Brood failing on a few hives, what is it?

[D Coates]

I've got a few nucs and hives that have spotty patterns.  When you look into the comb you can see about +15% of the larva are off colored, amongst the health pearly white ones.  Some of the brood dies (est. 15%) in the capped stage and rattles when the frame is tipped.  I was thinking it was EFB and it would pass but that was a month ago.  Is this Sacbrood or chalk brood (no mummies ever observed), or something else and how do I treat?  The hives are plodding along and unless I can get this under control overwintering will spell their demise.

Any responses are appreciated.

[rwlaw]

I can only comment on chalk brood, had a hive from a nuc that I had picked up that developed it, put em out in full sun & they superseded the queen. The problem went away

[Michael Bush]

So the brood looks brown before it's capped but it gets capped?  EFB usually kills the brood before it's capped.  AFB usually kills it after but it won't "rattle".  Stonebrood might be a possibility.  Sac brood doesn't rattle.  You would see chalkbrood mummies if it was chalkbrood.  They are quite noticeable if you look for them.

http://www.bushfarms.com/beespests.htm#stonebrood

[D Coates]

No.  If it's brown larva it doesn't get capped but it takes a while for it to get hauled out.  Some larva that appear healthy get capped and apparently die in the pupa stage.  While looking at a frame last weekend I flipped it and noticed the rattling sound.  I've seen chalk brood mummies before but I'm seeing none of those.  I'll look into Stonebrood.

[10framer]

are you sure the rattling sound wasn't pollen dropping out and hitting something?  how about some pictures? 

[D Coates]

Positive.  I've heard the pollen sound before as well. When it 1st happened I looked at the frame and realized the noise was coming from capped cells.  I even shook off the bees then lightly shook the frame and it rattled like a maraca.  I'll get some photos this weekend.  From what I've read Stonebrood and Chalkbrood are conditions that either clear themselves up or break the brood cycle for a restart.  If neither of those things occur the queen needs to be replaced.