The results of alcohol wash during the control of infestation of bee colonies by Varroa mites and the corresponding survival or death of bee colonies.

In all scientific papers and official recommendations of the beekeeping communities in the USA, Britain, Spain and other countries there are tables with recommendations at what quantity of Varroa mites on a sticky board, and at what percentage of colony infestation by Varroa mites, certain measures must be taken in order to combat mites that infect this family of bees. Sometimes it is just a continuation of monitoring the colony, sometimes it is suggested to carry out treatment after an interval of 2-4 weeks, sometimes treatment is required urgently ... It all depends, of course, on how severely the colony of bees is affected by Varroa mites.

But, unfortunately, these tables do not quite correctly describe the situation that takes place in a colony of bees affected by Varroa mites. We have learned this from our sad experience, working with control families in our experimental apiary.

The mistake here is that these tables show the values ​​of infestation, as it were, in development - spring, summer, autumn. And it seems that if in the spring the percentage of colony infestation on the basis of an alcohol wash is set at 1-2%%, then it seems to the beekeeper, and sometimes such a table directly says, that there is no need to do anything in the next 3 months. This is completely wrong and this is a big mistake. If we take a family that will not be subjected to any chemical treatments, then we can say with confidence that the growth of Varroa mite population is 2 times a month. This is scientific evidence and we have also seen this in our experimental families. The experiment involved 7 families, and the results fell into this graph with high accuracy.

 

The theoretical graph starts with the percentage of colony infestation equal to 1%, the real schedules of families have their own, sometimes unknown values ​​of the percentage of infestation at the initial stage. However, they all repeat the trend of the monthly doubling of Varroa mites population with high accuracy !!! Family number 7 at the end of October is still alive, but its size is not very large. It occupies approximately 5-6 streets in the Dadant system hive. This family differs in that at the beginning of summer there was  formed one offshoot from it, consisting from 3 frames of brood, after that, when changed the queen, she did not lay eggs for about 1-2 weeks, then 2-3 frames of new brood were selected  one by one to increase offshoot. These operations led to the removal of part of the Varroa mites from the colony and to decrease of its general infestation. By the way, the offshoot died in september... Nevertheless, despite the deviation from the theoretical schedule, the trend of recent months still corresponds to a doubling of the tick population.

Thus, infestation of bee family by Varroa mites equial to 1-3%% , which seems insignificant, is not insignificant at all! If you will make an alcohol wash in April, and you will see such a degree of infestation, then according to the forecast, you will get an infestation of 8-24%% in July, which is already very difficult for a bee colony, and in September - 32-96%%, and this already lethal for any family of bees!

If you found infestation in the amount of 1-3%% in September, after the end of egg laying by the queen, then you can be sure that the family will overwinter well and actively begin spring development. But it will begin its development along with the population of Varroa mites, although they will decrease by 15-20% during the winter!

Thus, it can be argued that the best time for any treatment is April-May, the time of the greatest increase in the bee colony and the most active growth of the mites population. At this time, it is good to apply a complete removal of earliest sealed brood and treatment of adult bees with appropriate preparations which the beekeeper prefer most of all. It is especially important to do this in advance because at the end of May-June and before the first ten days of July in the middle lane, the free fall of mites on a sticky board almost completely stops, which, as a rule, causes a certain euphoria among beekeepers. They believe that the mites are gone and the family of bees is healthy. But it's not so! It's just till this time the mites that have overwintered in the family of bees are almost completely dying out, and the young mites of this season, born in March, April and May, are young and healthy and will not die off soon.

Thus, we consider absolutely fair (taking into account the acceptability for the beekeeper of the very fact of chemical treatment of bees from Varroa mites) the recommendation of American scientists to start processing bees from the moment, when percentage of infestation reaches 2-3%%. And do it immediately upon reaching values ​​of 3.5-5%%, because this is a critical value, with an increase of which the bee colony is already doomed to death. As we have already said, this is especially true for spring and early summer, when Varroa mites have several months ahead of them to intensively increase their population.

Emergency heating - the last opportunity to heat the nest.

It is well known to everyone that bees maintain the temperature with particular precision in the nest where the development of eggs and larvae takes place. The correct and stable temperature is very important in the transformation of larva into pupa, and pupa into bee. The conditions in which bees have to live in middle latitudes are not very comfortable for them. That is why, almost throughout the year, the bees have to heat their nest, and sometimes the entire hive. But this heating, which occurs under normal conditions of life of bee colony, usually consists of heating due to the release of metabolic heat by the bodies of bees and from heating due to the release of heat during the vibration of the thorax muscles of the bee. It's like a freezing man's shiver. A little muscle work contributes to the release of additional heat.

This type of heating is used by the bees in winter inside winter cluster, in the spring when heating brood, before swarming when heating the entire hive in order to provide the queen with a maximum suitable area for laying eggs, in summer when rearing brood and in autumn when heating the last brood and the bee cluster itself.

fig.1

But, there are situations in the life of bees when such heat is not enough. This is possible with a sharp cooling of the nest in spring or of a cluster of bees in winter, or  in summer, with a shortage of bees in offshoot to heat the queen cells. Then the bees use emergency heating.

Under acoustic control, this is the lowest frequency signal in the hive, presumably generated by bees vibrating not only with the muscles of thorax, but also with partially opened wings. This, it seems to us, is already not just alike shivering, when we are cold, but like clapping our hands and jumping or other more energy-intensive physical exercises that we do when we are very cold. Such movements allow bees to generate maximum heat without creating air movement in the nest. At the same time, energy losses require its replenishment, and therefore emergency heating signals (n1 fig. 1), as a rule, are accompanied by signals for in-hive works and works with honey (n2 fig. 1). What can be assumed if you see such a signal on the diagram of Apivox Smart Monitor ...

1. In summer and spring, there are too few bees in offshoot for calm heating of brood and queen cells. Especially queen cells.

2. You opened the hive in winter at low negative temperatures for about 5-10 minutes. The bees began to actively warm cluster in order  to restore an acceptable temperature in the crust of cluster.

3. If in winter and autumn, when the family of bees should be in winter cluster, you received such a diagnosis without opening the hive, then most likely there are very few bees left in the colony and the colony will soon die. As a rule, this happens when the family is severely affected by Varroa mites.

 

This is exactly what is shown in Figure 1. Having received such a diagnosis during acoustic control of the family from the upper part of the frames covered with textile, we saw two main signals - emergency heating and work with honey. Our assumption was that there are too few bees in the colony and they continuously eat honey and try to warm themselves. Visual control showed that  in the colony remained about 30-40 alive bees, which sat in a small lump on just one frame with honey, actively consumed it and tried to warm themselves. The colony died from being attacked by Varroa mites, showing an almost classic version of the Collapse of Bee Colonies - the hive is full of honey, and there are no bees or a few dozen left.

In any case, it can be said that appearance of such a signal is a sign of some kind of problem that requires the beekeeper to personally control the state of the family and, possibly, immediately help her.