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