NUMBER OF SMALL PEAKS OF VARROA MITES REPRODUCTION, ALLOWING TO REMOVE SEALED BROOD WITH THE GREATEST EFFICIENCY.

ANALYSIS OF DATA OF THE MITES DROP ON STICKY BOARD DURING THE SEASONS 2019-2020

 Analysis of data obtained during observations in 2019-20 unambiguously confirms the undulating nature of the mites fall, which is directly related to the reproduction process of both the bees and  the mites.

The graph of the average number of Varroa mites falling on the sticky board per day in the E1 family without regard to age - blue graph, and  the average number of immature and young unfertilized Varroa mites falling on a sticky board per day - yellow graph.

 

When analyzing the graphs, it can be seen that periodically,  there are sharp dips in the fall of the mites. This indicates, that the mites have entered the brood cells for reproduction. The deeper the dips, the stronger the mites drop splash will be after that ... The more female mites have entered the cells, the larger the next  waves of the mites drop will be .... Although, as we know, this connection is not direct ... The death and falling of the mites on sticky board occurs 2.5-3 months after their birth, and during this time the female mites  manages to produce 3-4 reproductive cycles ... The cycle looks like this - about 12 days of reproduction in the brood, 12-14 days of feeding on worker bees ... When these cycles coincide in a large number of females, and they all enter the brood together, then the fall decreases sharply by about the same 12 days, and as the young bees start to emerge from the brood, it slowly increases to its peak...

Simultaneously with the growth of free fall, the population of the mites also grows. After all, the larger the population becomes, the more mature females will begin to reproduce and the more they will die off in 2,5-3 months ...

It is also clearly seen on the graph that the fall of immature mites appears only at a high level of infestation, approaching the conditionally permissible maximum. According to the recommendations of the European and American Beekeeping Associations and scientists, up to 5 mites  falling on a sticky board  per day are permissible, and 10 mites per day are considered to be a critical tmount and such a family of bees require urgent treatment. These are more observational than real scientific data, but this is accepted in Europe, England and the United States ... The graph shows that with a small mites drop, we will not see immature individuals on sticky board, but when approaching the upper limit of the permissible range,  you will find on sticky board deutonymphs, immature females and young unfertilized females ... And this is the last warning that it is high time to urgently take action. And it is especially effective at such a moment to remove all sealed brood, immediately after the nearest sharp dip in the everage number of the mites falling on sticky board , which tell us, that  the mites already entered the brood cells for further reproduction! Although, with such a warning, it is already possible to take additional, less environmentally friendly measures such as the use of acaricidal drugs.

For example, let's look at the chart again. We see that in the first year (2019) after receiving the packeges with bees, which were treated with acaricidal preparations in 2018 and had a fairly low quantity of Varroa mites, the family reached the critical point in the size of the mites population only before the beginning of August. This was also helped by the creation of a brood-containing offshoot  from the part of this family. But, if the bees had not reduced rearing  of brood in the fall, then death of the bee family could have occurred already in 2019. Death did not occur and the mites went to winter together with the bees ... The population of the mites successfully overwintered and began to recover imperceptibly in late winter-early spring ... And as we can see, it showed the first massive entry into the brood around April 4, and the warning about the need for urgent action appeared already around April 21 ... The first immature mites  appeared in the mites drop! This means that  the amount of the mites entered the brood cells  on April 4, was very serious !!! A huge number of young mites came out of the cells together with young bees! And indeed, the next generations of the mites finished off this family in May !

Thus, it can be stated that if the beekeeper controls the mites drop on the sticky board, then he has an excellent tool for determining the moments when it is the best time comes to remove sealed brood and remove up to 80% of mites or more from the bee colony ... He is no longer blind and helpless in front of these hidden parasites, and can quite clearly see all the ideal moments for inflicting the most painful blow on them. In addition, it can be stated that there are a lot of such moments, and the beekeeper only needs to choose the moment to strike the mites population, which corresponds to the strength of the bee colony. If the moment of mass entry of the mites  into the brood in spring has come, but the strength of the colony is still insufficient for removal of the brood, then the beekeeper will have to continue controlling the mites drop in order not to miss the next opportune moment. But now we understand that there are several such moments, and having missed one of them, we can always wait for the next appropriate moment. It is always important to know what lies ahead and what we can count on. And this is the path to success in any struggle!

So, what a beekeeper-practitioner should know ...

If, when controlling free fall of the mites on the sticky board, after successive growth, there is a sharp drop in the average number of mites falling on the sticky board per day, then we can say that there has been a massive entry of the mites into the brood for reproduction. With low quantity of the mites population and in springtime, the dip can be up to zero, or to values ​​close to it. In summer and autumn, with a high values of the mites in bee colonies, the drop may not be up to zero, but to values ​​significantly different from the previous trend ... And this means that the best moment has come for removing brood from the colony (or destroying it) in order to sharply decrease the mites population in a colony of bees ...

The duration of such a dip is about 12 days, and if you control the mites drop once every 7-10 days, then you will never miss it!

 

REMOVAL OR DESTROYING OF THE BROOD OF WORKER BEES - WHAT IS THE BEST METHOD OF COMBATING VARROA MITES.

Today we will consider two methods of Varroa mites control, which are based on the destruction of mites that are in the process of reproduction in the brood of worker bees.

One of the methods, namely the sealed brood removal method, has its roots in the beekeeping traditions of Germany. This method is fairly well known for removing drone brood during the pre-swarming season when drone brood is exposed to mite raids. Removal of the frames with drone brood is already a classic of the method. The brood removal method we are working on this year is somewhat more complicated and has 2-3 stages. But it is based on the same actions as when working with drone brood.

The second method came to us from Spain and is practiced by some professional beekeepers who believe that it is faster and more convenient than the brood removal method ... This is a method of destroying the sealed brood of worker bees in the period before honey harvest. This method consists in the fact that the beekeeper, using honey fork or similar, quickly destroys all cells of infected by Varroa mites sealed worker  bee brood on all frames in the nest. The damaged brood is not removed, but the frame is placed back in the nest. It is believed that the mites and all their offsprings will also die in the destroyed cells. After that, a strip impregnated with a slow-acting preparation of amitrase is placed in the nest to treat worker bees from the mites feeding on them.

Let's consider the pros and cons of both methods, which are so close in essence, and so different in execution ...

The brood selection method is somewhat longer than the method of its destruction and requires more resources. If the process of working with nest frames is completely the same - you need to inspect the entire nest and to select all frames with sealed brood, then further actions when shredding the brood are easier and faster. You need to take a fork and quickly destroy the cells and to  damage the brood of bees. When removing brood, it is necessary to select technical colonies for collecting brood and to move the frames with the sealed brood in them. After that, it is necessary to ensure the emergence of young bees from the brood in technical colonies in the absence of new brood, and to treat them with natural acids or acaricides. At the same time, the main families of the apiary will  remain free of chemicals. When the brood is destroyed, the procedure does not end there either ... Strips with amitraz are placed in all hives with destroyed brood, which slowly evaporates and kills some of the mites parasitizing on the bees.

 

Destroyed brood mixed with polen from neighboring cells becomes protein feed for worker bees, who will clean and restore destroyed cells, simultaneously throwing out dead mites ...  But, there is a high probability that the founding female mites in the destroyed cells will not die completely, but will climb on worker bees, who will come to restore these cells ... That is why it is impossible to talk about the real effectiveness of this method. Ideally, it should be equal to the effectiveness of using amitraza in a family without brood, that is, about 80-90 %% ...

The efficiency of removal of sealed brood for families from which it is removed, is approximately 80%, but it can be even higher when removal of the  brood is made at the moment of the first mass entry of the mites into the brood cells for reproduction, when almost all sexually mature wintered females and young females born in winter and early spring if the winter was warm enough ... For technical families, the processing efficiency is also 80-90 %%, depending on what medicine was used .

It is advisable to use both methods on bee families with sufficient strength after leaving wintering. Destruction and removal of sealed brood shifts the development of colonies by 10-15 days, depending on the number of removed or destroyed combs with brood ... Therefore, in both cases, it is important that bee families have enough food, bee bread and bees to accelerate the rearing of a new generation of young bees.

But these two methods have one significant difference ... If during the destruction of the brood you lose a huge number of future bees, then during the removal of the brood, all these bees will be saved and new colonies can be created from them or the very colonies from which we selected them, can be strengthened.  This way the apiary will be more efficient and will collect more honey and give more packages. In addition, when rearing queens, such powerful prefabricated families can be used as a families-rearers for new queens! The removal of the old queen, the exit of all young bees from the cells with their subsequent processing with acids or acaricides, in fact, without any additional operations, turn these technical families into the families-rearers of the queens!

It is important to add here that both of these methods, according to our calculations, will not be effective in a one-time applying and will be only more or less effective in a two-time applying ... This is what we see in practice. Varroa mites from apiaries do not disappear, and at best they only subside until next spring. Let's show this with a simple arithmetic calculation ...

If in the spring of this year there were 100 mites in a family of bees, then processing them in any way with an efficiency of about 85% will reduce their number to 15 pieces. For 6 months of active reproduction, the mites population will grow 2 in the sixth degree times (doubling every month according to scientists) or in 64 times, and if you are not lucky, then in 128 times. Thus, by the end of the season, there will be from 1000 to 1900 mites in the bee colony. With a one-time treatment, 5% per month will die during the winter, or an average of 30%, and in the spring there will be from 700 to 1200 mites in the family, and this will result in death for the bee family in the spring or in the beginning of summer. With a double-time treatment with an efficiency of about 85%, only from 150 to 220 mites will remain by winter, which, after a decrease of 30% during the wintering period, will ensure in spring the presence in the bee family  from 100 to 150 mites. Basically, we're back to where we started ... even a little worse ...

That is why we say that any of the currently existing methods ensures only the preservation of bees and mites in such a way that the bees more or less survive, and the mites continue to feed the manufacturers of chemical preparations! Thus, we believe that the only way to win this battle without watering the bees with bipin ( amitras-based preparation) seven times per season, as some Belarusian producers of packages and honey do, is to reduce the rate of mites reproduction between spring and autumn treatments - that is, in summer! And this is the main goal of our Apivox Varroa Eliminator project.

AN IMPORTANT TENDENCY IN THE STATE OF VARROA MITES FALLING ON THE STICKY BOARD, WHICH CAN BECOME A MARKER OF THE MOMENT, WHEN IT IS THE BEST TIME TO REMOVE SEALED BROOD, WITH THE GOAL TO ELIMINATE VARROA MITES POPULATION IN BEE COLONY.

As you know, in 2021, our Apivox Varroa Eliminator project start  testing a method of removal of sealed brood to combat Varroa mites. In our experimental apiary, 5 families of bees have been allocated for this. Four of them are in various modifications of our new hive, the fifth (T1) is intended for collecting infected sealed  brood, removed from the rest of the colonies. Testing of the technique began in early April, when there was no brood in the families of bees which we use this season at all.

One of the questions we face in the spring is the question of determining the best time to remove sealed  brood ... And this is what our observations have shown ... An interesting trend has been noticed ...

In the E1 hive in which we removed the only frame of sealed brood 6 days ago, the old mites continue to fall from the worker bees, as it was during the winter and early spring. But in hives E2 and T1 there was a sharp decrease in mites drop to almost zero ... in E2 already within 11 days, and in T1 already within 6 days !!! But in E2 we did not remove the brood,  and in T1, on the contrary, we collect all brood removed from the other hives ... It would seem to be a paradox ... but it is not!  Exactly in the E1 hive, in which there is no brood left for reproduction, the mites end their life on flight bees and fall down at about the same rate as when there was no brood at all!  In the hives, in which 2-3 frames of brood remained, which were eventually sealed during these days, there was a sharp decline in the fall of the mites ... The graph clearly shows that the brood in the E2 hive was sealed approximately 11 days earlier, and on examination we saw that young bees would begin to hatch soon, while the brood in the T1 hive was sealed 5-6 days later. This can also be seen in the color of the lids ... they are still quite light.

Everything is correct! Apparently, all the old female mites went into the first mass brood for reproduction, and there are practically no mites on the bees !!! There is no one to fall down. Old females that will die off during the breeding process will be thrown out by the bees when cleaning the cells only after the young bees emerge from the brood and will end up on the board under the frames with the brood, again sharply raising the average number of falling mites per day !!!

Thus, a sharp drop, almost to ZERO, of the mites falling on sticky board in spring, when the bees set the first mass brood, indicates that practically all Varroa mites are in the brood cells and the best time has come to remove all them from the bee family !

The only question is the strength of the family, which will be left without sealed brood for about 10-14 days .... But if this happens in mid or late April, then in spite of removal of the sealed brood, which will be restored in about 10-14 days, for family development will remain the whole May with the best weather and food supply. At the same time, the maximum possible number of Varroa mites will be removed from the family. As we can see,  they are  practically absent on the bees at all. This is evidenced by the absence of the mites falling on sticky board for almost a week or two ...

So, in essence, we have found the marker that should help practical beekeepers to define the best time in spring,  for removal of sealed  brood, in order to clean the colony from Varroa mites without the use of chemicals.

Control of brood quantity in the middle of April

 In previous article, you saw the results of diagnostic readings of Apivox Smart Monitor, used in brood control mode when no brood was visible in the family, neither open nor sealed.

Today the diagnosis is radically different. In all colonies 1-2 frames of brood, moreover, mostly open. There are not too many sealed brood. 

Pollen appeared in nature and the bees began to actively hatch the brood!