Re: Vaporizing in February
OAV does not have hard and fast temperature rules like formic acid. However, to be effective, the bees cannot be tightly clustered, so yeah, above 40°F would be best. OAV can be applied anytime honey supers are not present. A treatment applied now will kill all of the so called phoretic mites in the hive. If your hive already has capped brood, you may wish to perform several treatments approx. five days apart. From now till the end of summer the bees should be able to out breed the mites so usually the next treatment will be late summer. This of course assumes the initial mite load is near zero. YMMV.
Thankfully, the bees are smarter than I am. They are doing well, in spite of my efforts to help them.