Sacbrood

[Breeder of queens Koss]

Hi all!
This disease was mentioned in one topic, I did not find any other sources on this forum.
How common is this disease and how do you treat it?

 

[Alastair]

Here is quite a good fact sheet on it. It is reasonably common, in my view more so when hives are under some kind of stress. There is no cure for it but it is very unusual for it to infect enough larvae to have any noticeable effect on the hive as a whole.

Do you have it in your country?

NZ Government

www.mpi.govt.nz

 

[tristan]

no treatment. its not really something thats a problem. usually shows up more in hives of poor health, especially hives with varroa issues.

 

[John B]

Definitely a stress thing and quite possibly related to chilling coupled with rapid brood expansion in the spring. Definitely worse some years than others and generally clears up by itself. There may be some genetic predisposition to this problem and I have seen cases that only cleared up after requeening.
I have seen hives quite debilitated with sack brood but it is quite rare and you have to wonder whether the sack brood caused the problem or whether another problem caused the sack brood.
If you have never seen this problem in your hives then you're probably not looking hard enough. It is a lot more common than AFB and has very similar symptoms. You can of course have both in the same hive , it's rare but I have seen it.
If I only find the odd cell then I just ignore it. As others have said, it will go away by itself.

 

[Breeder of queens Koss]

Alastair, Tristan, John B thanks for the information!
Yes, sacbrood is the same in my country, and this season it appeared in my apiary.
I looked for information on treatment, but other than recommendations for disinfection and compression of the nest, I didn’t find much.
Since this disease is of viral origin, bees with good immunity do not have this disease. I think the virus is present throughout the apiary, due to contact with a common water source, and wandering drones or bees, but not all colonies have it.
My mistake is that I greatly expanded the nest in the spring, which caused stress in the bees.
For myself, I decided to do an experiment. To break the vicious circle - an infected bee feeds a larva, the larva dies, the bee removes this larva and becomes infected. I caught the queen bee and put her in a cage. I don’t know for how long, maybe I’ll try different things, but definitely until all the open brood becomes sealed. And squeezed the nest. And I will give 0.3-0.5 liters of sugar syrup.
If you're interested, I can share the results when I finish the experiment

 

[Alastair]

Hope it will work.
But sac brood normally clears up by itself.

 

[jakefinefairlad]

Sacbrood imo is more common than wed think, especially during stressful seasons. You're right about the virus being present across the apiary, spread by drones, shared water sources, or robbing. From my experience, the most important thing is keeping the bees strong and reducing stress just like you said. Closing down the hive in early spring can sometimes put too much strain on them. One thing I've done is requeening. A new, younger queen often helps strengthen the hive and break the infection cycle. Also, feeding a protein supplement can boost their immunity.
About your experiment, sounds interesting! Caging the queen might help slow the spread, but I'd watch the colony closely. Sometimes too much manipulation can cause even more stress. I realize some time has passed since your question, hows it going?

 

[Breeder of queens Koss]

Hi! I'm fine and so are the bees)) The bees are ready for winter, and I can calmly take a break from them.
Some queen bees were replaced after that. But basically, as they said, sacbrood goes away on its own. Replacing a sick queen with a new one is also a great idea, and this method also helps well.
This year, 75% of the apiary went into winter without treatment. The last time they were treated was in November 2023. To be honest, I'm a little worried. In 4 months it will be clear how correct my calculations were...