Thursday, February 1, 2024

Link between hyperacidity and fungal infections in bee hives

 Author

Glebskij Serjio, Apivox Project

Key words 

Varroa mites, Aspergillosis, Ascopherosis, oxalic acid

Annotation

Ascopherosis, Aspergillus and other fungal diseases of bees and brood are not only difficult to cure diseases, but also have a high degree of danger to humans. The causes of the disease are usually simple, but not immediately visible. It turns out that this is largely the result of beekeeper mistakes. A combination of factors, such as improper operation of the hive, high humidity, lack of sufficient insolation and increased acidity in the hives due to the regular use of acid-based preparations, lead to the creation of conditions favorable for the growth of pathogenic fungi, which are always present in the hives as part of its natural microbiota. Thus, for an environmentally friendly fight against them, it is necessary to use such preventive methods as placing the apiary in a dry and sunny place so that the humidity is not excessive, and to the sun, if possible, which disinfects the hives and the ground around them, to using clean, young honeycombs in which there is no environment for fungal growth, to improve ventilation of hives during the main honey flow, to increase the temperature inside the hive, which will make it uncomfortable for fungal growth, to carry out preventive treatment of hives with alkaline preparations based on baking soda and soap solutions. All this will help to reduce the use of “heavy” chemicals to combat fungal bee diseases, and will help to prevent illness of people working with bees and of people using honey for food.

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https://scholarzest.com/index.php/ejare/article/view/4310

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Ascopherosis and aspergillosis are the two most common fungal diseases of brood and adult bees in beekeeping, which cause maximum problems for modern apiaries.

Ascopherosis, or calcareous brood, is a disease of bee brood that manifests itself in the spring-summer period and reaches its maximum development in June-July. The source of spores is considered to be nectar and pollen infected by them [1]. This is what determines the peak of infection development at the height of honey collection.

Aspergillus, or stone brood, is a fungal disease of brood, but also of adult bees. Pollen and nectar are also sources of infection. The fungus easily develops on honeycombs, bee bread, bee larvae, pupae and the bees themselves [1]. The fungus easily infects humans, and the disease is very severe and can lead to death.

It is proposed to fight an infection that has already appeared with rather heavy drugs, since in addition to the bees themselves, all the equipment and the apiary territory itself are infected. For radical treatment, it is recommended to use nystatin, actidione, choline salt of glucosylpolyfungin, thiabendazole, fungizone, unisan, griseofulvin and undecylic acid, a number of organic acids, in particular benzoic sorbic, sorbic monopotassium, acetic anhydride monosodium and others. It was also noted the possibility of using formic acid in high concentrations [1].

It is proposed to combat these diseases in the initial stage, as a rule, by destroying honeycombs with affected brood, by transplanting bee families into clean hives, by insulating and feeding, as well as moving apiaries to a drier place. In addition, it is proposed to use disinfectants such as Vetsan, formaldehyde solution, Percarb, hydrogen peroxide [1], there are also a number of pharmacological drugs.

It is known that spores of fungi, for example, the causative agent of ascopherosis, enter the hive with plant pollen. It is pollen that is the first place for the growth of these fungi in the hive [5]. In addition, the causative agent of aspergillus can also enter the hive from the ground if the hives are standing on it or on old rotting wooden stands, since rotting organic matter is the natural habitat of this fungus. But in order for fungi to grow in a hive, they require a number of conditions - certain humidity, temperature and acidity.

Humidity is an important condition for the growth of pathogenic fungi. For the causative agent of ascopherosis, this is 92.5% [1]. It is wet pollen collected by bees in rainy weather, or beebread damp in the hive, that become an ideal environment for the growth of fungi. Another reason for high humidity in the hive is the powerful honey flow and the great strength of the colony. With this combination, there is a lot of nectar in the hive, which the bees begin to evaporate, sometimes heating the air in the hive to +40C and sharply raising the air humidity due to the moisture removed from nectar. At such moments, humidity can reach exactly those values that are optimal for fungal growth [4]. The only way to reduce humidity in this case is increased ventilation, both forced - by bees, and natural - by opening all possible ventilation holes in the nest and in honey supers. But not everything is clear with the ventilation of hives. Active ventilation allows you to avoid moisture condensation and its penetration into the depths of the fungal habitat, but if ventilation does not remove excess heat and moisture from the substrate and does not cool the substrate on which fungi grow, then such ventilation can only activate the growth of pathogenic fungi [3].

Fungi that cause diseases in brood and bees belong to the group of thermotolerant fungi, for which optimal temperatures range is from +30C to +40C. For the causative agent of ascopherosis, the ideal temperature for growth and sporulation is +30-35C [1], and for the causative agent of aspergillosis - +30C [2]. This immediately calls into question the treatment of bees by insulating the hives. In the absence of other elements of influence, insulation can only worsen the situation. In addition, it is known that fungi prefer the warm season for growth - June-August [1]. Fungi can be affected by temperatures that are higher than optimal for their growth. Elevated temperatures will also affect the rate of decrease in humidity in the hive.

The acidity of the environment in which they grow is of utmost importance for the life of fungi (Fig. 1). For the causative agent of ascopherosis, the optimal acidity (pH) is close to neutral and is in the range between 7 and 7.5 [2].


But practice shows that this is a laboratory result and in real conditions in apiaries everything happens somewhat differently. This is evidenced by information coming from various sources about mass diseases of bees with fungal diseases after treating them with organic acids that are now so popular.

Oxalic and formic acids do have a suppressive effect on Varroa and Tropilaelaps mites, and they are organic in the sense that they are found in small doses in plants, insects and honey. However, a lot depends on concentration. Frequent and regular use of these acids leads to an increase in the acidic background in the hives and ultimately leads to the creation of optimal conditions for the growth of pathogenic fungi.

Observations of an eco-apiary in Sardinia of about 500 bee colonies showed the presence of fungal diseases. According to the eco-apiary status, Varroa mites can be controlled only with drugs approved for use in eco-apiaries, primarily oxalic acid. The search for the best ways to prevent and treat mycoses (Fig. 2) continues.



Fungal infections are also widespread in Georgia. One of the reasons is the spread of methods of treating bees with organic acids against Varroa mites instead of drugs amitraz and fluvalinate, which were used previously, but their effectiveness in the fight against mites has significantly decreased, and in addition, they were not recognized as environmentally acceptable.


Observations in 2021 showed that in April of this year, in samples of bees in apiaries where oxalic acid was used, pathological changes were detected in the digestive system of bees - black color of the intestines, similar to intoxication with honeydew honey, and there were also cases of violation of the integrity of the intestines of bees (Fig. 4).


And in May, in the same hives, ascospherosis in its classic form was diagnosed, with a characteristic lesion of brood (Fig. 5).


It should be noted that in both cases, apiaries are located in subtropical regions and in regions close to subtropical, with high summer temperatures, sometimes reaching +50C, and close to the sea the sea, which creates very high air humidity. In mountain valleys with rivers and streams, humidity is also high in summer. In total, all this is an additional factor that, in addition to increased acidity, contributes to the growth of pathogenic fungi in these two zones.

It is almost impossible to influence the microclimate conditions in a bees' nest. Bees need high temperature and humidity for normal brood rearing. However, other factors can be dealt with. General recommendations are to comply with the following conditions:

- To place the apiary in a dry and sunny place so that the humidity is not excessive, and the sun, if possible, disinfects the hives and the ground around them;

- To change honeycombs frequently;

- To improve ventilation during honey collection. (it is practiced to insert wedges between honey supers during the main honey flow in order to speed up the removal of moisture from honey);

- To increase the temperature inside the hive as a whole, making it uncomfortable for fungal growth;

- To maintain optimal acidity in the hive!

The last point is of great importance right now, when bee colonies are mainly treated with organic acids.

The issue of reducing acidity in hives goes very well with one of the most important methods of combating Varroa mites - the propagation of bees by broodless layering or swarms. When creating layers or after catching a swarm, the bees are placed in a box with mesh walls, through which they can be treated with oxalic acid by spraying or by trickling. In this case, the bees receive the normal treatment, but the acid will evaporate not in the hive, but in the open air, and the bees, after one or two days in a cool room, will be placed in a hive that will not be exposed to acid. A similar treatment can be carried out with bees hatched from the last autumn brood, collected into one or two powerful families. After all the bees have hatched, they are collected in mesh boxes, treated with oxalic acid by spraying or trickling, kept for a day in a cool room, and then combined with the main families which are going into the wintering.

In addition, for prevention, it is recommended to treat equipment, hives, frames (without honeycombs) with environmentally friendly alkaline preparations, such as soap and soda solution. This will neutralize acid residues in the hive and on the frames if they have been treated with acids. In any case, this will worsen conditions for the development of pathogenic fungi.

An important direction in the fight against mycoses may be the study of non-toxic and safe for humans substances that stabilize fungi and prevent them from growing. These are derivatives of propionic or methylacetic acid, known as the preservative E280. The food industry uses mainly derivatives of this substance - propionates E281, E282, E283. These additives are approved for use in some foods and cosmetics. They are used in medicine to treat mycoses, in eye drops, and in cough mixtures. Additives are allowed in the USA, Canada, Australia and European Union.

It is important to note that propionic acid has not only antimicrobial and fungicidal, but also insecticidal effects. It is believed that at a concentration of 0.5% by weight of the substrate it suppresses the vital activity of insects and mites, and at a concentration of 1% it destroys them [3]. It is possible that over time, the development of drugs based on food preservatives will be able to solve the problem of combating fungal infections in hives without loss of bees and the quality of bee products.

In conclusion, it can be saied, that eliminating the problem of acidification of bee hives in ecological apiaries, which arises due to frequent treatments of bees with natural acids, is an issue comparable in importance to the fight against Varroa mites. The solution to this problem must be sought in the same plane as the solution to the problem of varroatosis - in suppressing the development of diseases in a natural way - by creating conditions that are unacceptable for the life of both - Varroa mites and the pathogens of Aspergillosis and Ascopherosis.


Bibliography


  1. M.N. MUKMIN MYCOSES OF HONEY BEES. TREATMENT AND PREVENTION KAZAN FEDERAL UNIVERSITY INSTITUTE OF ECOLOGY AND NATURE MANAGEMENT Department of Applied Ecology Kazan - 2018 UDC 619:614:638.15 BBK 48.1

  2.  Zhukov Aslan Ahiedovich BIOLOGICAL PROPERTIES OF THE MUSHROOM ASCOSPHAERA APIS AND MEASURES TO COMBAT ASCOSPHEROSIS OF BEE dissertations for the degree of candidate of biological sciences Moscow - 1995

  3. LECTURE COURSE in the discipline: B1.V.DV.2.1 Mycology with mycotoxicology Federal State Budgetary Educational Institution of Higher Professional Education "KUBAN STATE AGRICULTURAL UNIVERSITY" Department of Microbiology, Epizootology and Virology

  4. Beekeeping courses at the Moscow State Academy of Veterinary Medicine and Biotechnology named after K.I. Scriabin. https://bee-keeper.ru/page/8-4-4-aspergillez-pchel

  5. Sainger, D. K., Garg, A. P., and Sharma, P. D. (1978). Mycoflora of some pollen grains. Acta Botanica Indica. Vol. 6, 165–168 Available at: https://scholar.google.com/scholar_lookup?title=Mycoflora+of+some+pollen+grains&author=Sainger%2C+D.K.&publication_year=1978 (Accessed March 1, 2022).










Sunday, December 17, 2023

RESEARCH OF MECHANISMS OF THE EFFECT OF OXALIC ACID ON THE BEES AND VARROA MITES.

 

Serjio Glebskij

Independent research project Apivox

Email - glebskij@gmail.com.

Key words - oxalic acid, Varroa mites, acoustic control

Annotation

Oxalic acid is a very effective active substance against Varroa mites if applied in the absence of brood and with sufficient humidity in the hive. It does not yet cause resistance in mites, but it also has a certain effect on bees [1]. But the mechanism of its effect has not been comprehensively tested.

There is scientific evidence that:

• The most effective is the use of 3.2-3.7%% oxalic acid, diluted in sugar syrup 1:1 [2].

• After treatment with oxalic acid, the temperature in the hive increases, even in the autumn broodless period, to temperatures of +33C-42C [3].

• The use of oxalic acid can provoke the start of oviposition by the queen, despite the late autumn time.

• Oxalic acid acts on Varroa mites even without contact with them [4].

 

Our experiments have shown that there is a direct relationship between rising temperatures and the number and speed of mite shedding. Only where there is a rise in temperature above +30C, a significant fall of mites occur already in the first days. Acoustic monitoring of the state of bees using Apivox Smart Monitor showed that the initial rise in temperature in the hive occurs due to the active work that bees do working by their wings. Under different conditions, vibro-acoustic signals were recorded at a frequency of 125 Hz, with the 1st and 2nd harmonics, and vibro-acoustic signals at a main frequency of 250 Hz with secondary peaks at frequencies of 125 Hz and 375 Hz.

This shows that mite shedding is the result of a complex of actions.

• Death from the direct effect of the acid itself and its vapors on Varroa mites.

• Fall of the mites due to the high temperature to which bees heat up when working with their wings.

• Fall of the mites due to mechanical vibration created by bees at high speed of flapping their wings

• Death of the mites due to the fact that oxalic acid has an indirect effect on mites through the hemolymph and fat body of the bee, which partially metabolizes oxalic acid, and which in this way enters the body of mites [6].

All together creates a set of conditions for the death and subsequent fall of Varroa mites when bees are treated with oxalic acid.

Introduction

There are several ways to treat bees with oxalic acid - spraying with an aqueous solution of acid, drip treatment with a solution of acid in glycerin, drip treatment with a solution of acid in sugar syrup and sublimation. The best overall efficiency and safety indicators are for a 3% solution of oxalic acid in sugar syrup 1:1. But what happens during the processing? What is the cause of mites fall? It is believed that oxalic acid produces a contact effect. At the same time, the effect of sugar-free solutions and sublimation is less effective and lasts for less time. It is possible that sugar and glycerin adsorb moisture from the air, and this is the reason for their effectiveness. The aqueous solution directly supplies some water, which, however, quickly evaporates, after which the acid can only act if the hive is sufficiently humid. And this has been confirmed experimentally [1].

On the other hand, there is scientific evidence that the death of mites also occurs in the closed volume of a laboratory capsule in which mites and drops of corresponding liquid containing oxalic acid are placed [4]. The same trend is observed. The best effect is obtained from a solution of oxalic acid in glycerin and then in sugar syrup. Thus, it can be argued that oxalic acid produces not only a contact effect on Varroa mites, but also a general poisoning effect.

But this is not the only way oxalic acid enters the body of mites. This is confirmed by scientific data [5]. A preparation of oxalic acid, labeled with radionuclides, was introduced into the bee colony using the usual method - that is, drip. As a result, after some time, radionuclides from a solution of oxalic acid were discovered in the body of bees and their hemolymph. Radionuclides were detected in 8-9 day old brood. Radioactive markers were also found in the wax of freshly built honeycombs and in fresh honey. At the same time, the maximum infestation of bees was during the first 4 days after using the drug. According to scientists, this may mean that the results of the experiment are consistent with the hypothesis of the metabolism of oxalic acid carried out by bees. Thus, oxalic acid can act on mites in the same way through feeding on adult bees and even brood, leading to their death.

But what happens to the bees in the hive after they are treated with oxalic acid? We conducted an experiment with four families of different strengths.

Materials and methods

For the experiment, we used four families of third-generation Buckfast bees. Two families were quite strong, each occupying a full hive of Dadan - No. 4 and No. 5, one occupied about 2 frames - No. 6, and the other 5-6 frames - No. 3. The volume of the hives of all four  colonies was not reduced. (Figure 1).

Figure 1 - hives of the families participating in the experiment


All families were left without any treatment throughout the entire spring-summer season of 2023. Since April, mite control was carried out in them, which by September 19 amounted to the following values: No. 3 - 2.5%, No. 4 - 19%, No. 5 - 14.4%, No. 6 - 14.5%. The remaining sealed brood available on September 19 was removed. For processing, dehydrated oxalic acid was used, which was diluted to a concentration of 3% in sugar syrup with a concentration of 1:1. The treatment was carried out dropwise, at the rate of 5-6 milliliters of the composition for each frame occupied by bees. To monitor the effectiveness of the treatment, observation of mites falling onto a sticky board was used. After treatment, the temperature in the hives was measured using digital thermometers with a remote sensor placed between the frames occupied by bees, in the center of the hive at a height of approximately the middle of the frame. Acoustic monitoring was carried out using the Apivox Smart Monitor device (apivox-smart-monitor.weebly.com).

Results

The first treatment was carried out with oxalic acid, diluted to a concentration of 2.5% in sugar syrup with a 1:1 consistency. After 4 hours, hardware control began, which gave the following results (Figure 2). As a result, in hives No. 4 and No. 5 powerful signals were recorded in the range of 240-260 Hz, significantly exceeding all other sounds in the hive, which was indicated by the red color of the graph in the upper half of the screen. Moreover, it was in these hives that a significant rise in temperature was observed to +33.3C in hive No. 4 and to +34.3C in hive No. 5. In hive No. 6 (about 2 frames of bees), no significant sound signal was observed in the specified range, and the observed temperature was +30.2C. In hive No. 3 (about 5 frames of bees), the signal in the specified audio range was also weak. At the same time, the temperature between the frames with sensor did not exceed +24.5C.

Figure 2 - results of acoustic and temperature control

Five days after treating the colonies with oxalic acid, all hives were inspected. Firstly, due to the presence of a signal in the frequency range 240-260 Hz, which corresponds to signals associated, in our opinion, with the care on open brood (aeration, heating), we monitored the frames between which sensors were installed in hives No. 4 and No. 5. It turned out that in both hives the sensors were located between the frames with honey, and there was no brood. This means that the sound signals only coincided in range with the signals of caring for open brood, but the task and reason for the work performed by the bees was completely different. The sticky boards were also checked for the presence of mites that died after treatment. The result coincided with the distribution of temperatures and sound signals recorded on the day of treatment. In hives No. 4 and No. 5, the shedding was quite significant, and according to estimates, it was 600-800 mites in each hive. About 10-15 mites fell in hive No. 3 and 2-3 mites fell in hive No. 6. On the same day, colonies in hives No. 3 and No. 6 in which practically no mites fall was observed were re-treated. We once again recorded the reaction of bees to oxalic acid, diluted in sugar syrup, and introduced dropwise into the colonies, using Apivox Smart Monitor acoustic control device (Figure 3).

Figure 3 is the result of acoustic control of experimental colonies

The figure shows that the family in hive No. 3 responded to the treatment with the appearance of a sound signal in the range of 240-260 Hz at 17-52, and by 19-21 this signal became predominant in the hive. Hives No. 4 and No. 5 were not treated again, but by the evening they also had sound signals in the specified frequency range, which most likely indicates the continued effect of oxalic acid on bees. Hive No. 6 again did not respond to repeated treatment with the appearance of a specific sound signal. After another six days, another personal control of all hives that were treated with oxalic acid was carried out. During the control, the maximum fall of mites was again recorded in hives No. 4 and No. 5. This time quite a lot of mites fell in hive No. 6. Acoustic monitoring showed that the process of exposure to oxalic acid on bees continued. In addition, the presence of nest heating signals could indicate preparation for brood rearing. After another three days, repeated control of mites drop on the sticky board was carried out. An examination showed that in hive No. 3  fell only a few mites; in hive No. 4 and No. 5 it was quite large, but we are talking about several dozen. The next control was carried out after another 10 days. Monitoring the mites drop on the sticky board showed that the fall continues at approximately the same rate as before. An examination of the families showed the presence of brood in the weakest families No. 3 and No. 6. This brood was completely unexpected, since all the frames with the sealed brood had previously been destroyed. This may mean that this is a new brood that appeared in the period after the first treatment of colonies with oxalic acid around September 20, in the presence of positive outside temperatures.

It should be added that we observed a similar reaction in families in another apiary in mid-November at positive external temperatures (Figure 4).

Figure 4 - brood in mid-November after treatment with oxalic acid

The next control of families was carried out after another 10 days. The mites drop was approximately the same as the previous time - several dozen mites in hives No. 4 and No. 5, and a single mites in hives No. 3 and No. 6. In hives No. 4 and No. 5, repeated treatment was carried out with 3% oxalic acid with sugar syrup. After 16 days, the mites drop was amounted to about 1000 mites in E4, about 600-800 in E5. This roughly corresponds to the difference in the percentage of mites infestation of these families. On average, during a month of experiments, from 57 to 75% of mites fell off. But this is very approximate.

(VERY IMPORTANT: In real beekeeping practice, repeated treatments cannot be carried out due to the subsequent significant loss of bees! Colonies, after repeated treatment, are greatly weakened until their complete death (Figure 5).

Figure 5 - bees that died after repeated treatment of the colony with oxalic acid

As a rule, treatments of the same bees are not carried out. Overwintering colonies of bees are processed in winter or late autumn at temperatures from -5C to +5C, in the absence of brood and the streets densely filled with bees. Layers and swarms are processed in spring;  in summer, colonies are processed with queens blocked in the isolator and the brood completely released. But, in any of these cases, bees are always processed that have never been processed before in their lives.) 

Acoustic control of these families showed that family No. 4 again responded very actively to the treatment, generating sound signals in the range of 240-260 Hz. (Figure 6).

Figure 6 – results of acoustic control of families No. 4 and No. 5

At the same time, it was noted during observation in the Monitoring mode, that the signals in the region of 240-260 Hz. had a characteristic appearance, indicating that the frequency in the range of 240-260Hz. was the main frequency of the signal emitted by the bees (Figure 7).

Figure 7 - spectrum of bees sounds during acoustic control of colony No. 4


Discussion

The results of the experiment confirmed that the method of treatment with oxalic acid diluted in sugar syrup turned out to be quite effective and efficient. Inspection of sticky boards in experimental hives confirmed that maximum mites drop occurs in the first 5-6 days. This is consistent with the results of scientific studies, which say that it is during this time fall up to 90% of the total number of mites that will die as a result of treatment. (Figure 8)

Figure 8 - graph of mites fall after treatment with oxalic acid in different variants. From work [1].

It is true that with such a treatment the temperature in the hives actually rises quite strongly, up to +35-42C (Figure 9). In our case, in strong families, we recorded temperatures up to +34.3C.

Figure 9 - graph of temperature changes in hives of families treated with oxalic acid. From work [3].

In addition, in this experiment, a completely new and previously unknown fact was fixated - the reaction of bee families to treatment with oxalic acid, in the form of the appearance of a certain characteristic sound and at the same time a fairly strong rise in temperature. In full-fledged families which occupied a full hive, was fixated an intermittent sound at the main frequency of 240-260 Hz., which was found out thanks to specific spectrum diagram (Figure 10).

Figure 10 - graph of the spectrum of a pulse sequence filled with a carrier frequency and the spectrum of acoustic signals in full-fledged colonies of bees of the apiary, after treatment with oxalic acid.

The same sounds with the same spectrum figure are observed before swarming and when the queen is lost. We consider these sounds to be signs of "open brood care." This sound is emitted by the bees on combs with brood, periodically opening their wings and making sounds with them for a fairly short interval of time. These sounds are repeated by different bees at irregular intervals (Figure 11). As a result, an intermittent signal with a specific spectrum pattern appears.

Figure 11 - The bee on comb with brood actively flapping her wings

We believe that a possible reason for the appearance of such a signal when bees are treated with oxalic acid is the possible similarity of the smell of oxalic acid and the smell of open brood. It is known from scientific works that open brood secretes several types of acids [6]. In particular, the larvae of worker bees secrete acids - isobutanoic, isovaleric, nonanoic, fumaric, benzoic, phenylacetic, myristic, suberic and azelaic. This could explain the reason why bees perform actions similar to aerating and warming of open brood. In this case, the bees, starting to work with their wings, raise temperature so much that conditions favorable for the laying of eggs by the queen are created. It is this effect that leads to what beekeepers who use oxalic acid for autumn treatments talk about - to the beginning of egg laying by  queens at the most inappropriate autumn and winter time! A completely different situation develops in weak colonies that are in a full hive and are not separated from the main volume of the hive by an insulating partition. Such colonies, as we saw in our experiment, are not able to raise the temperature in all hive. But they can make this between two frames. We saw that the smallest families were the first to rear brood after treatment. At the same time, we also observed that the effect of acid on Varroa mites was significantly weaker in such families. The mites drop was also significantly smaller.

An additional factor in the effect of oxalic acid on mites could be its metabolization by bees. It is possible that part of the sweet liquid with acid falls on the bees during processing and, voluntarily or involuntarily, enters their body when they are cleansed of it, because according to the instructions, you need to drip syrup with acid specifically on the bees between the frames. Once on the bees and, possibly, in their food tract, oxalic acid enters their hemolymph and fat body, which the mites feed on. Thus, the acid not only has a contact effect on Varroa mites, but also directly enters their body, weakening or killing them. And such a factor may be the reason for the long fall of mites after exposure to oxalic acid. After all, as we showed earlier, mite fall can occur quite actively up to three weeks after treatment.

At the same time, the hard work performed by the bees with their wings is sometimes sufficient to raise the temperature in the hive to +40-43C. It can be assumed that the body temperature of the bees themselves can reach higher values. At the same time, it is well known that at a temperature of +38-40C, female Varroa mites do not lay eggs, and temperatures from +40C to +45°C with an hour’s exposure practically make Varroa females incapable of laying eggs. This may well be an additional factor in the effectiveness of treatment with oxalic acid. Some mites fall off under the influence of temperature, vibration and contact with acid. Some mites receive an additional dose of acid through feeding on the bees, and gradually they will die and fall off, although not so quickly. And, perhaps, there will be another group of mites in the family that did not fall on the sticky board, but survived and remained to spend winter on the bees, but at the same time lost the opportunity for spring reproduction. This may be one of the most important factors in the effect of oxalic acid on Varroa mites.

Conclusion

Thus, we can say that the result of treating bees with oxalic acid is a combination of factors that have a detrimental effect on Varroa mites. Namely:

• Contact effect of oxalic acid on bees and mites.

• Vibration from the active work of bees with their wings as a result of exposure to oxalic acid, leading to better shedding of mites.

• A sharp rise in the bees' body temperature, leading to the activation of mites, their movement throughout the bee's body, and better abscission.

• A sharp rise in temperature to values above +40C, leading to partial sterilization of female mites, which do not fall off after treatment, but lose their ability to reproduce in spring.

• Additional effects of acid on mites through the hemolymph and fat body of bees.

• General toxic effect on mites through breathing acid vapors. (Including the same effect, although to a lesser extent, on bees.)

Bibliography

1.  Bee tolerance of different winter Varroa treatments. Jean-Daniel Charriere,   

     Anton Imdorf, Rolf Kuhn Agroscope Liebefeld-Posieux, Swiss Bee Research

     Centre, CH- 3003 Berne Switzerland

2.  Oxalic acid treatment by trickling against Varroa destructor: recommendations

     for use in central  Europe and under temperate climate conditions JEAN-

     DANIEL CHARRIÈRE ANDANTON IMDORF

3.  Apicoltura Lugano, Federazione Ticinese di apicoltura - sezione Luganese, 

      Le api e l’acido ossalico. Daniele Besomi

4.  Activity of oxalic and citric acids on the mite Varroa destructor in laboratory

     assays. Norberto MILANI* Dipartimento di Biologia applicata alla Difesa

     delle Piante, Udine University, Via delle Scienze, 208 – 33100 Udine, Italy

5.   PHARMACODYNAMICS OF OXALIC ACID IN THE HONEY BEE

      COLONY A. NANETTI 3 BARTOLOMEI 1 Stefania BELLATO-2 Maria

      De SALVIO- GATTA VECCHIA-2  GHINI-2 . 1-E.N.E.A. – U.F.I.S. sede di

      Montecuccolino, Bologna, ITALY,  2-U.C.I. Scienze Chimiche 

      Radiochimiche e Metallurgiche, Facoltà di Farmacia, Università di Bologna,

      ITALY.

6.   SYNTHETIC PHEROMONE PREPARATIONS IN BEEKEEPING. K. A.

      Tambovtsev, M. P. Yakovleva, N. M. Ishmuratova.



















Saturday, November 4, 2023

Control of 4 colonies in cold autumn weather using Apivox Smart Monitor

 Cold weather is not a problem for the device Apivox Smart Monitor. It can easily help you find out the status of your bee colonies without opening the nest in the cold and without disturbing of wintering bees.



Sunday, October 22, 2023

An excellent result of Apivox Varroa Eliminator project - new project for environmentally friendly control of Varroa mites.

 I can't help but share some encouraging information. Today we managed to make alcohol washes from SIX experimental families that were in hives of a new design (3rd modification) for the second year without any treatment during this year. The results of mites infestation at the end of October ranged from 1% to 5%. This is an excellent result! After the last brood comes out, we apply jet (or it is also called trickling) treatment with oxalic acid diluted in sugar syrup. And I think that by spring families will arrive with 1-2% mite infestation, and spring treatment will reduce this percentage. This is all especially gratifying against the backdrop of SIX control families that were also not treated during this season. As of today, only TWO of them have survived, and it is not yet clear whether they will survive until winter. The rain prevented me from finishing the wash. But we'll check it out. So the effect of using a new hive (using 12 families in the experiment) is clearly positive. Besides! During sampling, a visual inspection of the bees in the colonies was, naturally, carried out. The result of the observation is that in the experimental colonies there were NO bees with deformed wings. In families that underwent spring treatment with “heavy” chemicals and a couple of acid treatments, but lived in ordinary hives, such bees are observed on the honeycombs. What is especially valuable about these observations is that all this was done by a professional beekeeper and queen breeder, and not an amateur! And his conclusion about the results of using the hive is very positive. He called it the “lazy hive” because he climbed into it only 4 times during the entire season. And at the same time, he took a couple of Dadant body-boxes of honey. And till now the bees are alive and well. So this is our first practical success. In addition, a training course on “sustainable beekeeping in a lazy hive” will be completed soon. It remains to make drawings of a new model of the hive, since the previous ones are outdated. In addition, we have technology specially developed for the Mediterranean climate.

 

Do you have a desire to join our project? ;)))  We will be glad to participants as much as to any support and assistance!




Saturday, October 14, 2023

The response of bee colonies to the installation of frames with partially opened honey from the point of view of acoustic control.

Setting up food frames during the autumn fall season naturally activates the bees. But how does this happen and how does it affect the diagnostics of the Apivox Smart Monitor device. Now you can see it quite clearly.

In the figure you see two stages of diagnostics of two families that were in approximately the same situation - there was not enough food left.

Before installing frames with last year's honey, diagnostics were carried out in the General State Control mode. In both cases we see that in-hive works (1) of greater or lesser force takes place. In family No. 1, in which there are much fewer bees than in No. 2, there are visible two signals: a signal of emergency heating (4) and of active heating (5). The fact is that the hives do not have top insulation. Essentially the bees are on open air. The heat is not retained in any way. This is the reason for the heating signals.

After frames with honey were placed in the families, and some time passed, we see a sharp change in the picture. A powerful signal of work on honey collection appeared (2). That is, bees develop honey reserves, transport and process honey. In Readiness for Honey Harvest mode, we also see confirmation of their work - the graphs are white and are located mostly at the bottom of the screen (3), which indicates active work on collecting honey and moving it closer to the nest. Most of the active bees took up this work. Precisely the majority, since all our readings are relative and always speak not about all the works in the hive, but about the most active ones, the sounds of which rise above the general background of the hive.







Monday, October 2, 2023

How to carry out control if there is no canvas and insulation over the frames

Many beekeepers now use transparent plastic canvas instead of the usual canvases and pillows. Under normal conditions, it is impossible to carry out monitoring using Apivox Smart Monitor device if there is no opaque canvas. The light falling on the bees excites them and the sound background of the hive changes dramatically. Here is a technique on how to do this to get reliable results. Just remember that you need to minimize any extraneous sounds in any way. Including your own speech!!!!




Wednesday, September 20, 2023

Conducting of acoustic control of two bee colonies due to temperature sensors readings in order to confirm the start of egg laying by the queens.

 During an external examination of the experimental hives, it was noticed that in the two strongest families the temperature in the nest was significantly higher than 30 degrees Celsius. This was puzzling, since the week before, all remaining brood had been removed and all insulation had been removed in order to ensure a smooth transition for the bees to cold wintering. But the weather is too warm for the end of September. Despite the cool nights, during the day it warms up to +20C and above. We decided to conduct an acoustic control in the evening to check for the presence of open brood, since we did not observe any sealed brood during the inspection.



The check shows that the bees' signals correspond to the presence of a sufficiently large amount of open brood in these two families.


Thursday, August 31, 2023

RESULTS OF THE EXPERIMENT ON THE ANALYSIS OF RESPONSE OF BEEES TO THE SHARP COOLING OF THE NEST.

 The results of our observations, which form the basis of the operation of the Apivox Smart Monitor device, show that there are three types of nest heating by bees:

1. Passive heating due to the heat generated by the body of the bee in the course of normal life

2. Active heating of the nest by generating heat using high-frequency tremor of wings and thorax

3. Emergency heating of the nest due to the generation of a large amount of heat thanks to the active low-frequency flapping of half-opened wings of the bees.


The second and third methods of heating the nest create certain sounds that the Apivox Smart Monitor picks up, which is reflected in its diagnostics or in the diagram. We decided to once again confirm our data and look at the reaction of bee colonies of different strengths to a sharp cooling of the nest. To do this, we used the moment of transition of the experimental apiary to preparation for cold wintering. The task of this process is to stop the laying of eggs by the queen due to the deterioration of the temperature conditions for this in the hive.


To cool the nests and to switch bee families to cold wintering, the hives were opened for about 30-40 minutes in the evening cold of the end of summer (+14-16C). To do this, roofs and insulation were removed and open beehives were left. The photo shows gratings that do not allow the bees to fly out of the hive, but do not interfere with the passage of air and sounds. All the bees immediately went inside the "streets" betwee frames.

    After that, acoustic control of all families was carried out.


Family E3 - offshoot with a large number of bees and a small amount of remaining brood. After opening the hive, we see the appearance of an excitation signal (1) and a small peak in the area of ​​emergency heating signals (2). Active heating of moderate strength, not much more than usual (3) . After 10 minutes, the heating weakens somewhat, the bees calm down. The family can warm itself due to the large number of bees, so the reaction is quite calm.

The E4 colony is a very strong colony with 6-7 sealed brood frames. There is not much young brood, but it is. We see that the family needed to start emergency heating (4) despite the large number of bees. In addition, at the very beginning, the bees actively began heating and caring for open brood (5).

The E6 family is a weak layer on 6 frames, separated by heaters on the sides. There are not many bees. There is practically no brood. The reaction to cooling is very violent. There is a very strong emergency heating signal (9), which subsides after ten minutes and there is a strong active heating signal (10), such as we can often see in winter.

Thus, the results of the experiment once again confirmed the presence of the reaction of bees to a sharp cooling of the nest, which is a sequence of the following actions: at the beginning, an emergency heating of the nest appears, then turning into a less energy-intensive mode of active heating. At the same time, the strength and time of the appearance of these works and the signals corresponding to them depend on the state and strength of the colony, the size of the hive, and the presence of both types of brood.

 The app -  apivox-smart-monitor.weebly.com






Wednesday, August 23, 2023

PECULIARITIES OF DEVELOPMENT OF VARROA MITES POPULATION IN HONEYBEE FAMILIES, POPULATION GROWTH CONTROL USING THE METHOD OF TWO GRAPHS, AND ZOOTECHNICAL METHODS ALLOWING TO REDUCE THE SIZE OF VARROA MITES POPULATION.

Annotation 

The continuing growth of losses of bee colonies from factors that are based on the infection of bee colonies with Varroa mites forces us to look for new or well-forgotten old methods of dealing with them. But no fight is possible if you don't know your opponent well. In the course of theoretical research and practical experiments for over four years, we managed to understand the peculiarities of development of Varroa mites population in honey bee colonies, to create a method for controlling the development of the mite population and to outline additional ways to combat this parasite which destroy a huge number of bees around the world. For monitoring of the development of Varroa mites population we developed our own method on the basis of counting of Varroa mites falling free of on a sticky board.  This method is based on the monitoring of two different types of falling mites - old females and young female mites that did not take part in the reproduction. This made it possible not only to understand the main cycles of reproduction of Varroa mites in bee colonies, but also to propose simple and absolutely harmless zootechnical methods for suppressing their development, such as cold wintering, suppression of the swarming state, removal of the earliest and latest sealed brood of worker bees. And all this with a precise understanding of those key points when each of these impacts will be most effective.

Key words

 Varroa mites, varroatosis, bee diseases


Introduction

Studying the materials published in the American Bee Journal # 4 2020, we came across statistics, which fully correspond to our own results obtained during the work on the Apivox Varroa Eliminator project. This both pleased and upset us, since the loss of bees wherever they occur, worsens the situation with the bees on the entire Earth.

In addition, the statistics again confirmed, that none of the drugs currently used in beekeeping, no matter how loudly they are advertised, do not radically solve the problem of combating varroatosis in our apiaries, but only put us "on the needle" of companies that produce heaps of "highly effective drugs" for the treatment of bees from various diseases! 

Let's move on to specific data and their interpretation ...

 So, the first material is data on the loss of bees over the past 10 years according to Bee Informed organization (Fig1).

The graph shows, that in the US, average bee losses have increased from 25-30 %% to 35-40% per year. Professional beekeepers always say that these are exaggerated figures that have nothing to do with reality. But, this is not entirely true.

The graph shows, that in the US, average bee losses have increased from 25-30 %% to 35-40% per year. Professional beekeepers always say that these are exaggerated figures that have nothing to do with reality. But, this is not entirely true.

Professionals also have bee losses, but they are significantly less than those of amateurs and beekeepers with small apiaries (Fig2, Fig3). We also agree with this. The reason, as a rule, is that amateurs are trying to conduct eco-friendly beekeeping and to use as little as possible chemicals intended to treat bees from various diseases. At a minimum, they use them in the event of illness of their bees. 


Professional beekeepers are always trying to act ahead of the curve, as are poultry and livestock breeders. Why wait for the animals to get sick? This always results in waste of time and money. All measures for the treatment or, more precisely, for the prevention of diseases are carried out within clearly defined terms, regardless of the presence or absence of a real disease. Therefore, diseases occur less frequently and the losses from them are less. If the main task of the apiary is pollination or rearing queens, then the amount of chemicals in the combs and honey does not matter at all for them.

But, as it can be seen from the graphs, the losses of bees both in professional beekeepers and in other beekeepers, have been growing in recent years proportionally despite some difference in absolute values !!!!


In addition to these data, there is a table, which became the result of a survey of beekeepers about the reasons for the death of bees in their apiaries. The result was expected - most of the bees died from infestation with the Varroa mites! I think that the column "weak in fall" can be safely summed up with the column "died from the Varroa mites" ... Our studies, which we told you about, claim, that this is most likely the result of an autumn peak in the development of the population of Varroa mites, which many beekeepers do not notice during and after Main honey harvest. So, we believe that 69% of the deaths of the bees in small apiaries occurs from infestation with Varroa mites, which today cannot be completely destroyed by any means!  What does all this say... It says that despite the advertising-oriented results of "successful use" of various oils and chemicals, they are not very effective in real life! To quote from an American Bee Journal article ... "  Four chemical control options show the greatest potential for better survival in survey results for the past four seasons. Essential oils Apiguard and ApiLifeVar show about a 30% greater survival, and use of Apivar about a 29% better survival. Oxalic acid vaporization demonstrated an 11% better survival over the past three years, but survival improvement of Oxalic acid drizzle was minor and in only one of the last three seasons…"  But, if we look at Fig. 1, we will see that there is absence not only of increase in survival, but, on the contrary, from year to year there is an increase in the death of bees.

That is why we believe that it is important to understand the vital processes in Varroa mites going on in bee colonies, to be able to control them and be able to suppress this development not only with chemical preparations, but also with simple zootechnical means that you need to know and be able to apply. Ideally, we believe that it is necessary to achieve such coexistence of bees and Varroa mites, in which their presence in bee colonies will cease to be lethal for the latter.

 

Materials and methods

There are several methods for obtaining data on the infestation of a colony of bees, of which the most radical is an alcohol wash, and the most gentle is the control of the mites drop on a sticky board. There were a lot of attempts in order to adapt a mites drop for analyzing the degree of infestation of bee colonies, but everyone wanted to get specific numerical data, even if this required adjusting the numbers to the result. On the basis of this method, there were built some methods which were distributed by the ministries of agriculture of the USA, Britain, Spain and other countries (Fig. 5).

Based on the average number of mites falling on sticky board per day, it is proposed to build a method for treating bees with acaricidal preparations. Representatives of the agricultural industry, trusting scientists, recommend this method for assessing the infestation of bee colonies as the least laborious. It is believed that it gives fairly accurate results. But sometimes it's not quite like that, and sometimes it's not like that at all. In various scientific works of scientists who studied and evaluated the accuracy of all known methods for calculating infestation, it is written that all methods are equally inaccurate at the very beginning , when the number of mites in the family is small, and at the end of the season, and that in these works scientists use at least three different coefficients for converting the number of daily falling mites to the total number of mites exists in the bee colony. We know that there is a coefficient by which the average daily tick talus is multiplied equal to:

1)   20 in spring, and to 40 in summer and  to  250-500 during broodless  season.  Fig.6 ( Population model for the ectoparasitic mite Varroa jacobsoni in honey bee (Apis mellifera) colonies Stephen Martin  National Bee Unit, Central Science Laboratory, Sand Hutton, York, YO4 1LZ, UK )

2) 120 throughout the season.  Fig.7 (Development of the mite, Varroa jacobsoni oud., in the honeybee, Apis mellifera L., in Michigan, USA, and a comparison of diagnostic methods for detection of the mites Ahmad Al Ghamdi and Roger Hoopingarner )

3)  170-200 throughout the season.  Fig.8  (GUÍA TÉCNICA PARA PARA LA LUCHA Y CONTROL DE LA VARROOSIS Y USO RESPONSABLE DE MEDICAMENTOS VETERINARIOS CONTRA LA VARROA   DIRECCIÓN GENERAL DE SANIDAD DE LA PRODUCCIÓN AGRARIA  SUBDIRECCIÓN GENERAL DE SANIDAD E HIGIENE ANIMAL Y TRAZABILIDAD)

This already suggests that each researcher adjusted the coefficient to the situation in his apiary, or in his zone.  And even this fitting  does not work if used in mathematical models, which are compared then, with the real results of counting of Varroa mites in bees... Fig.9 (Population growth of Varroa destructor (Acari: Varroidae) in honey bee colonies is affected by the number of foragers with mites Gloria DeGrandi-Hoffman  Fabiana Ahumada Victor Zazueta Mona Chambers  Geoffrey Hidalgo Emily Watkins deJong)

For our project we invented our own method of calculating mites drop. It consists in a separate count of dark - old, already participated in reproduction females, and pale-colored young female mites and deutonymphs, which died or were not fertilized by a male mite inside the cells, and were thrown out by the bees. Fig.10.  We call this the two-graph method. So, what is its meaning ...

The point is that in addition to the fall of old dark mites, that is clearly visible to everyone, there is another process - the process of death of young females that have not yet participated in the growth of the mite's population. Pay attention to the photo Fig.10. It shows the mites, which fell down on sticky board of our experimental hive in different seasons of the year. They all have a different color !!!  Mature old fertilized females are deep red and burgundy! Young females have a bright red color that is darker or lighter depending on maturity, and the paler ones are not mature females and transparent individuals are deutonymphs ...

So, the method of two graphs that we use involves separate accounting of old female mites - the blue graph, dying during or after breeding, and young females that did not participate in reproduction - the red graph. By shifting back the blue graph of the fall of mature dark mites by 2.5-3 months, or the approximate life span of the mites, we can talk about the approximate time of their birth, and we can analyze the events that led to their appearance in the bee colony. The appearance of fall of pale mites, according to our long-term observations, is a very bad sign, and indicates an over-intensive reproduction of Varroa mites, when it uses for reproduction all the brood zones that are not even very suitable for reproduction in terms of climatic parameters. Thus, using two graphs (Fig. 11), we can learn about the past of the mites population from the blue graph, about the prospects for its increase in the future, and about the intensity of its growth process at the moment according to the red graph. 

In general, the mites drop by itself at the time of control is not always indicative. There are intervals, as we can see from the graphs, when there is practically no fall of the mites or it is very small. This does not mean that there are no mites or that its number is small. It's just that the mites are waiting for the right conditions for mass reproduction, or they're just all young and healthy. From the graphs, we see that the mass death of Varroa mites of all ages is directly related to the cycles of enhanced reproduction, which, apparently, takes away the last strength from old individuals and leads them to death in the cells. In this case, the idea that the mites live for about 2-3 months and the method of shifting the schedule of mites drop for 2-3 months back shows the time of their birth, allowing you to see the real time of birth of this mass of falling mites. And these are the months when the most active reproduction of bees takes place, and when it seemed to us that there were almost no mites in the family (Fig. 11).

Analysis of graphs of mites drop obtained by us for 4 years of continuous observations of six families of bees showed that by studying of free fall of Varroa mites on a sticky board, one can observe the development of the mites population and make predictions about its changes. But, it must be taken into account that the drop of mature mites informs us about what happened in the bee family 2-3 months ago, and makes it possible, although not quite easy, to predict the number of mites at the moment and in the future. This is possible because we know that in average the mites population doubles in a month. The appearance of a drop of pale-colored young mites tells us about a sharp increase in growth of Varroa mites population and an emergency situation in the bee colony. Observing this process can allow beekeepers to urgently take the necessary measures to protect the bees from death.

 

Results 

1) Observations show on the example of all families, that each next burst of the mite's reproduction is at least 2-3 times stronger than the previous one. This difference roughly corresponds to the amount of mature mites fallen free during the present reproductive cycle, divided by the amount of fallen free immature mites of the previous reproductive cycle... The value is approximate, but it is confirmed in all experimental families. You can see it on the graph.

2) Observations show that swarming state of bees should be avoided by all means. It is the massive laying of drone and bee brood before swarming and, most importantly, its thorough heating by the bees, that leads to a catastrophic increase in the mite's population due to a multiple increase in the reproductive territory, comfortable for it.

3) Observations show that if, during the next cycle of enhanced reproduction, free fall of an immature mites significantly exceeds free fall of an old mature dark mites, and has sufficiently large values, then this is a very alarming signal. It can be assumed, that not only a large number of young mites were released, but the founding females did not die ! Thanks to this, it accumulates the mass of live mites, ready to participate in the new reproductive cycle, and exactly this makes the next flash of reproduction so powerful.

During the main honey flow period, when the mites have less bee's brood in the nest for reproduction and in the mites population, remains only young viable individuals, mostly not yet ready to die and fall down on sticky board, free fall of the mites sharply reduces or stops altogether ... With a decrease in the flow of honey at the end of the main honey harvest, as well as with removal of honey by beekeepers at the end of summer, the volume of free space for laying eggs by the queen increases ... The weather conditions at this time, in August-September, are still favorable for the bee's brood rearing  and for the mite's reproduction. At this time, beekeepers are trying to get as many young bees as possible, because exactly these bees will winter and form a family next year. Under these conditions, starts new powerful laying of brood by the mites, which leads to the powerful autumn splash in the growth of Varroa mites population.  This process is accompanied by a strong fall of both - old mites born in spring , and immature young underdeveloped individuals that die in the process of reproduction.

4) Observations show that the state of a bee colony when a quantity of falling mature mites reaches quantity up to 5 mites per day, in principle, is not too bad for a colony of bees of almost any strength. The bees of a strong family can even withstand a situation, when a quantity of falling mature mites reaches 60-70 mites per day, for up to a month.  They are also can withstand a situation when a quantity of falling mature mites reaches from 20 to 40 ticks per day, for 2-3 months. Of course, in the bee's family appear many damaged bees that are unable to fly, and this weakens the family and reduces its honey productivity... We can see such a situation in the graphs of three families of our experimental apiary - 5-1, 5-2, 8-1. At the same time, 8-1 and 5-1 produced about 40 kilograms of marketable honey, and a 5-2 family - 60 kilograms, while being in a stationary apiary. Thus, we can say that the state of a bee colony when a quantity of falling mature mites reaches quantity up to 10 mites per day, in principle, is not terrible in the short term for a strong colony of bees. The danger appears when, in addition to mature dark-colored mites, immature pale-colored mites appear on sticky board. This is a signal of alarm. This is a sign of an incipient reproductive "outbreak" of the mites. So, as you can imagine, the main task of beekeepers is to combat these periodic reproductive outbreaks! Their suppression should be the main task.

 

Discussion

So, thanks to our method of two graphs and based on the results of the control of the mites drop in 6 families for 4 years, we can state that in the life of Varroa mites there are three main peaks of reproduction activity with intervals of greater or lesser decline in reproductive activity between them (Fig. 12 ).


The first peak - is the winter breeding peak. The time of this peak is January, February and March. It is at this time that mountain breeds of bees such as Carnica bees and Caucasian Grey Mountain bees are gradually beginning the process of rearing of this-year's brood. Depending on the strength of the bee colony and the weather conditions, this peak can be large or hardly noticeable ... But as a rule, it is always there. Exactly this peak helps Varroa mites to overwinter and to rear the first young generations, which will give a start to the next, most powerful peak in their reproduction - to the spring pre-honey harvest peak.

The death of the mites of this breeding cycle occurs in March, April, May, and is also accompanied by the death of old females, which wintered together with the bees, and gave life to this generation of the mites. When the winter reproductive peak is insignificant,  free fall of old hibernated female mites is the main part of the mites drop and it tends to stop around mid-May, which can create the illusion that the bee colony is mites-free, if you decision will be based on the size of the mites drop.

The second peak of reproductive activity falls on pre-swarming time - that is, mainly on April, May and June. Undoubtedly, the basis of the danger of this peak is laid precisely in April, when the first mass brood of bees appears and the mites born during the winter peak, and the mites still remaining after wintering, can enter the brood en masse for reproduction. Subsequently, the conditions in a colony of bees preparing for swarming allow the mites to maximize their population in May and June.

The death of the mites of this breeding cycle and their fall on sticky board occurs in the second half of July, August and September. It was at this time that scientists and beekeepers registered the maximal fall of Varroa mites on a sticky board and based on this, talked about the mites population growth ... But this is not entirely true ... It's just that the massive death and fall of the mites of spring breeding cycle coincides with the third reproductive cycle of Varroa mites reproduction - post-honey harvest peak!  Thus, the mites drop tells us about the both - about the death of old mites and about the birth of new ones. We will tell you how this happens a bit later.

The third peak of reproductive activity of Varroa mites falls on the time after honey harvest, when the number of bee brood available for reproduction increases again. In the interval between the second and third peaks, occurs a period of latent reproduction of the mites. The reason for this is the youth of most mites and the absence of a large number of old females for which it is time to die and to fall down on sticky board. At this time, it may also seem that there are almost no mites in the bee colony. This makes the British and American Beekeepers' Association's recommendations for mite control on the basis of counting the number of Varroa mites that fall on a sticky board per day, meaningless. Exactly at this time the mites drop is minimal for natural reasons, and does not say anything about the total number of mites in the bee colony.

The death and fall on sticky board of the mites born during this peak, as well as those born in the fall, occurs more or less evenly and usually continues throughout the winter and spring. As we said, the mites born in late summer and autumn can survive until the first half of May.

 Speaking about the peaks of reproductive activity, one must not forget that between them the mites also reproduce more or less actively and the peaks appear against the fond of some background values. Naturally, such background values are also present in the mites drop.

Understanding the main peaks in the development of Varroa mites population leads us to the understanding that in order to radically reduce the infestation of bee colonies, it is necessary first of all to suppress these peaks in the development of the mites, and especially the winter and spring ones.

So, having come to an understanding of the construction of the life cycle of Varroa mites, it can be argued that the application of a set of rules for keeping bees during the year, which allow reducing colony infestation in a natural way, will provide significant assistance in solving the problem of preserving bees and suppressing the development of Varroa mites in their colonies. What methods can be used for this instead of those, or in addition to those that beekeepers usually use...

Let's consider these methods in chronological order in accordance with the life of bees ...


Wintering: The first step in keeping bees properly in terms of Varroa mites control -  is cold wintering.

There is one very interesting result, as it were, hidden in the diagram obtained by Bee Informed and related to our previous statement about the death of bee colonies in small apiaries from varroatosis, even when beekeepers do not notice it. Pay attention to the diagram Fig.13!  What do the two seasons 2014-15 and 2019-20 have in common?  In common they have the fact that in both cases more bees died in summer than in winter! These years have been extremely warm and with extremely warm winters. With temperatures 5-6 degrees on average above the climatic norm!

What does this mean? It means, that in winter the mites were able to freely breed several new generations in the winter brood of bees, and to increase its population 4-8 times compared to normal years when winters were cold, using February and March and possibly January for breeding!

It is this possibility that should be eliminated. It is this event that will help to lay the foundation for the fight against Varroa mites during beekeeping season. Exactly cold wintering should prevent rearing of winter brood, which is not able to significantly improve the state of bee family,  but is able to become a "farm" for growing Varroa mites. Finally, exactly this event will help to avoid the first spring peak in the growth of the mite's population.

 

Spring development till the main honey flow:  The main methods of influencing the mites population in this period are:  the reduction of the space suitable for the reproduction of the mites and the deterioration of the conditions required for their reproduction. Several techniques can be involved here together or separately ...

1) Creation and maintenance of young families. Creating young families in the apiary to replace old working families by forming artificial swarms, by forming offshoots with mature queen cells, the beekeeper "kills two birds with one stone at once."  Firstly - when creating such families, the brood which at this time is the main repository of the mites, is not used or is used minimally. Secondly -  such colonies are easy to process in any way, including using of organic acids, which is a method, that minimally contaminates frames and honey. Thirdly - the families will have young queens, which is an excellent anti-swarming technique. Such families, as a rule, have a good start in development and begin wintering healthy and clean.

2) Suppression of swarming state of the bees in order to deprive the mites possibility of super-active reproduction in a huge amount of well-heated brood of worker bees and drones. Before the start of the main honey collection, possible methods are:  the presence of young queens, expansion of the nest, removal of maximum possible amount of drone brood. Firstly, as we have already said, colonies with young queens are, in principle, much less prone to swarming. Secondly, the expansion of the nest reduces swarming mood of worker bees and deprives mites of a large, well-heated brood zone and, most importantly, a well-heated drone brood. Thirdly, the use of building frames allows not only to reduce swarming mood of the bees, but also to remove from the hive and destroy almost ninety percent of  drone brood with mites in it, with a minimum expenditure of efforts and without injuring the bee family.

3) Removal of sealed brood. Removal of frames with sealed brood, which can be carried out during the period of spring growth of bee's families in order to prevent swarming and to create offshoots, significantly contributes to the fact, that the disease does not take on a threatening character in the main colonies until autumn, even in the absence of other mites control measures. In addition, holding such an event in June can, under certain conditions, increase honey productivity of bee's families by reducing number of bees engaged in brood rearing. At the same time, the families from which the brood was removed, can be treated with organic acids, and this treatment will be very effective at this stage.


In the process of honey collection, it is possible to influence the mites population using method of of limiting oviposition of the queen. The use of this method will radically reduce the number of mites in the bee colony, by reducing the opportunities for their reproduction.

4) Autumn preparation of bee families for wintering. It is possible that you can again use the method of removing the sealed brood, and then proceed to cooling the nest, in order to stimulate the end of brood rearing season.  The autumn removal of last sealed brood will be useful if in the summer, after honey collection, it was not possible to do this due to the large amount of brood in the bee colony. After the young bees will come out of brood cells in the family in which all sealed brood  was collected,  they can be treated with natural acids against the mites, and after this, the bees can be returned to their families using one of the methods of conjunction of the bees. This will allow both to clear the colonies from the mites, and to preserve their strength for wintering. At the same time, cooling the nest in the fall will help stop brood rearing, which is an incubator for the mites.

 

Conclusion

A study of scientific articles and printed materials, as well as our own researches, have shown that using only chemicals, it is impossible to defeat Varroa mites. When the effectiveness of acaricidal preparations is less than 100%, surviving mites constantly remain, and the overall resistance of Varroa mites to acaricidal preparations is constantly increasing. Today, it is already recommended to use 2-3 acaricidal preparations simultaneously or in turn to treat bees. Nevertheless, the results are deplorable. The rapid development of apiaries producing queens, and most importantly, bee packages, and massive selling them to beekeepers in spring, speaks of the constant death of bees in huge quantities. 

It is not possible to continuously increase the chemical load on the bees, getting worse results from year to year. It is time to draw attention of beekeepers, and first of all, beekeepers who have relatively few bee colonies, to zootechnical methods of combating Varroa mites. All the rules listed here are not a serious burden for such beekeepers. Some of them have been carried out before, but some rules do not seem natural and you need to get used to them and try them out in practice. Then they, like any new business, after a while will also become natural and familiar, and most importantly, they will increase the effectiveness of the fight against Varroa mites.

 

Literature

We used diagrams and a picture from the works :

1.     Population model for the ectoparasitic mite Varroa jacobsoni in honey bee (Apis mellifera) colonies Stephen Martin  National Bee Unit, Central Science Laboratory, Sand Hutton, York, YO4 1LZ, UK

2.     Development of the mite, Varroa jacobsoni oud., in the honeybee, Apis mellifera L., in Michigan, USA, and a comparison of diagnostic methods for detection of the mites Ahmad Al Ghamdi and Roger Hoopingarner

3.     GUÍA TÉCNICA PARA PARA LA LUCHA Y CONTROL DE LA VARROOSIS Y USO RESPONSABLE DE MEDICAMENTOS VETERINARIOS CONTRA LA VARROA   DIRECCIÓN GENERAL DE SANIDAD DE LA PRODUCCIÓN AGRARIA  SUBDIRECCIÓN GENERAL DE SANIDAD E HIGIENE ANIMAL Y TRAZABILIDAD

4.     Population growth of Varroa destructor (Acari: Varroidae) in honey bee colonies is affected by the number of foragers with mites Gloria DeGrandi-Hoffman  Fabiana Ahumada Victor Zazueta Mona Chambers  Geoffrey Hidalgo Emily Watkins deJong

5.     A deadly honey bee parasite, the Varroa mite.  PUBLISHED BY  Bayer AG