I've read that GUARDSTAR used as a ground drench kills the larvae, disrupting the reproductive cycle. The active ingredient in GUARDSTAR is Permethrin, at 40% solution. The pint is priced comparatively to other products using Permethrin, but the quart from bee suppliers is over a $100, compared to about $40.00 from a comparative garden center product, called 38 Plus, that uses a 38% solution of Permethrin .
However, I don't want to use chemicals, especially these that have immune and nervous system problems associated with them, so I am trying other methods.
I soaked the ground around the hive last night with a gallon of bleach in a five gallon container of hot water. The bees came pouring out of the hive, but none were harmed by this. I ventilated the top of the hive to make sure there was good air flow so that fumes would not be trapped in the hive. I am also going to try Lye as a ground drench.
Comb fouled by hive beetles can also be cleaned in a bleach solution and the bees will use it after 24 hours have passed.