We all know very well who the Varroa Destructor mite is and how beekeeping suffers from it. Therefore, we will skip all the preludes.
We set ourselves the task of finding a way to fight the mite without using chemicals and, if possible, even without using environmentally friendly preparations and zootechnical methods of fighting mites. Our work lasted for five years, and now we are finally ready to take a risk, saying that we have found a theoretical basis and a practical way to fight mites directly in the hive of an actively living bee family.
So, in order. At the beginning of our work there was a meta-analysis of the works of scientists from all over the world who conducted researches in different climatic zones of the earth, since in our opinion, in nature there is always a limiter to the expansion of any living creature.
The meta-analysis data showed that there are no problems with Varroa mites in the tropical zone of Africa, America, and Southeast Asia. They almost never reproduce in bee colonies and do not cause them any noticeable damage. But the colder the climate becomes, the stronger the negative impact of mites on bee colonies. And this is confirmed by dozens of works of scientists and data from practicing beekeepers. From this we concluded that it is the climate that is the basis for containing the reproduction of mites, and the main factors of it are humidity and temperature. And we began a meta-analysis of scientific works on bees, related to these factors. There were quite a lot of them.
The first factor that we studied and tried to use was humidity. The most complex and ambiguous. All scientific works say that mites stop reproducing at a relative humidity exceeding 80%. It would seem so simple! But it was simply in laboratory conditions, when specially prepared air was pumped into the hive. Our very first hives in which high humidity was created showed that in reality this is not the case.
Firstly, relative humidity is a parameter that depends on two variables - temperature and absolute humidity. And there is a rule, that with an increase in temperature, the relative humidity drops. So early in the morning we could get in the nest high humidity up to 70% for some time due to our evaporators, and then the sun raised the temperature in the hive, and during the day the relative humidity could drop up to 30%.
Secondly, the bees managed to actively resist our efforts by blocking convection in the hive. Active ventilation nullified our efforts. As a result, over three years and three modifications of our hive, the experimental families died from Varroa infestation and the accompanying viral infections.
The second factor we took on was temperature. The effect of temperature on Varroa mites is nothing new. There are a lot of patents and methods for treating bees, but none of them work except thermal chamber.
And the thermal chamber, like chemical preparations, has an efficiency of about 90%. Which means that there is a huge mass of mites in the bee colony from spring to summer. The thermal chamber usually knocks down over 5,000 mites from a good big colony. Our task was to suppress their development completely.
So, the next modifications of the hive combined the temperature factor and the humidity factor, but the results were sad again. Bee colonies died. Except for five experimental families in our second apiary. They went through the season without any treatments, there were almost no mites in the fall, and they felt great. The reason for this was not clear to us. But, we made our assumption and modified the hive again. The 2024 season showed that the modification was successful. And then the reason for this became clear.
It looked something like this - in April, we specially purchased two families treated with amitraz and formic acid from an amateur apiary. We placed one in a new hive, the other in a hive of the previous modification. We made an alcohol wash. It showed zero mites. In mid-May, we divided both families in half. In July, we again made washes from the first two families. Again, zero result in the experimental family. We decided to understand why. And we managed to do this.
Another meta-analysis turned out to be successful. It turns out that everyone, for some incomprehensible inertia, is trying to fight the mites themselves. These "tanks" in chitinous armor. And everyone unanimously complains that it is impossible to get all the mites, since 80% of them are always closed in the brood cells! As it turns out, this is the whole charm of the situation. It is in the sealed brood that they all end up as if in a locked cage, and are unable to get out of it!
We came across a paper that cleared it all up! And what a shame - it was Soviet and dated 1983! Two scientists - Akimov and Piletskaya, carried out the most important studies, the results of which, it seems, no one read or no one remember... They showed that the most vulnerable objects for impact are not the mites, but their eggs!
Exactly eggs start to die at any humidity in the hive and honeycombs, starting from a temperature of only 2-2.5 degrees Celsius higher than the optimum temperature for mites reproduction. Already at +36 degrees Celsius, up to 30% of mite eggs die, at +37 degrees Celsius, from 50 to 70% of mites eggs die, at +38 degrees Celsius die from 90 to 100%. And at a temperature above +38C, 100% of mite eggs die. That is why our new hive prevent the increase the mites population. A certain number of mites eggs from each egg laying constantly died in it.
This is why the attempt to briefly warming-up of the bees in the hive was ineffective - they transfer to the outer side of hive wall together with the mites sitting on them, and the mites do not die, even in the summer heat in Italy and Spain, when the wax combs melts in the hives.
The closest to us were the developers from Israel, they suggested to heat frames with brood to +43C for an hour 10 times per season. But, they forgot about the thermal inertia of frames with honeycombs and the corresponding duration of the necessary heating time to kill mites. An hour is very little even at this temperature.
So, what were the results of this sunny season of 2024...
The picture of temperatures and sunny days and our temperature measurements in experimental hive showed that many times during May, June and July, the temperatures in the hive reached the range of +36-37C, and on the hottest and sunniest summer days they reached +38-43C.
Moreover, this temperature was maintained in the hive for several hours. Young bees, naturally, got out of the hive and were sitting on the outer side of the hive's wall ! But the mites in the brood were forced to suffer and die!
And what about our bees and their brood? How they are? Oddly enough - excellent! All the horror stories about the death of bees and brood from such temperatures turned out to be greatly exaggerated. The bees developed perfectly, there were 6-8 frames of brood in a 10-frame Dadan hive.
The experimental family turned out to be no worse than the others in terms of honey yield. It produced 2.5 supers of marketable honey from white clover - the only mass honey plant in the apiary area. But, it should be clarified that at that moment it was without open brood after an offshoot with the old queen was made around May 15, and the new one was bred naturally.
The only downside, in quotes, was the accelerated development of the family and early entry into the swarming state, since there was little space in the 10-frame Dadan, despite the second body-box installed later.
We received the final results from three apiaries in the fall.
The first results gave our experimental apiary . Washing with 1% alkali (instead of soap or washing powder) gave such an indicative result. The experimental hive showed a mite infestation of 0.32%, when the other families in simple hives and hives of the previous version showed a mite infestation from 3% to 5.5%. Bee colony in experimental hive gave at least 10 times better results, than the best control colony!
At the second experimental apiary we obtained the following results.
In 2023, 5 families of Carnica bees in new hives survived the season and had practically no mite shedding in the fall. One of the families lived in a new hive for the 2023 and 2024 seasons, that is, almost 2 years without the use of any preparations. In September 2024, a comparative treatment of it and the control families of the apiary with Bipin was carried out. After treatment with Bipin (amitraz) the mites drop was about 200-250 mites in each control family. In the experimental family fell 3-5 mites. After this, additional treatment with formic acid was carried out by evaporating it. After a few days, 30-50 mites fell on sticky boards in control families, and in the experimental family there was no mites drop at all. The condition of the family is excellent.
Thus, we undertake to claim that we were able to create a hive model that allows suppressing the development of Varroa mites in bee families without any treatments or additional manipulations by the beekeeper. Varroa mites are still present, but with each season, if the requirements for keeping bees are met, there will be fewer and fewer of them until they are completely eliminated.
What should a beekeeper do for this... In order to keep bees in families that will have no or very few Varroa mites, it is necessary to follow simple rules:
1. The apiary should be located in the most open sunny place.
2. The hives should be oriented with the entrances strictly to the north-northeast.
3. Hives should be used that provide a temperature in the nest on sunny days of +36-38C, and on hot sunny days +38-43C.
4. Such hives should be populated with families that have been pre-treated against Varroa mites so that in the future the minimum mite infestation can be maintained in the families.
5. In the fall, the bees should be transferred to "cold wintering" as early as possible, so that the queens can quickly stop egg laying. Since in the fall the hive will work poorly due to the "colder" sun.
6. Despite these measures, it is necessary to periodically monitor the mite infestation using alcohol wash, at least once per season in the fall. If absolutely necessary, measures should be taken to further reduce the mite infestation.
Otherwise, the method of keeping bees does not change and remains entirely at the beekeeper’s discretion.
We are ready to discuss the prospects for commercial use of our development with all interested individuals and organizations.
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ReplyDeleteprespektiv ne luften kunder Varroas.