Independent Project Apivox
e-mail: glebskij@gmail.com
Abstract: The well-known
method of thermal action on Varroa mites has proven itself more or less
successfully only in thermal chambers. In apiaries, not a single design of a
hive or device for treating bees from Varroa mites has taken due to its low
efficiency, labor intensity and cost. The method of combating Varroa mites in a
hive that we have developed is based on suppressing the development of the mite
population by regularly destroying eggs and nymphs of mites in the sealed brood
of bees. This method does not destroy adult female mites, but gradually reduces
the infestation of families by the gradual death of adult females under the
influence of temperatures and their own age, while significantly reducing the
arrival of a younger generation to replace them. The so-called depopulation
process occurs. The usage of Sunny Hive,
built to implement this method in practice, make possible a multiple reduction
in the chemical load on bees without worsening their condition and, ideally, is
capable of ensuring the maintenance of bee colonies without any treatment and,
at the same time, without significant damage of them by Varroa mites.
Keywords: mites, Varroa, hive, bees, diseases
The so-called "thermal" method of combating Varroa mites has
long been known and has found some application in bee-treatment thermal
chambers. However, due to its labor-intensive nature, it is rarely used.
Numerous attempts have been made to treat bees for mites directly in the hive.
Numerous patents exist on this topic, including CA2916599A1, EP2789227A1,
EP2915424A1, RU2296465C2, US5069651, US6475061B1, US9363984B2, US11122781B2,
and US11129370B1. However, the complexity and high cost of the equipment, as
well as the poorly thought-out nature of the technology, have meant that this
equipment has not been used for practical work in apiaries. What is the main
problem with this method and these patented devices? The problem is that they
all believed they could kill the Varroa mite females by heating the hive
interior to 38-43°C. This was their main mistake. Varroa females don't die at
such temperatures, but are more or less significantly weakening. Varroa mites
population's development, after a slight pause, continues after a while.
We turned to the research of Soviet scientists Akimov and Piletskaya, as
well as Muravskaya [1], [2], [3], [4], [5], who in the 1980s conducted crucial
studies proving that the most effective treatment can be applied to that
portion of the Varroa mite population that seemed most immune to the effects of
chemicals and natural acids—to the Varroa mites brood in sealed honey bees
brood cells.
Figure 1. Thermogram of Varroa mite egg
viability from Akimov and Piletskaya's paper "On the Viability of Varroa
Mite Eggs." The percentage of Varroa mite eggs that die under given
temperature and humidity conditions is indicated.
They showed that elevated temperatures, starting at 36°C (96°F) in the
bee nest, significantly inhibit the development of mites brood. At temperatures
above 37°C (97°F), almost complete mortality of Varroa mite eggs and nymphs is
observed, while at 43°C (113°F), partial mortality of the females themselves in
brood cells is observed (Fig. 1). Moreover, the greatest impact is on mites in
drone brood, which is known to be a powerful accelerator of mite population
growth, especially during the pre-swarming period.
However, what works flawlessly in the laboratory works quite different
in reality. A single high-temperature treatment of the combs does not
completely kill the mites in the combs and some mites remain on the bees and
also survive. All of them reenter the next brood and quietly make up for lost
time. The effectiveness of such a method is low.
This leads to the solution: the temperature effect on young Varroa mites
must be achieved through a combination of three factors: the most effective
temperature, the optimal duration of a single exposure, and the mandatory
periodicity of exposure during the active season of bees life. It was the
attempt to combine these three factors that led to the birth of our new hive -
- Apivox Sunny Hive. Testing continued for apprximately six years, and the hive
design is now close to optimal (Fig. 2). In the 2025 season, a temperature
logger was installed in the latest modification of the hive, providing us with
a continuous stream of data on the temperature in the bees' nest between the
brood frames. At the end of March was performed the first alcohol wash of
Varroa mites from worker bees.
Figure 2. Experimental apiary consisting of
prototypes of the Solar Hive and the latest models. The objective is to study
temperature regimes inside the hives under various weather conditions, as well
as the response of bees to temperature effects of varying levels.
April results: with air temperatures ranging from +20C to 23°C,
temperatures in the bee nest ranged from +36C to +38°C. Temperatures in the
hive were not so high and had a depressing rather than lethal effect on the
mites brood (Fig. 3).
Figure 3. Temperature achievements in April
2025.
In May, sunshine and air temperatures between +26C and 28°C allowed nest
temperatures to reach +38-39°C for a week. Under these conditions, most of the
Varroa mites eggs and deutonymphs in the bees brood should have to die (Fig.
4).
Figure 4. Temperature achievements of the end
of May 2025.
It should be noted that no negative impact of high temperatures in the
nest on the brood or queens was observed. The brood did not die, and the queens
continued laying eggs.
June was very cold and rainy. The June honey flow was virtually lost.
There was no significant impact on the mites. In early July, an intermediate
mites wash was conducted on worker bees.
July saw periods of very high temperatures (32-33°C), sometimes reaching
36°C in the afternoon. During this period, as an experiment, we left the hive
body and heating element uncovered to determine the temperature range of the
interior of the hive containing combs. Monitoring showed that the air in the
center of the nest heated up to 46°C (Fig. 5), and the combs apparently even
more so, especially those located closer to the sunny side of the hive. There,
the combs melted and sometimes collapsed, indicating temperatures of around
50-60°C. The queens stopped laying eggs due to the dry air, and in some
single-hull hives, they died. However, surprisingly, the bees laid queen cells,
indicating that the young brood survived.
Figure 5. Temperature achievements at the
beginning of July 2025.
In conditions of high outdoor temperatures, it is necessary to give the
bees a break from the heat inside the hive. This will prevent a decrease in the
queen's egg production and even partial death of the brood. An experiment
monitoring the temperature in the Sunny Hive with the body and heater shields
closed and an outside temperature of 28-30°C (82-86°F) and partly cloudy skies
showed that the temperature in the nests of all colonies was around 34-35°C
(94-95°F). At the same outside temperature and full sun, the temperature in the
nest reached 38°C (Fig. 6).
 |
Figure 6. Temperature experiments at the end of
July and beginning of August 2025
Thus, for 3-4 hours, the hive temperature was maintained in the range of
+37-38°C, which provides a moderate effect on the young mites while causing
minimal harm to the bees. Under this same regime, with outdoor temperatures of
+30°C or higher, the hive temperature would remain at +40-43°C.
The results showed that if temperatures do not exceed +40-41°C, even
prolonged exposure, up to a week, it does not harm the brood or queens. Colony
development is not impaired. Temperatures above +40°C (i.e., +42-43°C) can be
used, but it is best to limit the exposure to one day, repeating the exposure
every 2-3 days to allow the brood and queen to rest from overheating. If the
hive temperature can then drop to +39-40°C, the exposure can be continued for
another 1-2 days. However, after this, the colony should also be given a rest
period. If stable sunny weather with outdoor temperatures of +35-40°C is
expected, in addition to installing standard shields, the hives should be given
substantial shade. This can be achieved by using either a shared shelter or
individual sun-reflecting covers.
Bee colony mite infestation was controlled by alkaline washes using a
3-5% solution of sodium hydroxide. The results were quite good (Fig. 7). It
should be noted that these colonies were used in the apiary as usual, producing
offshoots and commercial honey.
 |
Figure 7. Graphs of actual mite infestation
(solid line) and theoretical calculated value (dashed line) with a doubling of
Varroa mites population per month.
The results are as follows:
1. With an estimated mite population growth rate of 64 times per season
from late March to early October, the increase in mite infestation in the
experimental hives was 3.5-4.5 times, which is 14-18 times less! Meanwhile, the
colony in the standard hive showed a 4.1-fold increase in mite infestation only
from August to September, i.e., over one month.
2. Taking into account one fall treatment with bipin (amitraz), which is
quite sufficient, the fall24/fall25 ratios range from 0.9 to 2.5 in new
2025-model hives, and up to 4.3 in 2024-model hives.
3. Taking into account one fall treatment with bipin (amitraz), in some
colonies the fall24/fall25 ratio is less than one, indicating a negative trend.
4. It's clear that the final mite infestation level in a colony depends
on its initial level in spring. Therefore, one fall treatment is highly
recommended, if not mandatory. This will allow the colonies to safely survive
the winter and the entire following summer season without any more treatment.
Thus, it can be stated that Sunny Hive has everything necessary to
actively suppress the development of Varroa mites, especially in the moderate
climate.
References:
1. Влияние температуры на
откладку и развитие яиц Varroa
jacobsoni. Акимов И.А.,
Пилецкая И.В. Вестник зоологии 1985
2. О жизнеспособности клещей Варроа. Акимов И.А.,
Пилецкая И.В. Журнал Пчеловодство №8 1983
3. Особенности развития
клещей варроа в пчелином и трутневом расплоде. Пилецкая И.В. Вестник зоологии 1988
4. Влияние температуры и
влажности на клеща. Муравская А.И. Журнал Пчеловодство №8 1984
5. Биология клещей Варроа. Муравская А.И. Журнал
Пчеловодство №12 1979
1. The Effect of Temperature on the Laying and Development of Varroa
Jacobsoni Eggs. Akimov, I.A., Piletskaya, I.V., Bulletin of Zoology, 1985
2. On the Viability of Varroa Mites. Akimov, I.A., Piletskaya, I.V.,
Journal of Beekeeping, No. 8, 1983
3. Developmental Features of Varroa Mites in Bee and Drone Brood.
Piletskaya, I.V., Bulletin of Zoology, 1988
4. The Effect of Temperature and Humidity on the Mite. Muravskaya, A.I.,
Journal of Beekeeping, No. 8, 1984
5. Biology of Varroa Mites. Muravskaya, A.I., Journal of Beekeeping, No.
12, 1979
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