when they suggest that there is a genetic component to a colonies susceptibility to chalk brood, is it the susecptibility to the fungus itself that is genetic or the hygienic temperament of the colony?Originally Posted by Jon
when they suggest that there is a genetic component to a colonies susceptibility to chalk brood, is it the susecptibility to the fungus itself that is genetic or the hygienic temperament of the colony?
I was told recently by a very experienced breeder that chalk susceptibility is linked to recessive genes and hence to inbreeding. Outcrossing but within race is reckoned to fix it. If you are trying to line breed to fix a strain then you have to accept chalk along with other inbreeding problems such as depression so that you can later outcross with another inbred line to produce powerful production colonies.
Rosie
Hi Adam
I think it’s time to dig this thread out again.
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.
Hi Lindsay
I've been having a few thoughts on chalk brood and why it not only shows up in it's own right but in conjunction with other brood disease and varroa attack
I figure it's always present in the hive and gets a grip when there is stress
That might work for the bees sometimes by mummifying larva who are already infected by something else
Also any varroa who climbed in with the larva are dead ducks
When there is poor weather or lack of food it reduces the colony strength
Anyway that's all speculation
What I think might help is a top entrance to the broodbox that stops the incoming bees walking through ejected mummies on the floor
Because the bees can't then easily pick them up and get rid of them you would need a floor that allowed the mummies to fall through
Under that floor you could have a tray with something in it to stop the mummies producing the spores
I haven't a clue what that might be perhaps something like hive clean because that would deter any bees from going down there
Is that all rubbish ?
I have summer man flu (cold) and might be delirious
Unfortunately using a top entrance made no difference so that part at least is rubbish
Neither did a false floor to let mummies drop through on to hiveclean powder so that was rubbish as well
Hey ho! it was worth a go at least
No one has said anything about the hygienic response to chalkbrood.
In 1998 I sent 400 colonies to Florida for wintering, under the care of another beekeeper. They came home rotten and stinky with chalk. To this day, the worst chalkbrood I have ever seen. I re-queened with a strain of Carniolan that had been selected for their degree of hygienic-ness by using liquid nitrogen. My God! These bees cleaned up chalkbrood like nothing you have ever seen. In not much more than a month, colonies that had piles of chalk mummies on the bottom board were mummy free. Since incorporating those bees into my program, chalkbrood has all but disappeared in my apiaries. I now use chalkbrood...or lack of chalkbrood...in my breeding program. I see a handful of chalk colonies every summer but that's among more than a thousand colonies and nucs.
I have to agree that imported stock isn't necessary. The hygienic trait is surely present in your UK stocks, and you just have to select for it.
One of my main selection criteria has always been a clean brood nest. I believe this one observable feature can show you whether your bees are dealing with chalk, varroa and any number of brood maladies, plus give an indicator of fecundity and egg viability. I may be fooling myself, but a quick glance sure beats all the other painstaking counting of varroa in brood, killing brood and returning to see if it's been cleaned well, measuring dents in dead varroa's carapace, etc.
House cleaning...hygiene...isn't the same as the hygienic response to diseased brood.
Chalk broods pretty endemic round here, so any hive with a clean, compact brood nest is obviously dealing with the causative agent one way or another, without any/many larvae succumbing.
Lots of chalkbrood in some peoples' apiaries here, too. Some operations with heavy infections. Those with hygienic bees see very little chalk.
Are any of the queen breeders in the British Isles selecting for the hygienic response to brood disease. If not, could that be a reason for high chalkbrood incidence and for the increasing number of EFB colonies?
From Marla Spivak:
http://www.meamcneil.com/Spivak%20I.pdf
http://www.beeccdcap.uga.edu/documents/spivak466.pdf
And from Dave Cushman
http://www.dave-cushman.net/bee/hygenequeen.html
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