Requeening to control chalk brood

[PeterP]

When you requeen to control chalk brood are you seeking a bee that is resistant to the fungus or a hygienic bee that cleans out the infected larva to reduce the spread?

Regards Peter

[Allen Dick]

Chalk brood is everywhere. Chalk brood susceptibility is genetic and changing to a resistant queen will clear it up.

[Countryboy]

So what traits do you lose when you select for resistance to chalkbrood?

I have a pretty simple selection process for breeding queens. Right now I have about 75 hives. In the early spring, I will pick out 3 or 4 of the strongest hives, that are not miserable mean.

I've been doing this for 5 or 6 years now. For the most part, the only new genetics I bring in are from swarms, or from open mating with primarily feral hives. I have bought a handful of commercial queens, but won't graft from them until at least the following spring if they are a super strong hive. (It is uncommon that I find a commercial queen that is stronger in early spring than my locally adapted bees.)

About 5% of the queens I raise will be miserable mean, and 5%-10% will accumulate a pile of chalkbrood at the hive entrance. If it's really bad, I do end up requeening wiht another queen I raised. Usually I just live with it. Some hives seem to clear up chalk on their own.

I figure there are a lot more important things than worrying about a few chalkbrood mummies.

[Allen Dick]

I have to assume then that you have never seen hives with 30% chalk?

I also assume that good chalk control indicates hygienic characteristics.

[PeterP]

I started 5 years ago with 2 Russian carnys and have introduced a couple of carny's from California. Plus a few queen cells from a local Ontario side liner. The local commercial/side liner has mostly Quebec Carny bees. He would provide most of the drones. I don't know how much of the original hygienic traits of the Russian's remains but they do ok controlling mites. I treat with formic in September and oxalic in November. I wintered 10 hives and 2 nucs last year.

I was hoping hygienic for mites would also carry over for chalk brood. I select from my most successful dark (Carny's). I assume/hope what ever triggers mite damaged larva removal would also work for chalk. Usually I have 2 hives that get infected. same each year. I suspect they have a load of spores and when temps are right for the fungus it gets started. A minor case reduces growth so I don't have to do swarm control, except this year one recovered enough and swarmed because I didn't watch it closely. It seems 10 hives is my limit for managing things given my time commitment and knowledge.

Regards Peter

[Countryboy]

I have to assume then that you have never seen hives with 30% chalk?

No, I've never had to deal with chalk that bad. I've seen pictures of Australian bees that had extreme cases of chalk once the hives were here in the US.

If I see 15-20 chalk mummies on a landing board, I consider that to be a bad case of chalk.

[Allen Dick]

If you think about it, it seems to me that any hive that does not identify and remove dead larve before they become mummies is not hygienic.

[Allen Dick]

What I will probably do with those two hives is shake them through an excluder into other smaller hives and eliminate the queen and the drones