil dispensed.
ï 1-1/2" x 1-1/2" x 1 inch piece of Douglas fir wood, drilled in center
with a 1-1/4 inch hole; a 1/4 inch slit is cut onto this, opening the previously
drilled hole on one side.
ï Tobacco pipe cleaning wire (serves as a wick).
ï 5" x 1-1/2" x 1/4 inch pieces of Luan wood (base of stand for bottle)
ï 1-1/2" x 1-1/2 x 1/4 inch pieces of Luan wood (creates bee space
under stand).
ï White mineral oil to fill bottles.
Description: (See Diagram: Mineral Oil for Bee Mites Treatment Phase
II)
Staple 1-l/2" x 1-1/2" x 1 inch drilled piece of wood on one surface
of the 5" x 1-1/2" x 1/4 inch piece of Luan wood and the 1-1/2" x 1-1/2"
x 1/4 inch piece of Luan wood under the other side of the 5 inch board
directly below the 1-1/2 inch drilled piece of Douglas fir wood (effectively
creating a "bee space"). The combination of these wood pieces makes an
effective stand for the oil bottle and a platform for the bees to walk.
Place two staples evenly distributed on the upper surface of the 5
inch piece of Luan wood creating loops to weave the tobacco pipe cleaning
wire through the loops.
Run one end of the tobacco pipe cleaner through the hole on the bottle
cap and bend the end of the wire inside the cap. Fill bottle with white
mineral oil and replace cap.
Place full bottle (cap down) with the tobacco pipe cleaning wire on
the hole of the previously assembled pieces of wood described above and
weave the wire through the two staple loops on the 5 inch piece of Luan
wood.
The pint bottle serves as a dispenser for the oil that will flow through
the tobacco pipe cleaning wire (serves the function of a wick).
This bottle can be placed on the landing platform of the hive. Or it
can be inserted into the lower brood chamber in the same way as are feeding
bottles. For my testing period, I removed one frame and placed the bottle
in its stand over the top bars of the first brood chamber to prevent spilling
by predators and diluting by rain. Bees were observed to be in contact
with the oil as they walked on the surface of the stand or under it through
the bee space.
Advantages of this method:
Bees are not exposed to excessive amounts of oil; hence there are no
dead bees due to soaking. Follow up inspection has revealed a maximum of
three dead bees on one board. A single operator can apply thousands of
dispensers in one day, hence making the system applicable for commercial
beekeepers. Dispensers are easily manufactured and can be standardized
and produced in large volumes. No need for utilization of costly foggers.
A. Foggers are expensive (not suitable for hobbyists).
B. Eliminates a wet environment (from fog) inside colony and around
the cluster during winter months.
C. Eliminates possibility of explosions of oil fog when exposed to
butane flames or other types of combustible mixtures.
D. Apparatus reduces handling and application time, hence becoming
cost effective for small operators and commercial beekeepers. Cost per
unit is minimal and effect is long lasting.
E. Ingredients remain non-contaminating to the colony, bee products
and environment. Mechanism dispenses a smaller quantity of mineral oil
than previously used, hence reducing the inherent fears of the oil being
found in honey.
©.1997.Dr. Pedro P. Rodriguez - All Rights Reserved.
dronebee@norfolk.infi.net
Reproduction for personal and non-profit use only.