Abstract: Tropilaelaps mites are currently one of the most important enemies of bees, destroying large apiaries in a few months. Effective control of them, based on knowledge of the characteristics of their life and reproduction, can lead to the suppression of the uncontrolled development of the Tropilaelaps mite population in honey bee families. Meta-analysis of works of scientists around the world over the past 70 years, and our own studies of the impact on the Varroa mite population through regular destruction of their brood in sealed combs using such a parameter as elevated temperature, led to the understanding that there is a real possibility of suppressing the development of the Tropilaelaps mite population due to the temperature effect on the brood and these mites. The concealment of mites from all types of treatments in brood cells becomes in this case a factor of the success of the fight against them. The experiment allowed not only to confirm the effectiveness of temperature effects on the brood of Tropilaelaps mites to suppress the development of their population as a whole, but also to confirm that the Apivox Sunny Hive is capable of creating conditions for the gradual elimination of the Tropilaelaps mite population in the bee colony living in such a hive, and the widespread use of this type of hive is capable of clearing apiaries and entire regions of Tropilaelaps mites despite the presence of wild bees and apiaries in the vicinity infected with Varroa and Tropilaelaps mites.
Keywords: mites, Tropilaelaps, hive, bees, diseases
Introduction
Tropilaelaps mites, which have now become the second most powerful threat to beekeeping in southern Europe, have long been known in the countries of Southeast and Central Asia. Its homeland is the same as the homeland of the Varroa mite, and of the bees themselves - in Southeast Asia. Its development cycle in bee families is also well known to scientists. [1] (Fig. 1)
 |
Figure 1 Homeland of Tropilaelaps mites and its
development cycle in the bee colony |
The list of
scientific papers on this topic is constantly updated, in which studies are
conducted on the ability of mites to survive in conditions where there is no
brood suitable for feeding, that is, in open brood on eggs, on pupae and on
adult bees [2], [3]. The results that scientists obtain, in general, have been
known since the 70s of the last century - mites do not survive on adult bees
for more than 2-3 to 10 days. They survive on pupae partially, and do not
survive more than 2-3 days on bee eggs. They also cannot feed on them. These
seemingly very promising results concentrate the attention of one part of
scientists, creating a certain euphoria of the possibility of an easy victory.
In reality, they do not give a practical effect. None of the practicing
beekeepers, for whom beekeeping is a business, will leave the apiary without
brood for 21 days necessary for its complete cleansing. Moreover, there is
always someone nearby who did nothing, and whose apiary becomes a source of new
infestation, making all efforts useless.
Understanding
this, another part of scientists is focused on testing the possibility of using
chemicals used to combat Varroa mites, to combat Tropilaelaps mites [4].
Different methods are being tested, but in general the results are about the
same. The preparations kill the mites when they move around the honeycombs, and
are not effective if the mites are in sealed cells. Hence, various attempts to
create methods for combating Tropilaelaps mites appear. But, judging by the
results that have taken place all over the world, no method rids bee colonies
of Tropilaelaps mites with a sufficient degree of reliability. The mites
quickly make up for the lag. If up to 5 females can emerge from a cell when
infected with Varroa mites, then up to 14 females can emerge from a cell when
infected with Tropilaelaps mites. And this is a fact verified by scientists.
Thus, they reproduce almost three times faster than Varroa mites, and are much
less noticeable. Therefore, if a beekeeper notices them, the bee colony is
already close to collapse.
So, let's
see where Tropilaelaps mites are common today and where they may appear in the
near future according to scientists and try to understand the reasons for such
a picture [1]. (Fig. 2) First of all, these are the zones of Southeast Asia,
China, and partially the countries of Central Asia, in particular, Pakistan and
India. There is information about the spread of mites in the south of Russia -
in the Krasnodar and Stavropol Territories [5], as well as in Georgia [6]. In
all cases, the scale of bee losses is colossal.
Figure 2 - Potential areas of honey bee
infestation by Tropilaelaps mites
The figure
clearly shows which zones scientists have designated as potentially dangerous -
these are warm and humid zones where bees do not stop breeding process. In cold
regions of Europe, Asia, and South and North America, there is a winter
broodless period that mites are unable to survive. Moreover, this happens in
all apiaries at the same time. The same thing happens in too hot and dry
regions of Africa, Asia, Australia, and Europe, where brood is absent during
the hottest time of the year. Can we say on this basis that high temperatures
not only affect the reduction of brood in bee colonies, but also the fertility
of the mites themselves? Scientists from Pakistan have suggested such a
possibility [7]. This can be said with certainty about the Varroa mite. Yes,
high temperatures suppress the development of mites, and this has been proven
by the Apivox project, not only by conducting a meta-analysis of scientific
papers over the past 70 years, but also by conducting their own experiments
with the developed hive design, which allows the theory to be transferred to
practice - to apiaries. The Sunny Hive which we developed has proven its
effectiveness in combating Varroa mites over three beekeeping seasons in
several apiaries.
All this
led us to believe that Tropilaelaps mite populations, like Varroa mites, would
be suppressed by the death of their brood and maybe the mites themselves in
sealed brood cells under the influence of elevated temperatures. This seemed
all the more likely to us because Tropilaelaps mites are physically more
"delicate" than Varroa mites, which are well-hidden in a thick
chitinous shell. However, to be completely certain, a full-scale experiment was
required.
Materials
and methods of the experiment
It was
decided to conduct the experiment using our methodology in Georgia, involving
Caucasian bees and Georgian apiveterinary specialists. The experiments were
conducted in two different locations under the supervision of bee disease
expert Nino Kipiani, DVM, a representative of the National Food Agency of
Georgia, and representatives of the Georgian Bee Preservation Association, the
F. Benton International Beekeeping Association. The choice of Georgia as the
starting point for the experiments was no accident—the country's beekeeping
industry suffers severely from a combined infestation of Varroa mites and a
relatively new pest to the region, the Tropilaelaps mite.
It was
decided to conduct three experiments with different objectives. The first
experiment was to determine whether temperatures of +40°C or higher would have
a negative impact on Tropilaelaps mites located outside worker bee brood cells,
i.e., simply on the comb. The second experiment was to demonstrate the effect
of the same temperature on Tropilaelaps mites and their brood inside sealed
worker bee brood cells. The third experiment was intended to yield a
statistically significant result if the second experiment was successful. To
avoid "waiting for nature's favor" and not wait for sunny days to
warm the Sunny Hive to the required temperature, a thermostatic chamber was
used. A Thermo ELECTRON CORPORATION device was used in the experiment.
The first
experiment was conducted at the Tbilisi State Veterinary Laboratory. A sample
of infected honeycombs was collected from an apiary consisting of four bee
colonies in Tbilisi, owned by beekeeper Vakhtang Kakhniashvili. The thermostat
was set to working condition by Tamar Tagilauri, chief specialist in animal
disease diagnostics at the Laboratory of Virology and Serology. The thermostat
control panel was set to 40°C. We thought the results would be what we
expected, so it was conducted only once. The honeycomb containing brood and Tropilaelaps
mites on the surface was sealed in a paper envelope and placed in the
thermostat for two hours. After two hours, the honeycomb was returned to the
laboratory, and the heating results were visually analyzed by specialists
(Figure 3).
 |
Figure 3. Placing honeycombs with brood
infested with Tropilaelaps mites in a heat chamber during the first experiment
and analysis of the condition of Tropilaelaps mites on the surface of the
honeycomb after heating in a thermostat at +40C. |
The second
experiment was conducted in Western Georgia, at the Zugdidi Veterinary
Laboratory. Larisa Chkadua, chief specialist at the Zugdidi State Veterinary
Laboratory, prepared the thermostat in working order. The thermostat control
panel was set to +42°C. The remaining thermostat settings were the same as in
the first experiment. A comb containing worker bee brood infested with
Tropilaelaps mites was heated for three hours. Afterward, the cells containing
the brood were quickly opened using heated wax and a piece of paper. The
contents of the cells were removed, and their condition was analyzed by
specialists (Fig. 4).
Figure 4. Opening a comb with Tropilaelaps
mite-infested worker bee brood removed from a thermostat and analysis of the
content of the brood cells.
It should
be noted that preliminary inspection of brood cells revealed the presence of
some dead larvae even before the experiment due to severe mite infestation. Up
to eight Tropilaelaps mites were found in such cells at any one time (Fig. 5).
 |
Figure 5 Tropilaelaps mites from cells with
infected worker bee larvae
The third
experiment was conducted using a heat chamber containing 46 frames of brood
infested with Tropilaelaps mites. The temperature in the chamber was maintained
at 42-44°C. The heating duration remained the same—three hours. After the
heating period was complete, the cells were opened and the dead mites were
shaken out of the combs onto paper.
Experimental
results
The
experiments fully met our expectations.
The first
experiment finished with a negative result. A temperature of +40°C did not harm
the Tropilaelaps or Varroa mites. Their motility was quite high, and no signs
of damage or weakening were observed in either mite species.
The second
experiment finished with a positive result. After warming, we found dead
Tropilaelaps mites of all types in all opened cells (Fig. 6).
 |
Figure 6. Dead Tropilaelaps mites, mature and
immature forms, from a cell with a worker bee pupa, removed after warming the
comb with brood for 3 hours at a temperature of +42C.
Moreover,
in cells with a complex infestation—in which both Tropilaelaps and Varroa mites
were present—all forms of Tropilaelaps mites were dead, and adult Varroa mites
were severely depressed and inactive, although not dead. Their numbers were so
numerous that it might have appeared as if they had fallen onto a sticky board.
In fact, after opening the cell caps of the brood comb with heated wax and
paper, a sheet of paper was placed on the table, and the frame with the removed
cell caps was struck against the table. All these Tropilaelaps mites fell dead
from the opened cells. And there were indeed a great many of them.
During the
experiment, after warming the comb, larvae were removed from the brood cells,
and most of them were dead. We wondered whether the Tropilaelaps mites might
have been dead before the experiment, as the larvae they were feeding on had
died. To answer this question, we left a second comb containing brood from the
same hive in the laboratory. We found that, as in the first comb, the larvae
died from exposure of the mass of mites. I would like to point out once again
that, this comb was not heated in a heat chamber. As a result, by opening
several cells containing dead larvae on the second comb every day, we found
several living Tropilaelaps mites in them. This continued for approximately 10
days. Therefore, it can be concluded that the death of the larvae was not the
cause of the Tropilaelaps mites' death from starvation. It is safe to say that
the death of the mites was caused by heating brood comb up to +42°C (107°F) for
three hours.
The third
experiment was completely identical to the second, and its results were
identical. All Tropilaelaps mites of all ages that fell from opened brood cells
were dead. Temperatures during this experiment reached +44°C (113°F), but no
serious damage to the bee brood was observed.
Discussion
The first
experiment once again confirmed that temperatures around +40°C are not critical
for all mite species outside of brood cells. This is not news for Varroa mites,
which are known to die in heat chambers at temperatures above +50°C. However,
for Tropilaelaps mites, this is new, albeit negative, information. The
experimental results once again demonstrated that attempting to destroy mites
on combs or bees in a hive by heating the hive to moderate temperatures is
impossible. This also demonstrates why Tropilaelaps and Varroa mites do not die
in hot regions: because the temperatures in light-colored hives made of
sufficiently thick wood and located in the sun or shade do not reach
temperatures critical for mite brood in sealed combs, nor for foundresses on
combs or bees outside of brood cells, and sometimes even outside the hive on
clustered bees (Fig. 7).
 |
Figure 7. Experiments in the subtropical zone
near Islamabad. Integrated Pest Management Institute, National Agricultural
Research Centre, Pakistan
The second
experiment confirmed and even exceeded our expectations for suppressing
Tropilaelaps mite population growth by heating infested worker bee brood to
moderate temperatures, specifically 42-44°C, which is achievable in a hive with
a certain design, such as the Apivox Sunny Hive. The experiment demonstrated
that Tropilaelaps mites can be controlled directly in the honeybee nest by
overheating their brood in sealed comb cells. Furthermore, we believe this has
once again confirmed that temperatures higher than those typically found in the
nest, i.e., 33°C to 35°C, negatively impact both mite species and their brood.
It was somewhat surprising, but a pleasant surprise, to find that at these
temperatures, not only Tropilaelaps mite brood in the brood comb cells dies,
but also the foundresses themselves. This means that elevated temperatures have
an even greater impact on Tropilaelaps mites than on Varroa mites, as not only
does the rate of reproduction slow down due to the death of future generations,
but the foundresses themselves also die, and they will not begin a new stage of
reproduction when temperatures drop.
The results
we received also indicate that the effectiveness of Sunny Hive on Tropilaelaps mites will be
higher than on Varroa mites, on which it has a quite satisfactory effect,
significantly reducing the viability of their population in a honey bee colony.
Conclusion
The
following can be concluded from these experiments:
1.
Confirmation of the feasibility of active influencing on Tropilaelaps mites
population using elevated temperatures, without the use of any chemicals,
leading to a radical suppression, and even to complete elimination of it.
2.
Confirmation of the feasibility of using special heat chambers for one-time
heating of brood combs in apiaries with the goal of suppression of development
of Tropilaelaps mites population in bee colonies.
3. Confirmation of the feasibility of using
hives such as the Sunny Hive for the continuous suppression of Tropilaelaps and
Varroa mites populations present in bee colonies, as well as mites of both
species introduced by bees from outside apiaries affected by mite infestations.
This is a distinct advantage of the hive over heat chambers, as a single
treatment does not prevent the introduction of mites from neighboring apiaries
or the re-infestation by the mites of bee colonies.
References
1. Animal and plant health agency, The National
Bee Unit -National Agri-Food Innovation Campus
Sand
Hutton, York, YO41 1LZ Tropilaelaps
parasitic mites of honey bees
2. Ecology,
Life History, and Management of Tropilaelaps Mites Lilia I. de Guzman, Geoffrey R. Williams, Kitiphong
Khongphinitbunjong, and Panuwan Chantawannakul
3. Managing
the parasitic honey bee mite Tropilaelaps mercedesae through combined cultural
and chemical control methods Rogan Tokach, Bajaree Chuttong, Dan Aurell,
Lakkhika Panyaraksa & Geoffrey R. Williams
4. Denis L Anderson & John M K Roberts
(2013) Standard methods for Tropilaelaps mites research, Journal of Apicultural
Research, 52:4, 1-16, DOI: 10.3896/
IBRA.1.52.4.21
5. Тропилелапсоз –
инфестация медоносных пчел, особенности распространения в России Брандорф А.З.,
д.с.х.н., г.н.с., ФГБНУ ФАНЦ СЕВЕРО-ВОСТОКА СЕЛЕКЦИОННЫЙ ЦЕНТР ПО СРЕДНЕРУССКОЙ
ПОРОДЕ МЕДОНОСНЫХ ПЧЕЛ.
6. FIRST REPORT ON TROPILAELAPS MERCEDESAE
PRESENCE
IN GEORGIA:
THE MITE IS HEADING WESTWARD! Irakli Janashia1* ORCID: 0000-0002-4312-9133,
Aleksandar Uzunov2,3 ORCID: 0000-0003-1240-868X, Chao Chen2,3 ORCID:
0000-0002-9582-1105, Cecilia Costa4 ORCID: 0000-0001-9985-2729, Giovanni Cilia4
ORCID: 0000-0002-5234-1240 1- Institute of Entomology, Agricultural University
of Georgia, Tbilisi, Georgia 2 - State Key Laboratory of Resource Insects,
Institute of Apicultural Research, Chinese Academy of Agricultural Sciences,
Beijing, China, 3 - Ss. Cyril and Methodius University in Skopje, Faculty of
Agricultural Sciences and Food, Macedonia, 4- CREA Research Centre for
Agriculture and Environment, Bologna, Italy.
7. Seazonal canges in
mite ( Tropilealaps Clareae) and honeybee ( Apis Melifera) populations in
apistan treated and untreated colonies. E.S.W. Camphor, Pakistan, A.A. Hashimi,
Pakistan, W. Ritter. Germany, I.D. Bowen, UK.
Apiasta 40, 2005.
8. Акимов И.А.,
И.В. Пилецкая. О жизнеспособности яиц келещей Варроа.
Журнал Пчеловодство 1983 №8
9. И.В. Пилецкая
Особенности развития клеща Варроа Якобсони в пчелином и трутневом расплоде
10. А.И. Муравская
Влияние температуры и влажности на клеща. Пчеловодство 1984 №8.
No comments:
Post a Comment