Wednesday, May 31, 2023

HOW TO PREDICT THE CRITICAL MOMENT IN THE GROWTH OF VARROA MITES POPULATION IN THE BEE FAMILY AND NOT TO MISS THE LAST POSSIBLE MOMENT OF ACARICIDAL TREATEMENT TO SAVE THE LIFE OF THE BEES.

All instructions for beekeepers issued by the Ministries of Agriculture of Europe and the USA, as well as European and American beekeepers' clubs, contain parameters of bee infestation at which it is desirable or necessary to treat bees with acaricidal preparations to save their lives.

But beekeepers, even amateur beekeepers who do not have many hives at all, do not want to spend time and efforts in order to assess the infestation of colonies using any of the methods known today. And today there are several such methods - using free fall of Varroa mites on a sticky board,  washing off  the mites using powdered sugar, and the most accurate one - alcohol wash.

All these methods of counting based on practical data are tied to the total number of mites in the bee colony. The number of mites in the colony and, accordingly, the percentage of Varroa mites in the colonies of bees indicate the need for acaricidal treatment and its urgency.

But, the big inconvenience of such recommendations is that they are not tied to specific months of beekeeping season. We fully agree with the recommendations of this table that when the infestation of worker bees is 4-6%%, urgent treatment with acaricidal preparations is needed, and when the infestation of worker bees is over 10%, it is already very difficult to save the colony, and this is a critical point, after which it is almost impossible to save the life of the family.

But how can we know when this moment of not return will come, at what deadline it is necessary to carry out acaricidal treatment in order not to lose the family of bees if at the moment the infestation is scanty? There is a fairly simple way to do this! All scientists who have studied the development of Varroa mites claim, and our practice confirms this, that the population of mites in the presence of brood in a bee colony doubles every month. Of course, there are some deviations, but in general this is exactly the case.

Knowing this and having carried out the most reliable alcohol wash of mites from worker bees (in the absence of alcohol, you can use a high-quality winter washer fluid for car windows), you need to build a graph that will predict the growth of Varroa mites population, starting from the infestation data obtained at the moment.

Let's give an example... Two families from our apiary... In two families - E4 and E6, alcohol wash was made and the results were obtained - 1 mite per 286 bees and 2 mites per 320 bees. The percentages of mites was, it would seem, ridiculous - 0.625%, and 0.356%! But Varroa mites  double their population, and hence the percentage of infestation every month! Let's have a look at the resulting graph:


It can be seen from the graph that if these families are not treated or no zootechnical measures are applied, then the infestation of one of the families will become critical in mid-September, of the second in mid-October, given that the measurements were taken in May. At the same time, it is clear that it is time to apply acaricidal preparations at least in August, so as not to bring the colonies of bees to death.

It's so simple! By making just one alcohol wash, you can determine the condition of your bees and the time they need acaricidal treatment.


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