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Baggy brood is an infectious disease that kills bee larvae and young pupae. On the territory of Russia, this infection is widespread and causes economic damage, causing the death of bee colonies. In order to stop bee brood diseases in time, you need to see their signs as early as possible (for example, in the photo), learn methods of treatment and prevention.
What is this disease Sacred brood
The name of the disease "Sacred brood" comes from the appearance of diseased larvae. When infected, they become like sacs filled with fluid. The causative agent of this disease is a neurotropic virus.
It affects the larvae of the printed brood of honey bees, drones, and queens of all breeds. The most susceptible to the disease are young larvae, which are from 1 to 3 days old. The incubation period of the virus is 5-6 days. The prepupae die at the age of 8-9 days before being sealed.
Bee brood disease occurs after a virus enters the body, which is very resistant to all kinds of physical and chemical effects:
- drying;
- chloroform;
- 3% caustic alkali solution;
- 1% solution of rivanol and potassium permanganate.
The virus retains its viability being:
- on honeycombs - up to 3 months;
- in honey at room temperature - up to 1 month;
- when boiling - up to 10 minutes;
- in direct sunlight - up to 4-7 hours.
Due to the death of the larvae, the bee colony is weakened, the productivity of the honey plant decreases, in severe cases the colonies die. Adult bees carry the disease in a latent form and are carriers of the virus in the winter season.
Saccular brood appears in central Russia, at the beginning of June. In the southern regions a little earlier - in May. During the abundant summer honey plant, the disease subsides or disappears altogether. It may appear that the bees have dealt with the virus on their own. But in early August or next spring, an untreated disease manifests itself with renewed vigor.
Possible causes of infection
The carriers of the infection are considered to be adult bees, in whose body the virus persists throughout the winter. Different insects can transmit the virus:
- inside the family, the disease is spread by worker bees, who, cleaning the hives and removing the corpses of infected larvae from them, become infected themselves, and when feeding healthy larvae with food, they transmit the disease;
- varroa mites can also bring disease - it was from them that the sac brood virus was isolated;
- thief bees and wandering bees can become a source of infection;
- untreated work equipment, combs, drinkers, feeders may also contain infection.
Infected worker bees are the most common carriers of the virus between families in the apiary. The spread of infection occurs when raids are made, or it can occur when rearranging honeycombs from sick bees to healthy ones.
Signs of bee brood disease
The incubation period for the development of the infection lasts 5-6 days, after which you can easily notice the signs of saccular brood, as in the photo, after examining the combs:
- the lids are open or perforated;
- honeycombs have a variegated appearance due to the alternation of sealed cells with empty ones;
- the larvae look flabby and watery in the form of sacs;
- corpses of larvae are located along the cell and they lie on the dorsal side;
- if the larvae are already dry, they look like a brown crust with the front part bent up.
Externally, the combs with the affected brood resemble a rotten disease. The difference is that with saccular brood there is no rotten smell and a viscous mass when removing corpses. Also, with saccular brood, the infection spreads more slowly than with foulbrood. In the first summer, from 10 to 20% of families can get sick. If the disease is not treated, then in the second summer up to 50% of the bees in the apiary can be affected.
In a strong colony, bees discard dead brood. A sign of a weakened family - the untouched corpses of the larvae remain to dry out in the cells. The degree of damage by saccular brood is determined by the number of dead larvae in the combs.
How to diagnose baggy brood in bees
Bees can suffer from several diseases at once, including saccular brood, which have common features with American and European foulbrood. In this case, clear signs of this disease are not easy to detect. To dispel all doubts, a 10x15 cm sample of combs is sent to the laboratory for analysis.
Currently, there are many methods for laboratory diagnosis of viral diseases of bees:
- linked immunosorbent assay;
- polymerase chain reaction (PCR);
- chemiluminescence method and others.
They all have several disadvantages for detecting strains of the same virus. The most accurate is the polymerase chain reaction.
Analysis results are ready in 10 days. If the disease is confirmed, then quarantine is imposed on the apiary. If up to 30% of the bees get sick, the beekeeper separates the sick families from the healthy ones and takes them out to a distance of about 5 km, thus organizing an isolator.
When more than 30% of those infected with sac brood are found, an isolator is organized in the apiary, and all families receive the same feeding.
Baggy bee brood: treatment
If an infection is detected, the apiary is quarantined. Treatment of saccular brood is carried out only for weakly and moderately damaged colonies. Families with severe damage are destroyed. Before starting the treatment itself, several measures are taken to improve the health of the sick family:
- Brood frames are added to infected hives at the exit from healthy colonies.
- They replace diseased queens with healthy ones.
- They insulate the hives well and provide the bees with food.
Also, for strengthening, two or more sick families are brought together. Treatment should be carried out in disinfected hives, from which frames with a large amount of diseased brood are removed.
There is no cure for infection as such. The agents used to treat sick bees with saccular brood only weaken the symptoms of the disease in bees. In the first half of summer, individuals infected with saccular brood are fed with sugar syrup with the addition of Levomycetin or Biomycin (50 ml per 1 liter of syrup).
In the opinion of beekeepers, the treatment of saccular brood can be carried out using the Endoglukin aerosol. Spraying is carried out 3-5 times every 5-7 days. In this case, the air temperature should be within + 15 ... +220FROM.
Temporary (for 1 week) cessation of oviposition is considered an effective way to control the spread of saccular brood. To do this, the queen of the hive is removed, and an infertile uterus is planted in her place.
Disinfection of hives and equipment
Sanitary processing for saccular brood of wooden objects, including hives, is carried out as follows:
- Sprayed with 4% hydrogen peroxide solution (0.5 l per m22).
- After 3 hours, wash with water.
- Dry for at least 5 hours.
After that, new bee colonies can be populated into the hives, and the wooden equipment can be used for its intended purpose.
The rest of the accessories used when working in the apiary undergo the same disinfection as in the case of foulbrood disease:
- honeycombs from sick hives are subjected to overheating at t 700With or disinfected with vapors of 1% formalin solution (100 ml per 1 m3), then ventilated for 2 days and only then used;
- honeycombs can be treated with a 3% solution of hydrogen peroxide, irrigated until the cells are completely filled, shake, rinse with water and dry;
- towels, dressing gowns, laps from the hive are disinfected by boiling for half an hour in a 3% solution of soda ash;
- facial nets are boiled for 2 hours in 1% hydrogen peroxide solution or 0.5 hours using Vetsan-1;
- metal implements are treated with 10% hydrogen peroxide and 3% acetic or formic acid 3 times every hour.
One of the simple and effective methods of disinfection is considered to be blowtorch treatment.
The land plot on which hives with infested saccular brood families stood is treated with bleach at the rate of 1 kg of lime per 1 m2 by digging to a depth of 5 cm. Then, abundant watering of the area is applied.
Prevention methods
It was noted that the greatest distribution of saccular brood occurs in cool, damp weather, in weak bee colonies, in poorly insulated hives with insufficient nutrition. Therefore, in order to prevent the appearance and spread of bee brood disease, certain conditions must be created in the apiary:
- keeping only strong families;
- sufficient food supply;
- complete protein and vitamin supplementation;
- timely renewal and insulation of the hive, good maintenance;
- mandatory check of the hive in the spring, especially in damp cool weather;
- location of bee houses in dry, well-sunlit places;
- regular cleaning and disinfection of beekeeping equipment every spring after hibernation of bees.
It is necessary to inspect the hives at least once every 2 weeks. At the first sign of saccular brood, every precaution should be taken to keep other bees healthy.
Conclusion
The baggy brood cannot be completely cured, since the exact method of treatment has not yet been developed. Three-fold application of the recommended drugs with an interval of 7 days only removes the clinical signs of the disease. The virus remains in the family as long as there is the varroa mite, the main carrier of the virus. Nevertheless, creating favorable conditions for the formation of strong bee colonies reduces the risk of spreading saccular brood.
