Ascospherosis of bees: how and what to treat

Ascospherosis is a disease that affects the larvae of bees. It is caused by the mold Ascosphera apis. The popular name for ascospherosis is "calcareous brood". The name is aptly given. The larvae affected by the fungus after death are very similar to small chalk balls.

Why is ascospherosis dangerous?

A fungus that has grown to a visible state looks like white mold. That is what he is. Ascospherosis affects mainly drone larvae at the age of 3-4 days. Like any mold, the fungus grows on weakened organisms. Bees infected with varroa are more likely to be affected by ascospherosis.

This type of fungus is bisexual. It has sex differences in vegetative filaments (mycelium). When two threads merge, a spore is formed, which has a very sticky surface. Due to this property, spores can spread not only within the same hive.

The most frequent cases of ascospherosis are summer. Mold grows in damp places and high humidity. Favorable conditions for the development of ascospherosis arise:

  • rainy summer with high humidity;
  • when keeping an apiary in a humid area;
  • after prolonged cold snaps;
  • with excessive use of oxalic and lactic acid.

Organic acids are often used by beekeepers to combat another bee problem - varroatosis.

Attention! Drone brood located near the walls of the hive is most susceptible to ascospherosis.

In these places, the conditions for the reproduction of the ascosphere apis are most favorable, since the walls of the hive can become damp due to insufficient or improper insulation. Air circulation is also worse than in the center, where bees work hard with their wings.

Bee disease symptoms

The appearance of ascospherosis in the hive can be seen by the dead larvae lying in front of the hive, on the landing site or at the bottom under the combs. When checking the hive, you can see a white bloom on the bee larvae. If the cell is not sealed, the head end of the larva is moldy. If the cells are already sealed, the fungus will grow through the lid and infect the larva inside. In this case, the honeycomb looks covered with a white coating. In the opened cells, you can find hard lumps attached to the walls of the honeycomb or lying freely at the bottom of the cells. These are the larvae that died from ascospherosis. These "lumps" occupy about ⅔ of the honeycomb volume. They can be easily removed from the cell.

Infection methods

Fungal spores infect larvae in two ways: from the inside and through the walls of the honeycomb. When it enters the intestine, the spore grows from the inside and then spreads through the walls of the honeycomb to other cells. Mold grows through the caps and braids the honeycomb completely.

When spores get on the skin of the larva from the outside, the mycelium grows inward. In this case, ascospherosis is more difficult to detect, but there is a chance that it will not take on catastrophic proportions.

Ways of transmission of ascospherosis:

  • the introduction of spores together with pollen into the hive by bees that have returned home;
  • rearrangement of frames with bee bread, honey or brood from an infected hive to a healthy one;
  • when a bee feeds an infected feed to a healthy larva;
  • spread by bees cleaning infected cells;
  • when using equipment common to the entire apiary;
  • with insufficient disinfection of the hives.

Initially, bees bring the fungus from greenhouses, where it is always warm, humid and poor air circulation. Mold thrives in greenhouses, and once it gets on a bee, it begins to grow in a living organism. Due to the fact that the mycelium grows into the body of a bee or larva, ascospherosis is very difficult to treat.

Stages of the disease

Ascospherosis has 3 stages:

  • easy;
  • medium;
  • heavy.

The easy stage is also called hidden, since the number of dead larvae is no more than 5 pieces. This amount is easily overlooked or attributed to other reasons. But mold tends to grow and move to the next step. The average degree is characterized by losses of larvae from 5 to 10.

Losses in severe form are 100-150 larvae. It is believed that mild to moderate forms can be left untreated, since the losses are low. But ascospherosis is a bee disease caused by a fast-growing living organism. It is easier to eliminate mold as soon as its focus has been noticed than to wait until the fungus grows and matures into spores.

Important! By the number of dead larvae, it is determined at what stage the ascospherosis is.

How to treat lime brood in bees

Ascosphere apis is sensitive to fungicides just like any other mold. The main thing is not to overdo the dosage and not poison the bees at the same time. Garden fungicides, however, should not be used. Their concentration for plants should be higher, and it will be too expensive to select a dosage for bees using an experimental method. For the treatment of ascospherosis in bees, individual fungicides have been developed:

  • levorin;
  • ascozol;
  • ascovitis;
  • mycosan;
  • larvasan;
  • clotrimazole.

Also, nystatin is recommended as an antifungal drug, but the opinions of beekeepers about it are sharply opposite. In addition to industrial antifungal drugs, beekeepers are trying to treat ascospherosis with folk remedies:

  • garlic;
  • horsetail;
  • onions;
  • celandine;
  • yarrow;
  • iodine.

Of the folk remedies, iodine is the most effective. In fact, all other methods are based on the presence of free iodine ions in garlic and onions. The concentration of these ions is low and extracts are required.

Antifungal drugs only stop the growth of the ascosphere. There is only one guaranteed way to get rid of ascospherosis: complete burning out of infected bees. If the bee colony is weak, it is best to do so.

How to treat ascospherosis of bees

Since any mold is difficult to destroy, in the treatment of ascospherosis it is necessary to carry out a whole range of measures aimed at stopping the development of the fungus:

  • carry out the processing of all hives in the apiary;
  • bees are moved to a new disinfected hive;
  • bees are treated with fungicidal preparations.

To destroy the fungus inside the bees, it is convenient to use a fungicide diluted in sugar syrup. Such treatment of bees from ascospherosis is best done in the fall after honey pumping. After harvesting honey, the bee colony is still fed with sugar to restore food reserves for wintering. The sale of such honey is prohibited, and it is undesirable to apply such treatment in the spring. But the bees will supply "medicine" and the larvae in the cells.

Driving bees

Treatment of ascospherosis begins with placing a colony of bees in a new disinfected hive. Honeycombs taken from a healthy family and new dryness are placed in it. The old infected uterus is replaced with a young healthy one.

Severely infected brood is removed and the wax is reheated. If the combs are not severely infested, they can be placed in the hive by isolating the queen from the brood. But if possible, it is better to get rid of diseased larvae, even if there are several of them. Mold grows quickly. Podmore burn, and do not insist on vodka or alcohol as a panacea for all diseases.

Attention! Some time without brood helps to get rid of the family from ascospherosis.

Since the bees themselves can also be infected with mycelium or ascosphere spores, they are treated with medications or folk remedies.

Treatment of bees from ascospherosis with a drug method

The method of using drugs for ascospherosis of bees depends on the form of the drug and the time of year. In spring, early summer and autumn, fungicides can be fed with sugar syrup. In summer it is better to use spraying. Doses and methods of administration can usually be found in the instructions for the drug.

Syrup for feeding is prepared in a ratio of 1 part water to 1 part sugar. For spraying, take a less concentrated solution: 1 part sugar to 4 parts water.


To feed 1 ml of ascozol, it is diluted in 1 liter of sugar syrup at a temperature of 35-40 ° C. They feed 250-300 ml per day per family for 1-2 weeks. You need to feed it every other day.

In summer, bees, walls and frames in the hive are sprayed with the drug. For spraying, 1 ml is diluted in 0.5 l of a less concentrated solution. Spraying is carried out with a fine spray gun. Consumption of the composition is 10-12 ml per one honeycomb frame. Spraying is repeated every 2-3 days until the family recovers. This usually requires 3 to 5 treatments.


This fungicide acts on the redox enzymes of the ascosphere. It is usually used as a top dressing. For 1 liter of syrup take 500 thousand units. Levorin. Give twice with a break of 5 days.


Preferably used for treating hives. The walls and frames are sprayed with aerosol. Consumption of half a bottle per hive. When feeding, make an 8-10% solution.


One of the most effective fungicides. Used for spraying hives. In autumn, add to sugar syrup for feeding.


Iodine is difficult to attribute to both folk methods of fighting ascospherosis and industrial ones. He is "in the middle". Levorin is an iodine-based industrial drug. But iodine fungicide can be made by hand.

Treatment of ascospherosis in bees with monochlorine iodine is very effective, according to beekeepers. In this case, he is not even fed or sprayed with the frames and the wall. 5-10% monochloride iodine is poured into polyethylene lids, covered with cardboard and placed on the bottom of the hive. By evaporating, the drug stops the development of the fungus.

A solution of iodine in sugar syrup for processing the hive is made independently. Iodine tincture is added to the syrup until a light brown liquid is obtained. Spraying with this composition is carried out once every 1-2 days. The solution can also be used to feed the bees.

Attention! Before each treatment, a new solution must be prepared, since iodine decomposes quickly.

Treatment of ascospherosis in bees by alternative methods

Really folk methods include attempts to cure ascospherosis with herbs. Even for prevention, this is poorly suited. Bunches of yarrow, horsetail or celandine are wrapped in gauze and placed on frames. Harvest when the grass is completely dry.

The garlic is kneaded into gruel, wrapped in plastic and laid out on frames. Of all the folk remedies for fighting mold on bees, garlic is the most effective.

Dried herbs are also used. They are crushed into dust and sprinkled on bee streets. A handful of powder is consumed per hive. A decoction is made from field horsetail: they are folded, without ramming, into a saucepan, poured with water and boiled for 10 minutes. Insist 2 hours, filter and make a syrup for feeding. Give the syrup to the bees for 5 days.

Sometimes a strong solution of potassium permanganate is used. But this product can only be used to disinfect the wooden parts of the hive.

Decontamination of hives and equipment

There are many ways to disinfect hives, but treatment with any of the methods should be carried out as soon as possible, since the mycelium of the fungus will grow into the wood. If this happens, there will be only one way to cure ascospherosis: to burn the hive.

The hive is burned with a blowtorch or "drowned" for 6 hours in an alkaline solution. Small items of inventory are disinfected twice. If possible, they can also be soaked in alkali. The honey extractor is coated with a strong solution of lye or laundry soap and left for 6 hours. Then it is thoroughly washed with water. All fabric items are boiled.

The honeycomb is removed from the infected hives and the wax is reheated. If there are more than 50 infected larvae, the wax is suitable only for technical purposes. Merva is destroyed from him.

It is undesirable, but you can use combs from a family slightly infected with ascospherosis. In this case, the honeycomb is thoroughly disinfected. At the rate of 100 liters of disinfectant take 63.7 liters of water, 33.3 liters of perhydrol, 3 liters of acetic acid. In this amount, 35-50 frames with honeycombs can be processed. The honeycombs are kept in the solution for 4 hours, then dried thoroughly.

A set of preventive measures

The main prevention of any mold is its prevention. The most favorable conditions for the development of ascospherosis are dampness, lack of ventilation and a relatively low temperature. In this case, no immunity will save. For prophylaxis, it is necessary to provide bee colonies with acceptable conditions. If the hives remain outside for the winter, make external insulation and good ventilation.

Important! Condensation always forms between the insulation and the main wall and mold begins to grow.

It is for this reason that the hive should be insulated from the outside, not from the inside.

It will not be possible to completely avoid dampness, especially if the winter is warm and slushy or there have been thaws. Therefore, in the spring, the first thing the bees are transplanted into a clean, free from ascosphere, hive, and all frames are checked and affected by ascospherosis are thrown away.

Another way to avoid ascospherosis is to feed the bees with pure honey, not sugar syrup. The syrup weakens the bees and is only allowed for medicinal purposes. The collected pollen is also left to the bees. A strong colony of bees is less susceptible to ascospherosis than a family weakened by hunger.

Do not use equipment from someone else's apiary. She can be infected with ascospherosis. Periodically, it is necessary to take samples from the hive and pass tests for the presence of pathogenic microorganisms. Dead water and other debris from the bottom of the hive will do.

Important! The hives need to be cleaned systematically.


Ascospherosis is able to leave the beekeeper without basic means of production. But with a careful attitude towards bee colonies, the growth of the fungus can be noticed even at the initial stage and measures can be taken in time.

Watch the video: Treating a hive with powder sugar for Varroa Mite Destructor (June 2021).