A Discussion on Foulbrood

[Calum]

This Conversation originated in the Beekeeping Myths Thread but a few of us felt that it was far too useful and interesting to be buried within what is a fairly lighthearted topic so I've broken the relevant posts out into this thread.

Nellie.

Good tip from our FB. Make casts from colonies that want to swarm. But break out all their queen cells after 5 days and add a frame form your best colony, otherwise you will breed colonies that want to swarm more over time.

Also don't give stores frames/feed a swarm for 2-3 days after capture so they use their own recourses. Otherwise if they carried AF in their stomach full of honey they will store it with all the problems that entails. Starve them a bit and they'll eat it up resolving the problem.

[Jon]

Are you posting the foul brood thing as a tip or a myth!
I wonder how many colonies with foul brood would be capable of growing enough to produce a swarm which carried spores.

[Calum]

a tip. If the hive you put them in has food, they'll empty their bellies and the spores are in the new hive. which they will then raise their first young with.

[Jon]

I was more thinking along the lines of, can colonies with foulbrood ever grow strongly enough to be capable of swarming. Foulbrood is a severe drain on resources and must restrict colony growth. They say most foulbrood cases are caused by beekeepers moving equipment about, especially old comb, or else bees robbing out a colony which has succumbed to foulbrood. Ruary might know something about the possibility of swarms carrying foulbrood spores.

[Neils]

Must admit that I wouldn't like to commit something in writing around it one way or another. I certainly get the reasoning behind it but if you've got a swarm full of honey, diseased or not, would they take the feed to make comb to store the diseased honey? If you fed a heavy syrup would that change things?

[gavin]

Ruary might know something about the possibility of swarms carrying foulbrood spores.

Pretty sure that it happens.

Anyway, back to the myths: EFB is a stress disease. (As in, promoted strongly by stress rather than causing it).

[Jon]

I think a lot of bee disease is stress related and for that reason alone it is good to minimize disturbance**, disruption, heavy handling, opening on cold days etc.

I have read, may be another myth, that foulbrood spores are usually present in a colony, same as nosema spores, but it takes stress to raise the spore count to a critical level and induce the symptoms of the disease.

**Not yet advocating let alone beekeeping

[gavin]

Yeah, I have read that too and had it quoted at me from people who should know better. Simply don't believe it. EFB is missing from large areas and is still actively colonising parts of the UK. Once it it there it may bubble up again from latent infection (eg contaminated comb) but I don't believe that it is near-ubiquitious and awaiting stress to trigger it. Tooth fairy stuff.

[mbc]

EFB is missing from large areas and is still actively colonising parts of the UK. Once it it there it may bubble up again from latent infection (eg contaminated comb) but I don't believe that it is near-ubiquitious and awaiting stress to trigger it. Tooth fairy stuff.

Hardly tooth fairy stuff, it just needs a little qualification to make it entirely accurate.
If the causative agent, melissococcus plutonius, is present at a sub clinical level then a stress event (typically a dearth of food when there is brood to nurture) can trigger a clinical outbreak of what we know as EFB, of course if the causative agent isnt present it wont magically appear out of thin air.
Colonies with AFB frequently get up to swarming strength and swarm if they go undetected, the 'dont feed a swarm for a couple of days' tip is a percentages thing, we may as well make it less likely that anything is passed from one generation to the next ( vertical transmission).
Finally, the forest fire/smoke thing will never be known unless bee psychiatry jumps to fantastic levels where we can really plumb the depths of a bee's mind, my money's on it being partly true and the confusion caused by the foreign smell of danger helps distract the bees from defensive behaviour.

[Calum]

Colonies with AFB frequently get up to swarming strength and swarm if they go undetected, the 'dont feed a swarm for a couple of days' tip is a percentages thing, we may as well make it less likely that anything is passed from one generation to the next ( vertical transmission).

If you gather a swarm that is of unknown origin you have two choices to try and protect yourself from them bringing (possibly large levels of) FB spores with them.
1. Burn a sulphur strip in the swarm box after collection (with the bees still in it)
2. Starve them a bit

choice one is 100% sure to protect you
choice two is a percentages thing