So I did sugar rolls on the other colonies I treated, one of which was at 10% and the other at 9% when I treated them. Today the one was at 3%, and the other was still at 9%. 2 of the FormicPro doses I used were from the same batch, and the third was from a different batch, and it seems oddly coincidental that 2 of the hives had no improvement and 1 did. I'm thinking something may have been wrong with that one two-pack of FormicPro.
I was wondering if the mites that were under the caps became phoretic or dispersed after all of the brood hatched. I had a somewhat interesting experience this summer when I caged a queen & gave them a brood break, mite numbers soared, i.e.2/100 before brood break, 15/100 3 weeks later. Obviously, I treated them promptly & the numbers went down. The only thing that came into mind was that the all of the mites under capped brood were born in a 3 week period, causing mite numbers to soar. Anyone else had this happen?
I've had this happen before, but all three of these colonies still have a little bit of brood, so I don't think it applies in this case.
Yes, that mite-under-brood timing is THE main challenge we have with any mite treatment method. What is interesting about this particular case is the use of FormicPro and results showing it being ineffective. Formic supposedly permeates caps and able to get in the cells to impact mite-under-brood. In this case it did not work as expected. Could be various reasons why. Low ambient temperatures at the time it was used, resulting in a slow formic release below the lethal level needed to impact the mites would be a primary guess.
I actually treated these colonies in higher temperatures than I have ever used FormicPro before, so that's not it.
A migratory infestation from some other crashing hive(s) nearby is also very possible considering the time of the beeyear calendar this is occurring.
It is not unusual to have clean hives in late summer, early Fall, and come back later to find sky-high mite levels. Usually, the cause is some other colonies nearby crashing and the absconding of infested bees drifting into the clean colonies or/and robbing of the crashing hives by the nearby strong clean hives. Those nearby crashing colonies could be feral or managed, makes no difference. Hence, the suggestion that when found containing (bag/freeze) such a terminal colony is usually the best course of action - when taking a holistic perspective of the Apiary (all hives in the area).
This could be a contributing factor, as I suspect this is what happened that led me to treat. Most of my colonies were hovering around 1-3% mites at the end of July and in a matter of a couple weeks these 3 colonies were up near 10%. Interestingly enough, I had another colony at almost 4% at the end of July and their numbers went down to below 1% as the other colonies skyrocketed, which seemed odd. I even checked them again to be sure their numbers weren't a fluke. I was not able to get into that colony to check their numbers today, as it started to rain, but I'm curious where they are.
So I'm going to call around and see what treatments are available locally and at what prices to see what I want to do. If it was just the 22% colony I was dealing with, I'd call it quits and bag them up, but with at least one more colony that needs treating, I may just treat them too and see what happens.
