foulbrood

noun, either of two bacterial diseases causing the death of honeybee larvae in the comb (OED)

“You were just talking about burning a hive. Why would they do that?”
“If you get foulbrood, that’s the only way you can kill it.”
“It’s kind of a disease of the bees?”
“The brood all die. And the problem is, you see, if another bee comes into that hive or one of them bees go to the next hive, you got it in the next one.”