In
the frameworks of our Apivox Varroa Eliminator project, we continue to review
and analyze the state of the bee's families and the mite's population living in
this families, using the method of
counting free fall of the mites on sticky board, and we believe that this
method, although it does not yet allow one hundred percent accurate numerical
data, can help to determine key points in the development of bee's families and
the population of mites parasitizing on them.
For
a long time scientists tried to adapt such a parameter as the mites drop, for
prediction of the degree of mites, parasitizing on the bees in the colonies ...
But everyone wanted to get specific numerical data, even by simply adjusting
the numbers to the needed results ...
On
the basis of this method, the ministries of agriculture of the United States, Britain, Spain and other countries
distribute, their own recommendations
and methods of Varroa mites' control. On the basis of the average number
of mites, falling on sticky board per day, it is proposed to build the strategy
for treating bees with acaricidal drugs!
Representatives of the agricultural industry, trusting scientists, made
the method of calculating the free fall of Varroa mites, the main one for
estimating of infestation of bees' families, as the least laborious.
It
is believed, that it gives fairly accurate results. But sometimes it's not
quite right, and sometimes it's not right at all .... We came to this
conclusion for two reasons:
The first reason - is that in different works of scientists, who studied and
evaluated the accuracy of all known methods of calculating of the quantity of
Varroa mites in bees families, it is
written, that all methods are equally not accurate at the beginning and at the
end of season, when the number of mites in the family is too small. And that in these works, scientists use at
least three different coefficients to translate the amount of daily free fall
of mites, into the total number of mites in the family of bees. We know
that scientists use this special
coefficient, by which, the average daily fall of mites is multiplied ... It is
equal to :
1) 20 in spring, and to 40 in summer and to 250-500 during broodless season. ( Population model for the ectoparasitic mite Varroa jacobsoni in honey bee (Apis mellifera) colonies Stephen Martin National Bee Unit, Central Science Laboratory, Sand Hutton, York, YO4 1LZ, UK )
2)
120 throughout the season. (Development of the mite, Varroa jacobsoni
oud., in the honeybee, Apis mellifera L., in Michigan, USA, and a comparison of
diagnostic methods for detection of the mites Ahmad Al Ghamdi and Roger
Hoopingarner )
3) 170-200 throughout the season. (GUÍA TÉCNICA PARA
PARA LA LUCHA Y CONTROL DE LA VARROOSIS Y USO RESPONSABLE DE MEDICAMENTOS
VETERINARIOS CONTRA LA VARROA DIRECCIÓN
GENERAL DE SANIDAD DE LA PRODUCCIÓN AGRARIA
SUBDIRECCIÓN GENERAL DE SANIDAD E HIGIENE ANIMAL Y TRAZABILIDAD)
This
already suggests, that each researcher adjusted the coefficient to the
situation in his apiary, or in his zone.
And even this fitting does not
work if used in mathematical models, which are compared then, with the real
results of counting of Varroa mites in the brood and on adult bees... (Population
growth of Varroa destructor (Acari: Varroidae) in honey bee colonies is
affected by the number of foragers with mites Gloria DeGrandi-Hoffman Fabiana Ahumada Victor Zazueta Mona Chambers Geoffrey Hidalgo Emily Watkins deJong)
It must be
said, that counting of a quantity of
mites, using another methods is not much better ... Counting the quantity of
mites, parasityzing on adult bees is not indicative since in summer, up to 70%
of the mites are situated in the sealed brood... analysis of the sealed brood
are not accurate due to the uneven distribution of the mites in the brood and
due to the presence of a part of the mites on adult bees ...
Calculation
of the percentage of mites in any form is also not an indicator... With different strengths of bee families, the
same percentage can mean a multiple difference in the real number of mites,
which, in the process of development of bee families and reproduction of mites,
leads to a multiple difference in the percentage of mites when the strength of
bee families will become equal...
For our
project we invented our own method of calculating of mites drop. It consists in
a separate count of dark - old, already participated in reproduction females, and
pale-colored young female mites and deutonymphs, which died or did not
fertilized by a male mite inside the cells, and were thrown out by the bees. We
call this the two-graph method. So, what is its meaning ...
The point
is that in addition to the fall of an old dark mites, that is clearly visible
to everyone, there is another process - the process of death of young females
that have not yet participated in the growth of the mite's population. Pay
attention to the photo ... It shows the mites, which fell down on sticky board
of our experimental hive in different seasons of the year.
They all
have a different color !!! Mature old
fertilized females are deep red and burgundy! Young females have a bright red
color that is darker or lighter depending on maturity, and the paler ones are
not mature females and transparent individuals are deutonymphs ... In order to find this facts, we had to turn to
authoritative documents ....
(Managing Varroa.
Published by The Food and Environment Research Agency. Printed in the UK,
November 2010, www.defra.gov.uk/fera )
On the diagram we see once
again the confirmation of our practical results - 1) Varroa mites in the summer
live 2-3 months. In practice, we see about 2.5-3 months. 2) Immature and not
fertilized young females do not survive. 3) The final red-brown color of Varroa
mites is gained after the last molt ot the mite, when it become fully grown and
capable to lay eggs. Young females does not have such a color. They are paler. The color is closer to
brigh-red. Confirmation of this item we took from another document ...
(A deadly honey bee parasite The Varroa Mite PUBLISHED BY
Bayer AG beecare@bayer.com www.beecare.bayer.com )
"...Graphic
showing Varroa mite development stages The first development stage of the
Varroa mite is a six-legged larva that develops inside its closed egg. The
eight-legged protonymph emerges in the post-hatching second stage. In the third
phase this protonymph develops into a deutonymph, which then becomes the adult
mite. In the final nymph phase, the growing mite undergoes two immobile
transitional chrysalis stages (protoand deutochrysalis). Young female nymphs
are white in color and, after molting several times during the development
process, turn dark reddish-brown during the last immobile stage – the
deutochrysalis – and maintain this color as adult Varroa mites..."
So, the
method of two graphs that we use, assumes separate counting of dead old females
of the mites, dying during or after breeding, and dead young females, that did
not participate in breeding. Shifting back the graph of mites drop of mature
dark mites by 2.5-3 months, or by the approximate lifespan of the tick, we can
talk about the approximate time of their birth, and we can analyze the events,
that led to their appearance and development in the bee colony. The appearance
of the mite's drop, consists of pale mites is, according to our long-term
observations, a very bad sign, and speaks of an over-intensive reproduction of
the mites, when it uses all brood zones for reproduction, even that are
not too suitable for reproduction in
terms of their parameters. Thus, using two graphs, we can learn about the past
of the mite's population, about the prospects for its increase in future, and
about the intensity of the process of
growth of the mite's population at the moment.
In general,
free fall of the mites at the time of testing is not always indicative. There
are intervals, as we can see from the graphs, when there is practically no
mite's drop or it is small ... This does not mean that there is no mites or its
number is small... It is just mean, that the mites are waiting for suitable
conditions for mass reproduction.
From the
graphs we can see, that the mass death of the mites of all ages is directly
related to the cycles of enhanced reproduction, which apparently takes away the
last strength from the old individuals and leads to their death... In this case, the idea that the mites live
for about 2-3 months and the method of shifting the graph of free fall of the
mites by 2-3 months back shows the time
of their birth, allows us to see the real time of birth of this mass of falling
mites ... And these are the months, when it seemed to us, that there was almost
no mites or very few... In particular,
so was in January-February 2020, as can be seen from the graphs below ...
The graph of free fall of the
mites (mites per day) in 4 families of our experimental apiary during 2019-2020
years
An analysis
of the graphs of free fall of the mites obtained by us during 1.5 years of
continuous observations of 4 families of bees, shows the following ...
Almost
throughout the winter, except November and December, the mite population had
the opportunity to reproduce and maintain its existence, since the bees had
brood due to the warm winter and wintering in a pavilion heating by the sun.
This led to the fact, that the first massive release of new mites and the fall
of old and immature mites coincided with the honey harvest from the willow on
about April 23rd. The influx of large volumes of nectar and pollen led to the
first mass release of young bees from the brood, and accordingly, to the first
powerful release of the mites. The second release took place at pre-swarming
time from 11 to 30 May, when the number of brood at least doubled, and was laid
drone brood. All these led to the next
outbreak of the mites population.
In colonies
5-1 and 5-2, the growth of the mite's population during the main honey
gathering stopped due to a reduction in brood quantity due to the filling of
the nest with honey, but at the end of it, the mites began to reproduce again.
The family 5-1 lost its queen and was left without open brood for a couple of
weeks. The mites drop in it has grown quite insignificantly, and then it
sharply decreased. But in the 5-2 family, at the end of honey harvest, free fall of the mites of all ages again
sharply increased to close to critical values.
In the E-1
hive, the growth of the mite's population was so strong that, when the swarming
began, it led to a complete loss of the family. The reason is that this family
with an old queen had already laid swarming queen cells by May 7. The sharp
increase in the amount of well-heated brood resulted in a powerful increase in
the mite's population. As a result, in
the family, there were a lot of sick and dead larvae in the brood, and sick
young bees. All infected brood was abandoned. The family, despite the removal
of swarming queen cells and the division in half, flew away in the form of two swarms.
In the hive
8-1, a similar picture began with some lag behind E-1. The bees of this family
also laid swarming queen cells, but the queen in this family was young, and the
removal of queen cells led to the termination of the swarming mood of the
family. Despite this, it was laid a lot
of drone brood , which caused the subsequent increase in the mite's population.
The growth of the mite's population began in this family too, but a little bit
later, on the background of honey collection, since the family was not quite
ready for it and began to bring marketable honey later than 5-1 and 5-2 ... In
order not to lose the family, were taken
a measures, as you can see on the graph, on June 23. One frame of drone brood was removed and was
completely destroyed drone brood on all
other frames. The fall of immature and mature mites dropped sharply. This
indicates the possibility of temporarily suppressing of the development of
mite's population in pre-swarming time by removing the maximum amount of drone
brood. But at the end of the honey harvest, the mites were able to develop
vigorously again, and the fall of the mites of all types increased sharply to
close to critical values.
So, what
did our observations show in general ...
1)
Observations show on the example of all families, that each next burst of the
mite's reproduction is at least 2-3 times stronger than the previous one. This
difference roughly corresponds to the amount of mature mites fallen free during
the present reproductive cycle, divided by the amount of fallen free immature
mites of the previous reproductive cycle... The value is approximate, but it is
confirmed in all experimental families. You can see it on the graph.
2)
Observations show that swarming state of bees should be avoided by all means.
It is the massive laying of drone and bee brood before swarming and, most
importantly, its thorough heating by the bees, that leads to a catastrophic
increase in the mite's population due to a multiple increase in the
reproductive territory, comfortable for it.
What
happens in this case with the bee family? Let's have
a look...
In
the course of our scientific work and acoustic monitoring of bee colonies using
our Apivox Smart Monitor device, we came to understanding, of the changes, that
occur in the bee nest in pre-swarming period ...
The
fact is that at the beginning of the process of preparing for the swarming, the
task of the family and the queen is to build up the maximum possible strength
of the family before the swarm leaves. Then, dividing in two, the family will remain
large enough to survive and collect honey for the wintering. To do this, the
queen begins to fill all the cells in the hive suitable for this with brood ...
But the nest is not the whole hive, and the bees do the following !! They start
powerful heating of the ENTIRE hive ! The whole hive turns into a nest! The
earliest queen cells appear on the periphery of the nest - on the second frames
after the extreme honey frames ... It was at this moment when a specific
acoustic signal appears in the hive, which we use as a sign of an impending
swarming, which Woods considered to be a signal of young bees, and prof. Eskov
mistakenly considered to be a signal of passive bees .... A signal, that accompanies heating of the hive and a
signal that accompanies heating and aeration of open brood. These signals
becomes so powerful, that they dominates in the hive even in the daytime,
suppressing the signals associated with the work of bees on honey harvest!
This
event in the life of a family of bees becomes the "golden" time for
Varroa mites and the cause of the subsequent troubles of bees ... down to their
death .... Now the mites can actively reproduce in a huge amount of brood, and
not only in brood of worker bees, which used to be warm enough even earlier, and also to reproduce actively in drone
brood... This at least doubles their breeding potential, which ultimately leads
to exponential growth of the mite's population in April-June.
Such
a leap in the growth of the mite's population occurs primarily in the families, which are initially ready for swarming - that
is, in the families with old queens. It
is possible, that this was the reason for the confidence of many beekeepers
that bee families with young queens are better able to cope with the mites. But
it is normal thing, in the families with young queens, bees are less prone to
swarming, which means, that they are less prone to heating the entire hive and
to the massive construction of drone cells, which become a "bomb"
placed under the colony during swarming time. In normal times, drone brood
located in cool areas of the hive does not create such an "incubator"
for the mites, and colonies that do not enter the swarming state suffer from
the mites much less.
The
use of anti-mite's techniques associated with expansion and, as a consequence,
with cooling of the nest, will worsen the mite's reproductive capabilities and,
possibly, save the bees from death in the event of a high infection of the
bee's colonies in spring.
Basing
on this, we can say, that in springtime, early diagnosis of swarming state of
bee colonies become a very important point for a beekeeper who want to get
ecologically pure honey. Using Apivox Smart Monitor application, you will be
able to know about it at least 2 weeks before the start of the swarming
process, or even earlier, and will be able to understand, that it is high time
to take measures, which will not only help to avoid losing of swarms and honey,
but will also dramatically reduce the number of mites in bee colonies.
3)
Observations show that if, during the next cycle of enhanced reproduction, free
fall of an immature mites significantly exceeds free fall of an old mature dark
mites, and has sufficiently large values, then this is a very alarming signal.
It can be assumed, that not only a large number of young mites were released,
but the founding females did not die ! Thanks to this, accumulates the mass of
live mites, ready to participate in the new reproductive cycle, and exactly
this make the next flash of reproduction so powerful.
During
the main honey flow period, when the mites have less bee's brood in the nest
for reproduction and worsening climatic conditions in the nest, overall
reproductive opportunities of the mites reduces. Free fall of the mites sharply
reduces or stops altogether ... The mites of reproductive age are waiting for
the optimal moment to start laying eggs ... With a decrease in the flow of
honey at the end of the main honey harvest, as well as with removal of honey by
beekeepers at the end of summer, the volume of free space for laying eggs by
the queen increases ... The weather conditions at this time, in
August-September, are still favorable for the bee's brood rearing and for the mite's reproduction. At this
time, beekeepers are trying to get as many young bees as possible, because
exactly these bees will winter and form a family next year. Under these
conditions, starts new powerful laying of brood by the mites, which, as a rule,
leads to a powerful autumn surge of the mites population, and during release of
young bees from the cells, to a strong fall of old mature females, and immature
young female mites.
All
this can be seen in the diagrams for families E-1 and 5-1.5-2. It was in the
E-1 family, which showed the greatest growthof free fall of pale immature mites, and as a result, a
sharp increase in the mites population till a critical numbers. This led to the loss of the family. In families 5-1 and 5-2, the number of immature
mites falling free on sticky board was
significantly less, and it needed about two months for the mite's population,
to grow to almost the same size as in the E-1 family.
4)
Observations show, that the state of a bee colony when a quantity of falling
mature mites reaches quantity up to 5 mites per day, in principle, is not too
bad for a colony of bees of almost any strength. The bees of a strong family
can even withstand situation, when a
quantity of falling mature mites reaches 60-70 mites per day, for up to a
month. They are also can withstand
situation when a quantity of falling mature mites reaches from 20 to 40 ticks
per day, for 2-3 months. Of course, in the bee's family appear many damaged
bees that are unable to fly, and this weakens the family and reduces its honey
productivity... We can see such a situation in the graphs of three families of
our experimental apiary - 5-1, 5-2, 8-1. At the same time, 8-1 and 5-1 produced
about 40 kilograms of marketable honey, and a 5-2 family - 60 kilograms, while
being in a stationary apiary. Thus, we can say, that the state of a bee colony
when a quantity of falling mature mites reaches quantity up to 10 mites per
day, in principle, is not terrible in the short term for a strong colony of
bees. The danger appears when, in addition to mature dark-colored mites,
immature pale-colored mites appear on sticky board. This is a signal of alarm.
This is a sign of an incipient reproductive "outbreak" of the mites.
So, as you can imagine, the main task of beekeeper is to combat these periodic
reproductive outbreaks! Their suppression should be the main task.
What methods can be used for this... Let's consider these methods in
chronological order in accordance with the life of bees ...
Wintering:
The first step in keeping bees properly in terms of Varroa mites control
- is cold wintering. This method has been known in Europe for a long time. Carnica - is a
European bee breed and it is in Germany that they know how important it is
to suppress its natural tendency to constant brood rearing. It is very
important to make bees to stop brood rearing early enough, and to start brood
rearing as late as possible. It is very bad when the bees finish growing the
brood in November and start growing it again in January. It is thanks to this
that the mites can slowly and imperceptibly increase their quantity during
winter, and with the first abundant spring bees' brood, can sharply increase
size of their population to critical values. This is how our E-1 family died.
The graph clearly shows that exactly in this family we can see fairly strong
fall of old mites throughout the winter, and already in April we can see the
appearance of a peak in free fall of immature and mature females - that is, a
powerful surge in the reproductive activity of the mites.
It is
ideal, if bees, especially Carnica bees, begin to actively rear brood with the
arrival of stable heat and appearance of pollen sources in nature. It is from
this moment and not earlier begins the active development of bee families . At
this time, if the bees have warm nest
and are supplied with nectar and pollen, they build up their strength
surprisingly quickly, especially in the case of the bees of Carnica breed.
In other
case, exactly population of Varroa mites, rather than the population of the
bees, develops and renews better. That is why in Europe and especially in Germany, cold wintering has acquired
particular importance in the fight against varroatosis. It is exactly cold
wintering should not allow the mites to multiply during the winter, when
beekeeper cannot help the bees to get rid of them. It is this event that will
help to avoid the first spring peak in the growth of the mite's population. And
here we can say, that design of our new hive, or rather its inner cover, makes
it easy to provide the bees with both - cold in winter and with warm in spring.
Spring
development till the main honey flow: The
main methods of influencing the mites population in this period are: the reduction of the space suitable for the
reproduction of the mites and the deterioration of the conditions, required for
their reproduction. Several techniques can be involved here together or separately ...
1) Creation
and maintenance of young families. Creating young families in the
apiary to replace old working families by forming artificial swarms, by forming
offshoots with mature queen cells, the beekeeper "kills two birds with one
stone at once." Firstly - when
creating such families, the brood which at this time is the main repository of
the mites, is not used or is used minimally. Secondly - such colonies are easy to process in any way,
including using of formic acid, which is a method, that minimally contaminates
frames and honey. Thirdly - the families
will have young queens, which is an excellent anti-swarming technique. Such families,
as a rule, have a good start in development and begin wintering healthy and
clean.
2) Suppression
of swarming state of the bees in order to deprive the mites possibility
of super-active reproduction in a huge amount of well-heated brood of worker
bees and drones. Before the start of the main honey collection, possible
methods are: the presence of young
queens, expansion of the nest, removal of maximum possible amount of drone
brood. Firstly, as we have already said, colonies with young queens are, in
principle, much less prone to swarming. Secondly, the expansion of the nest
reduces swarming mood of worker bees and deprives mites of a large, well-heated
brood zone and, most importantly, a well-heated drone brood. Thirdly, the use
of building frames allows not only to reduce swarming mood of the bees, but
also to remove from the hive and destroy almost ninety percent of drone brood with mites in it, with a minimum
expenditure of efforts and without injuring the bee family.
3) Removal
of sealed brood. Removal of frames with sealed brood, which can be
carried out during the period of bee's families growth, till the main honey collection, in order to
prevent swarming and to create offshoots, also sharply reduces the number of
mites in bee colonies, and significantly contributes to the fact, that the
disease does not take on a threatening character in the main colonies until
autumn, even in the absence of other mites control measures. In addition,
holding such an event in June can, under certain conditions, increase honey
productivity of bee's families by reducing number of bees engaged in brood
rearing. At the same time, the families from which the brood was removed, can
be treated with formic acid, and this treatment will be very effective at this
stage.
In the
process of honey collection, bees themselves usually create conditions, which are not very good for
the mites reproduction ... This can be seen from the graphs of free fall of the
mites in all four families. ( June-mid of July)
But even at this time, it is possible to influence the mite population using
methods of temporary limitation of queen egg laying, and removal of sealed
brood. Unfortunately, such measures during the period of honey
collection cannot be radical, otherwise there will be losses of marketable
honey due to weakening of the strength of bee colonies.
Autumn
preparation of bee families for wintering. It is possible that you can again use
the method of removing the sealed brood, and then proceed to cooling the nest,
in order to stimulate the end of brood rearing season. In this case,
the first task is to interrupt the mite reproduction chain in working family.
Using this method, beekeeper can remove most young mites and founding females
into a separate colony, which will be a subject of radical anti-mites treatment
after the entire brood will release. At the same time, in all families from
which the brood will be taken, should be given new combs, in which the queens
will begin to lay eggs, from which will born the bees, which will go wintering strong and healthy. At the same time, a huge
number of mites will be removed from working bee colonies, and will not be able
to start a new reproduction cycle. This should be done at the very beginning of
the growth of peaks of free fall of the immature mites, which means, that a lot of mites already entered the brood
cells for reproduction. The second task is to ensure a smooth transition of
colonies to cold wintering with corresponding decrease and further termination
of brood rearing.
The use
of our new Apivox Varroa Eliminator project and a new method of keeping bees
takes a special place. Using this method, we managed, although not to completely suppress the
development of the mites population in the experimental family, but to reduce
significantly their growth rates in summer ... Today we believe, that the
design of the hive, although correct, is still not optimal. But even today it
has certain advantages ...
- Its
design makes it easy to control the mites drop, in order to understand the
processes occurring in the mites population.
- Its
design allows to ensure the autumn transition to the winter regime and cold
wintering of bees, as well as their warming in the spring and summer.
- Its
design allows to accelerate the development of families in spring and summer, while reducing the
intensity of mites reproduction.
An analysis
of data from the past 2019 showed, that if we can consider free fall of the
mites proportional to their number in the bee colony, or to the size of the
mites population, then, the growth rate of the mites population in the
experimental hive number E-1 did not exceed six times, despite the fact that
the family had an old queen bee and a lot brood, while control colonies, some
of which had young queens born in this year, and which had less mites, had growth
rates from ten to one hundred times... In this case, we are talking about
relative values. The absolute values of free fall of the mites in experimental family were initially higher
than in the control families, but by the fall these values were almost equal
... In the end, not the design of the hive led to the death of experimental
family, but the need to conduct observations of the development of the mites
population in it even till its death!
In
general, new hive showed that the bees
can live and develop in it, and we can select its parameters in order to
suppress the development of Varroa mites to one degree or another. But this
will have to be done again next season, in order to obtain more statistically
reliable results.
So, we are
confident that application of the above rules of keeping bees throughout the
year and the use of our new hive will be able to jointly solve the problem of
preserving bees and of suppressing the development of Varroa mites in their
families.
Here we used diagrams and drawings from the works:
1.
Population model for the ectoparasitic mite
Varroa jacobsoni in honey bee (Apis mellifera) colonies Stephen Martin National Bee Unit, Central Science
Laboratory, Sand Hutton, York, YO4 1LZ, UK
2.
Development of the mite, Varroa jacobsoni oud.,
in the honeybee, Apis mellifera L., in Michigan, USA, and a comparison of
diagnostic methods for detection of the mites Ahmad Al Ghamdi and Roger
Hoopingarner
3.
GUÍA TÉCNICA PARA PARA LA
LUCHA Y CONTROL DE LA VARROOSIS Y USO RESPONSABLE DE MEDICAMENTOS VETERINARIOS
CONTRA LA VARROA DIRECCIÓN GENERAL DE
SANIDAD DE LA PRODUCCIÓN AGRARIA
SUBDIRECCIÓN GENERAL DE SANIDAD E HIGIENE ANIMAL Y TRAZABILIDAD
4.
Population growth of Varroa destructor (Acari:
Varroidae) in honey bee colonies is affected by the number of foragers with
mites Gloria DeGrandi-Hoffman Fabiana
Ahumada Victor Zazueta Mona Chambers
Geoffrey Hidalgo Emily Watkins deJong
5.
A deadly honey bee parasite, the Varroa
mite. PUBLISHED BY Bayer AG
Copyright Sergey Glebskij 2020
© All rights reserved
https://sites.google.com/view/apivox-varroa-eliminator-eng/results-years-2019-2020
