I've had some people request I follow up with the FormicPro treatment I'm doing, and I thought I'd go through the whole treatment for the benefit of anyone who may be considering using the product. This is the hottest temperature I've ever used FormicPro in, so we'll see how it goes.
During my last round of inspections, I found two colonies in my apiary containing some bees with deformed wings. I did sugar rolls in both colonies, and both had EXTREMELY high counts (I'm talking like 50 mites in each roll). I also had another colony that I attempted to do a German mite trapping treatment on about a month ago, but the queen kept escaping the queen excluders, so I decided to treat that colony as well, since their counts were similar to the worst-looking colony about a month ago (around 4.5%).
I purchased two packages of FormicPro from my local farm store. FormicPro is an organic miticide with the active ingredient of formic acid; each package treats two hives. I have used FormicPro, along with its predecessor MAQS, before with good success several times, and once without good success, when I had one package fail to reduce my mite loads appreciably in two colonies. I chose the product for this particular treatment because of the severity of the mite infestation and the potential for deformed wing virus, and because I still have some honey supers on. Formic acid penetrates brood cappings, so only one application is enough, and formic also takes out any weak bees, and I want the product to kill any bees that may have a high virus load so any DWV doesn't spread further. While FormicPro is supposed to be super-safe, I don't feel comfortable eating or selling any honey that has been exposed to a chemical treatment of any kind, even an organic one (and especially one with a smell this strong), so any honey that is in the hives for the treatment will be left on for winter or be spread around the apiary.
The instructions say that the ambient temperatures should be between 50-85F on the day of application, and it should never be above 92F for the first three days of the treatment period, which is two weeks total. I have used FormicPro when the temps were in the 60's and 70's, but never when it's in the 80's. To prepare the hives for treatment, I removed any honey I wanted to take off for myself a few days ago, and today I removed the entrance reducers, closed any top entrances, and put the varroa boards in the bottom boards. When I actually apply the treatment, I always wear nitrile gloves and my solid suit to avoid accidentally getting anything on my skin, as the formic acid is very corrosive. Each hive gets two strips laid on top of the bottom brood box. The bees react immediately to my laying the strips down, fanning and moving away from the strips, and as soon as I put the next box on, those bees fan as well. When I left the apiary, all three hives were bearding and fanning, which is normal in my experience.
As I mentioned, the treatment period is two weeks, during which time I'm not supposed to disturb the hives in any way. I'll keep everyone posted on how the bees are acting and the treatment results at the end.