Like most bee pests, mold can take over once a colony is weakened or on the decline. Mold can appear to drive a healthy colony out, however, a healthy colony can keep the mold from taking over.
Once you see mold, the bees have become too weak to regulate the air flow and thus keep the moisture down within the hive. Usually mold is found on dead-outs that were caused by over-winter starvation or disease. It can also be found on poorly stored honeycomb.
A failed bee colony is a perfect location for mold to grow. It’s got contained moisture, food, and since mold can grow in most temperatures it’s got the right conditions to take over your good honeycomb.
4 Steps to re-use your moldy honeycomb:
It can take the bees several days to clean up the frames, however, they’ll remove all evidence that the mold ever existed and will have comb to utilize for honey storage or brood production.