When is the best time to delete the sealed brood in order to remove maximum Varroa mites from the bee family, and to protect the bees for the rest of the year.

As we have already said, a good method for both - for inhibition of swarming process and for reducing the number Varroa mites in bee families in the spring, is the method of removal of sealed brood, which is widely used in Europe. The reason of prevalence of this method is use in Europe of such a breeds of bees as Buckfast and especially Carnica. These breeds are characterized by an early start of egg laying by the queen, and very strong and rapid spring growth. This makes it possible to use brood removal in order to form early offshoots, for reduction of swarming mood in bee families, and for removal of  maximum amount of Varroa mites from bee families which are going to be used for honey collection.

This method has worked well in Europe and there is no reason why it can't be used elsewhere.... But, there is one interesting question... And when is the best time to remove sealed brood and how to determine this time?  This is the question we will try to answer ....

Let's define the criteria that we need... At first, we must have the sealed brood itself. It should not be much - one or 2 frames ... no more. Otherwise, we will take away a lot of energy from the main working family, which it will spend on feeding and heating of this brood.  Secondly, the forces of each family in which the brood will be collected from 3-4 families, should be enough to heat it.  Thirdly, in these one or two frames of sealed brood should be gathered almost all the mites that wintered on worker bees ...

When will this moment come and what is its indicator? We think, that free fall of dead mites on sticky board is a pretty good indicator. 

Throughout the winter, the mites drop have relatively small quantities, since the reproduction process was not possible or was severely limited by a small amount of early spring brood. This can be seen in all charts of counting of the mites drop in our four experimental families. A little more or a little less in each family, but on average, the values ​​are not high.

With the coming of warmth and the beginning of spring development of bees, Varroa mites also begin their development. Gradually, begins the growth of mites drop, consists of dark old mites . Behind it, with some delay, pale-colored immature mites appear in mites drop. This means that the mites have begun their active spring breeding phase. So right now it is needed to be interrupted.

It is at this moment, while the mites have not yet managed to increase their population, and it is necessary to start removal of sealed brood from the main working families, and to formation of  prefabricated families from it, which will later be treated with acaricidal preparations or natural acids. As soon as there are drones in bee colonies, fertile queens can be removed from these colonies. After their removal, the bees will lay queen cells on the remains of the open brood. And in a week or two,  young bees will come out from sealed brood and only flying bees and unfertile queens will remain in these families. There will be no brood for a long time. There is almost no honey in the nest at this time. And bees can be safely treated against Varroa mites, and with a high degree of efficiency. After processing, these bees can be used to make either non-honeycomb offshoots, or offshoots with honeycombs, or to strengthen those colonies from which the brood was taken.

At 55 degrees north latitude, and when working with Carnica bees, this is around mid-April. By the way, this can be clearly seen from the graph which shows the temperatures in the "streets" of the experimental hive in the period from autumn 2019 to early summer 2020.

The line graph shows the number of mites of both types falling on the sticky board per day. It is clearly seen from the graphs, that the growth of mites drop began in early April, when the bees began to confidently heat 3-4 frames in the nest (that is, 6-8 "streets"), most likely with brood. As a rule, the two central frames should already contain the sealed brood. This also confirms, that with the beginning of the growth of the mites drop, and with the presence of 2-3 frames of sealed brood, it can be removed from the bees family in order to remove Varroa mites together with it. At this time, the largest number of female Varroa mites should be exactly in it. Thus, temperature sensors located in the streets of the hive can be used in order to find this moment, if you do not want to often open the hive and to check the number of frames with brood ...

An additional element of the fight against Varroa mites at this time also becomes building frames from which it is necessary to regularly remove drone brood ( if it is not needed for breeding purposes), in which a lot of  female mites may present at this time of the year.

Instead of removed frames with brood, it is better to put clean combs in which the queen can immediately start laying new eggs, and to start feeding  bees with syrup. This will make it possible to avoid the weakening of families, which should work on honey collection, as much as possible. The developmental delay will be only a few days.

If it will be a good weather and if it will be a good supply of the families with  spring nectar, (and therefore in the presence of a large amount of brood) at the time period  before the onset of swarming season, this procedure can be repeated in whole or in part, both in order to extinguish the swarming mood of working families, and in order to create anti-swarming offshoots. The same procedure can be carried out immediately before the main honey harvest, which will free the bees from taking care of the brood and thereby will increase the production of marketable honey. Bee families in which the brood was transferred for further care, should be treated with formic acid. The bees obtained in these colonies, will be free from Varroa mites, and will be able, in the future, compensate the loss of strength of  families working at honey harvest, or will be able to become a source of bees for new offshoots ...

Thus, we found out that the best moment for removing of sealed brood from bee colonies, in order to reduce the quantity of Varroa mites, is the beginning of spring, when - 1) there are about two frames of sealed brood present in the family, and  - 2) at the same time the mites drop is just starting to increase in relation to the usual winter mites drop, and this situation means, that the female mites are maximally concentrated in the sealed brood in order to start the active reproduction process of new year.

 

Copyright   Sergey Glebskij   2020   ©  All rights reserved

Autumn 2020. First tests of bee families using Apivox Smart Monitor in winter mode.

It is late autumn now, and the bees are not doing any work outside the hive. When it is warm enough some bees can take honey from different places in the hive in order to supply another bees with food. There are bees that heat the central part of the nest in which the queen is located . Until it is not so cold,  (now about + 5C - + 7C) all signals inside the hive remain practically the same as in summer. This suggests that the bee colony feels normal and the bees are  engaged in normal in-hive works.

 But there are some peculiarities of diagnosing the state of bees in winter mode of operation of our device ... At first, you must switch it to winter mode (1), then you must make sure that you hear the signal of bees ... The picture of bees sounds must be clearly visible when amplification indicator is green or yellow... (2) If you see a red icon when trying to see the signals of bees, it is better to change the place of control, or to check the condition of bees personally...

At this time, if we will even slightly open inner cover of the hive or slightly knock on the body of the hive, the bees will be immediately excited ... To a certain extent, this interferes with the diagnosis, but this is normal and we should not pay attention to this. That is why even if there are such signals on the chart, (3) then we do not pay attention to them in the resulting diagnosis ...

Another feature is the behavior of the heating signals ... Usually, when the colony is in a normal state of hibernation, the heating signals are almost always small enough... (4) They are not the main ones, because it is enough metabolic heat which the bees emit without generation of any sounds, to heat the loose autumn cluster of bees. Therefore, the heating signal is small and the diagnostics do not mention it. If it is strong enough, then there is a high probability that brood rearing continues in the family and this is not a very good factor, since it allows Varroa mites to continue reproduction even in winter ...

The third feature is the possibility of presence of emergency heating signals. This is the lowest frequency signal in the hive. (5) And the most unpleasant one ... Its presence usually indicates, that the family does not have enough own heat to heat the nest and the queen, and this, in turn, suggests that there are too few bees left in the family to the beginning of winter. This is a very unpleasant sign, because there is a very high probability, that you will lose this family during the wintering process!

 Thus, diagnostics using Apivox Smart Monitor in winter time will not only show the state of the bees at the moment, but can give you a long-term forecast about their condition in future, if you will understand the relationship between phenomena about which we have just written ...

 Here are examples of diagnostics of two families remaining after 2 years of experiments on the Apivox Varroa Eliminator project. Until the last opportunity, these families did not receive treatment against Varroa mites, and suffered quite severely from it. Family 5-2 was very strong and produced 60 kilograms of marketable honey. But there were a lot of mites in it, especially after the finish of honey collection, and It suffered hard enough. Family 8-2 restored the queen in June and Varroa mites population in it became strong only at the beginning of autumn. We have not monitored these families for a month.

The family 8-2 showed a fairly good result. We can see 2 pictures - the first was taken in the Monitoring mode, the second was taken in the General State Control mode, that is, with averaging the results. We always choose an interval of 3 minutes as more indicative. Signals are clearly visible when the gain level is in the green zone. Family is in a working state. There is practically no excitement. Ventilation is episodic and is very weak when averaged. There is heating, but it is small and is not reflected in the diagnostics. In general, the family's condition is satisfactory.

Family 5-2 did not show very good results. We see the same 2 pictures. At first, we can see, that in order to see good signal of the bees we had to increase the gain - we see a yellow warning icon. This means that the sound of the bees is rather weak. In the monitoring mode, we also see the periodical appearance of the emergency heating signal. In General State Control mode, it also appeared, but unfortunately we did not take a photo. The second photo shows the presence of strong excitement. It would not be scary if it were not for the presence of the first signal - that is, the emergency heating signal ...

 

 

This most likely suggests, that 5-2 family is very small ... Most likely, there are very few bees and they have to heat the nest even at positive outside temperatures in a mode, that will lead to their rapid deterioration and death. This also explains the reason, that the bees are very easily become excited at the slightest touch of the hive ... Most likely this family will not survive in winter. The damage caused by the mites was too strong. There are almost no young bees left in the family which can survive until spring.

The check of the sticky board confirmed our assumption ... According to it, the size of winter cluster of bees is quite small!

And besides this, there are many mites on sticky
board, which fell down after the last treatment with amitraz. Most likely, not all the mites died.

 

Inspection of sticky board  from the family 8-2 showed,  that its size is also not very large, most likely it is about twice as large as the 5-2 family.

Thus, it can be assumed, that most likely, the 5-2 family will die before the beginning of new year. The family 8-2 has more chances to survive until spring, although they are not absolute...