( see video link above)
Using the ProVap 110, you can see the initial burst of Oxalic Acid, a slight delay as the unit drops in temp, then a secondary blast of OA when it resumes temp. Vapor cloud remains suspended for a surprising length of time, around 10 minutes obscuring visual of the comb - about 18 minutes for it to totally dissipate.. Top and bottom entrances are totally open. This OB hive has been occupied for 2 seasons, overwintering successfully with only OAV treatments in late fall & winter when likely broodless for mite control. Western Washington State, AG zone 7.
Temp is mild, about 55-60 degrees F, cluster is naturally loose. Some bees are lightly flying. When it's colder, you won't see any bees on the outer and lower comb.
Thought you might like to see the unit as it dissipates OA within the hive.
I also had another hive I treated where some bees, as they typically do, are temporarily pushed outside the entrances while the treatment is in progress.
I saw a bee with an odd very light spot on it and took a quick snapshot to look later on the computer screen. I was surprised to see a very old, dead mature apparently decomposed mite on it's thorax. This hive had no treatment or management all year. The strain is vigorous and tolerated mites well, but has little natural tenancies to control mite populations on it's own, as many of my other lines will do. (Mite populations will eventually flourish without some management) Why this mite is dead and still attached is really beyond me. Unless they are biting the mites or are doing something I am not aware of.
This was not the only dead mite I saw on the bees, there were a few more just like it. I'd love to dig into this hive to see what's up, but can't do it this time of year. It is full of good looking young bees though, I know that much.