Aspergillosis of bees (stone brood) is a fungal disease of the larvae of bees of all ages and also of adult bees. Although the causative agent of this infection is very common in nature, the disease of bees is rarely found in the beekeeping industry. Its appearance is usually associated with a period of active honey flow or damp spring weather. But the consequences of an infection can be dire. To prevent this from happening, you need to take measures to combat the fungus as soon as possible.
What is the danger of the disease
Bee aspergillosis can spread very quickly. Having appeared in one family, in a few days the infection can affect all the hives in the apiary. The disease is equally dangerous for bees, birds, animals and humans. The disease affects the mucous membranes of the organs of vision and respiration, mainly the bronchi and lungs, as well as the skin.
Once in the body of the larva, aspergillosis spores act on it in two ways:
- mycelium grows through the body of the larva, weakening and drying it out;
- a toxin is produced, which has a destructive effect on the nerve and muscle tissue of the brood.
After a few days, the larvae die. Aspergillus enter the organism of brood and bees along with food or through external damage in the body.
Causative agents of aspergillosis in bees
The disease is caused by the widespread moldy, yellow fungus Aspergillus (Aspergillus flavus), which is widespread in nature, less often by its other varieties: Aspergillus niger and Aspergillus fumigatus. Fungus develops on plants and organic dead remains. It is a mycelium of long fibers of hyphae, which rise above the nutrient medium by 0.4-0.7 mm and have fruiting bodies in the form of a transparent thickening. Colonies of Aspergillus flavus are greenish-yellow and niger are dark brown.
Spores of the Aspergillus fungus live almost everywhere: in the ground, on its surface, on living and dead plants. Being on the anthers and in the nectaries of flowers, the spores, together with the pollen, are picked up by the collecting bees and delivered to the hives. Further, worker bees on their legs and hairs easily transfer them, transfer them to other adults and larvae during harvesting and feeding. The fungus multiplies on combs, bee bread, larvae, pupae, adult bees.
The following conditions contribute to the manifestation of aspergillosis:
- air temperature from +250From to +450FROM;
- humidity above 90%;
- rainy weather;
- large herbage;
- the location of houses on damp ground;
- a weakened bee colony;
- poor insulation of hives.
The most common bee aspergillosis in spring and summer, since it is during this period that all the circumstances provoking the disease appear.
Signs of infection
You can find out about the appearance of stone brood in bees by the appearance and condition of the larvae. The incubation period lasts 3-4 days. And on the 5-6th day, the brood dies. Having entered the body of the larva through the head or between the segments, the fungus grows, changing it outwardly. The larva becomes light cream in color, shriveled and without segments. Due to the fact that the moisture in the larva is actively absorbed by the mycelium of the fungus, the pupa dries up and feels solid (stone brood).
The fungus forms spores on the surface of the dead larva, and depending on the type of fungus, the larva becomes light green or dark brown. Since the mycelium of the fungus tightly fills the cells, the larvae cannot be removed from there. When the disease is advanced, the fungus covers the entire brood, the lids of the cells seem to have failed.
Adult bees are most often affected by aspergillosis in the spring. They first become agitated and actively move, their abdominal breathing increases. After a short time, the diseased bees weaken, cannot stay on the walls of the combs, fall and die after a few hours. Externally, insects with aspergillosis almost do not differ from healthy ones. Only their flight becomes heavier and weaker.
The mycelium of the fungus, growing in the intestines, permeates the entire body of an adult bee. It also grows behind the head in the form of a kind of collar. When squeezing the abdomen and chest of a dead insect, it is found that they have become hard. Dead bees appear hairier due to mold germination.
The diagnosis of bee aspergillosis is made on the basis of characteristic external signs of dead brood and adults, as well as after microscopic and mycological studies. Research results are ready in 5 days.
At least 50 diseased bees or corpses from fresh dead and a piece (10x15 cm) of honeycomb with sick and dead brood are sent to the veterinary laboratory in glass jars with tight lids. Delivery of the material must be carried out within 24 hours from the moment of its collection.
In the laboratory, scrapings are made from the corpses of larvae and bees to identify the sporulation of the aspergillosis fungus. When conducting laboratory research, the disease of ascopherosis is excluded.
Attention! If the bees and brood have characteristic changes and the causative agent of the disease is found in the crops, then the laboratory diagnosis is considered established.
How and how to treat stone brood in bees
When the veterinary laboratory confirms the disease "aspergillosis", the apiary is declared dysfunctional and quarantined. In case of minor damage, appropriate treatment of bees and brood is carried out. They also disinfect the entire bee farm.
In isolated cases of the death of the larvae, the combs, together with the bees, are moved to a dry, warm and disinfected hive. Then, bee aspergillosis is treated with special drugs, as in ascopherosis, approved by the Department of Veterinary Medicine:
Of all the drugs listed, only Unisan can be used alone. In other cases, it is recommended to entrust the treatment to specialists.
To use "Unisan", the agent in a volume of 1.5 ml is stirred in 750 ml of sugar syrup prepared by mixing sugar and water in a ratio of 1: 4. The "Unisan" solution is sprayed with:
- the walls of the hive inside;
- populated and empty honeycombs;
- frames on both sides;
- bee colonies with brood;
- equipment and work clothes of the beekeeper.
The procedure is repeated 3-4 times every 7-10 days. Processing must be completed 20 days before the start of honey collection. "Unisan" is a safe product for humans. After this treatment, honey is good for consumption.
Before the start of the treatment for aspergillosis of bees, diseased colonies intensify. If the uterus is sick, then it is changed to a healthy one, the nest is shortened and insulated, and good ventilation is organized. The bees are provided with enough honey. With a lack of honey, they feed them 67% sugar syrup.
Warning! It is prohibited to use bee products from bee colonies with aspergillosis.
When working with infected bees, beekeepers, in order to avoid getting fungal spores on the mucous membranes, should take all precautions and wear a dressing gown, a damp 4-layer gauze bandage on the nose and mouth, and goggles on the eyes. After finishing work, you need to wash your face and hands with soap, and boil your work clothes.
Processing of hives and inventory
If bee colonies are severely affected by aspergillosis, then they are destroyed by lighting with sulfur dioxide or formalin, and insulating material with laps and honeycomb frames is burned. Given the rapid spread of bee aspergillosis, as well as the danger of the disease for the entire apiary, the following processing of the hives and equipment is carried out:
- physically cleanse of debris, corpses of bees and larvae, propolis, wax, mold and mildew;
- treated with 5% formaldehyde solution or blowtorch flame;
- the soil under the hives is dug up with the addition of a 4% formaldehyde solution or a clarified solution of bleach;
- dressing gowns, face nets, towels are disinfected by boiling for half an hour or soaked in 2% hydrogen peroxide solution for 3 hours, then washed and dried.
To process the hive with a 5% formalin solution, add 50 ml of the substance, 25 g of potassium permanganate and 20 ml of water to a small container. Place the container in the hive for 2 hours. Then treat the hive with 5% ammonia to remove formalin vapors.
Instead of a blowtorch, you can use a construction hot air gun. Using a hot air gun eliminates the risk of fire, and the air temperature can reach +800FROM.
After carrying out disinfection measures, hives and all equipment are washed well and dried thoroughly. If the combs can still be used, then they are treated in the same way as the entire inventory. In case of severe fungal infection, the honeycomb is melted onto wax for technical purposes.
The quarantine is removed one month after the complete destruction of bee aspergillosis in the apiary.
A set of preventive measures
In order to prevent brood and bee aspergillosis disease, you need to adhere to certain rules and take a number of preventive measures:
- before installing the hives, you need to process the land plot with lime for disinfection;
- keep only strong families in the apiary;
- place the apiary in dry, well-lit by the sun, places;
- avoid dense grass;
- reduce nests for the winter and insulate them well;
- during the absence of honey collection, provide bees with complete food;
- keep the houses clean, ventilated and dry;
- do not carry out any activities with hives in cold and damp weather;
- do not use antibiotics to strengthen bee colonies, which weaken the immunity of insects.
High humidity in hives at any time of the year is the worst enemy for bees and can lead to fatal disease. Therefore, the apiary should have dry and warm houses all year round.
Bee aspergillosis is a dangerous disease for any beekeeping industry. It can affect not only brood, but also adult bees. Every beekeeper needs to know the signs of this disease, methods of its treatment and precautions in order to deal with it in a timely and effective manner.