Checkout the attached photo. It is the bottom board from what was my rather strong overwintered colony. Lots of us have seen a little chalkbrood now and then but this is a lot more than we usually see.
Chalkbrood is a fungus that grows in cool, damp weather when there aren’t enough bees to keep the brood warm. Although this comes from Australia this link does a good job of explaining it.
https://beeaware.org.au/archive-pest/chalkbrood/#ad-image-0
I caused this problem. On April 11th I rearranged the colony to keep it from swarming and to take advantage of the nectar from the meadowfoam which was about to burst into bloom. It’s called the Demarree method of swarm prevention. To do that I moved the open brood up to a top deep box. The queen was in the bottom box with a queen excluder on it. In between those boxes was a super of drawn comb.
Ordinarily it would be a great idea but with the weather we have had for the last two weeks the bees in the top box couldn’t keep the brood warm enough and so the fungus took over giving the larva their chalk-like appearance. The bees did a good job of cleaning out the larva and dropping them to the bottom board.
I’ve read the spores live for 15 years. To minimize the contamination all the frames from the box the chalkbrood larva were in will be scraped, sterilized and rewaxed. The tools needed sanitizing, too. There’s no mention anywhere of risks associated with consuming the honey but I’ll check with Dewey or OSU.
I have to say the hive is very heavy and I’m so curious if I, indeed, get meadowfoam honey. I didn’t think so with so little time for the bees to collect it so far but then it will bloom for another month or so. Meadowfoam is rated a “5” for nectar, the highest rating given. So we’ll see.
I expect the colony to survive….