Chalk brood

[lindsay s]

There's more than one chalk brood thread on this forum . Here's part of my post from last year which I still think is relevant.

The colony that was bad with chalk brood was of medium strength and on an open mesh floor. More than 50% of the brood was infected. The queen and all the frames were destroyed and the bees were united with a nuc. For as long as I’ve kept bees in Orkney there’s always been chalk brood and some years are worse than others. I’ve tried nearly every method under the sun to try and get rid of it, apart from spraying magic potions on the bees and frames if you know what I mean.
What doesn’t help in Orkney is our cold damp weather , our amm(ish) bees which are supposed to be more susceptible to it and our closed gene pool (no imports of bees to try and keep varroa out). So as you can see the dice is well and truly loaded in the favour of chalk brood up here.
Most of the bee books class chalk brood as a minor brood disease and most of the time things will improve over the summer. But it’s also capable of making a colony unsustainable. How much should we tolerate in a hive, a few cells per frame, a few dozen cells, 25%, 50% or more? I don’t have the answer but would I be wrong to call chalk brood the elephant in the room? I agree with other members of this forum that more research needs to be done on chalk brood and I think no public money should be spent on queen imports.

[mbc]

I am sure there is a large genetic component in it.

I'm sure there is also an age factor involved, with young queens generally tending to lay more robust eggs which turn into more vigorous larvae capable of withstanding more challenges.

[Jon]

Not so sure mbc. I have seen brand new queens mated in Apideas start off with far too much chalk brood.

[mbc]

Well yes Jon, undeniably some are susceptible from the start, but others get worse with age in my experience.

[busybeephilip]

I'm sure chalk brood is most likely associated with hygenic behaviour and has been with AFB - I bet someone has published something in relation to this.

Anyway, as "we" strive to encourage hygenic behaviour in the context of varroa then the only solution is to destroy the offending queen and logically, the drone colony's queen(s) that the offending queen mated with ?

If there is chalkbrood in your new apideas then it is partly due to the drone parental line as well as the maternal line

[busybeephilip]

Jon,

I think you should consider this article http://www.moraybeedinosaurs.co.uk/V...heritable.html in relation to queen raising where emphasis is placed on the inheritance of chalkbrood and the implications that siblings will carry the disease.

If this is the case then the queen mother and drones being used to queen your apideas that show chalky brood may be carrying the genetics for chalkbrood. It might also indicate inbreeding ?

[Jon]

I don't see that much chalk brood, just the odd cell or two, but you always get the odd colony which has far too much.
I don't raise queens from colonies which have chalk brood.

Harbo and Harris have published papers on hygienic behaviour and the relation with AFB and Chalkbrood.

It might also indicate inbreeding ?

From your link

Contrary to the widely held view, no connection could be found between inbreeding and the incidence of chalkbrood. In actual fact reading from fig 4, the opposite of this trend appears to be the case.

[Rosie]

Didn't the link say that the inbreeding effect may have been an artefact because the inbred lines were more highly selected than the others?

[Poly Hive]

FWIW Bernard used to say it was more prevalent in damp cool springs and I have a vague memory that he mentioned Orkney in that regard. His suggested cure was to re-queen as he postulated it was a genetic weakness.

PH

[The Drone Ranger]

some years back I requeened about half of my hives with queens raised from my best hive in Spring that half all had bad chalk brood
I was sure it was genetic and the moral of the story was dont put too many eggs in one basket

On the other hand I have tried just requeening when a hive has had chalkbrood that didn't make any difference
In an earlier post I have mentioned other measure tried

When the requeened bees were shaken on to new foundation and fed the chalkbrood dissapeared
That hive has stayed clear this year

If I was to choose just one measure it would be make a note of any colonies with chalkbrood
The following spring shake all the bees onto new foundation and keep fed till wax is drawn
Without exception burn all the original combs dont try to save the brood or treat the combs

Dont waste money on the mycostop or other "cures" they dont work
There is no effective treatment
Now I only use wood hives so if the theory of warmth is correct then there should be less or no chalkbrood in Poly hives but as I havent read any claims for this it seems unlikely
The genetic disposition may well be true because the infective agent is present in the environment all the time and yet only some hives are affected
I wouldnt count on breeding from a queen that has no chalkbrood as being a safe route though because the queen that produced all the chalkbrood prone daughters had no history of any chalkbrood in her hive

Its a very under explored area you will see white fluffy mummies or smaller black mummies which as I understand it are the infectious stage
If your bees are prone to chalk they may do better on a solid floor with the hive tipped toward the front because it makes the ejection of mummies much easier
The fungus apparently needs two strains to be present for reproduction (that may be faulty memory please correct)
When it spontaneously just dissapears its fairly likely it hasn't really got fully to the infectious spore forming stage
Once combs have been infected by those spores though they are effectively useless (I feel)

Theres an article here but I'm not a member of Ibra so hopefully someone who is will give us the low down on their findings
http://www.ibra.org.uk/articles/Effe...eybee-colonies