I’ve gotten behind on updates, but have visited the OSVC hives 4-5 times since the last report to do mite counts and feed them; so, this update will be more generalized than others.
Hive 4:
This hive had a 4% mite load (10/8/21) before the last formic pro treatment. I applied one pad on 10/8/21 and it brought the mite load down to 0% (10/18/21). I was afraid that this last and final treatment may have killed the queen; however, I did finally find her, and a small amount of brood. I will not be adding the second pad to complete a full course of treatment because they are now below threshold.
After this year’s losses due to formic pro (of both queens and high amounts of worker bees), I will only be applying formic pro to top bar hives one strip at a time, and when day time highs are below 84 degrees.
This hive has been able to put on some weight since mid-summer, but will still need some supplemental feeding.



I fed Hives 3 and 4 crystalized honey during formic treatment, because honey does not absorb the formic acid like sugar water does (this is why you can not feed during formic acid treatment).
Hive 3:
This colony lost it’s queen during Tx, I think. The mite load before Tx was 4% (10/8/21). There were a couple emergency queen cells. One that a queen emerged from and one that was torn down. I found the virgin queen. I can either see how it plays out (I have a hive a mile away with drones), or I can install a queen from Melanie. The likelihood of a queen mating this late in the season is low, but I’d kind of like to see if it works out.
This hive had some capped brood and has also been able to add some more weight.
There were quite a few dead mites on the bottom of the hive, indicating that the treatment was effective at killing a large amount of mites.

Hive 2:
This hive had a 7% mite load on 8/16/21 and began receiving oxalic acid vapor treatments (thanks to Craig) (all other hives had been treated with formic and had a 0% mite load). The mite load gradually went down to 6% on 9/29/21. On 10/8/21, 2% mite load. On 10/18/21 it was down to a 0.66% mite load, below threshold. This was great to see after all the mite challenges.
This colony has a decent amount of brood. The queen was seen. They still need to put on some weight before winter.

Hive 1:
This hive had a 2% mite load on 10/8/21. It has received a couple oxalic acid vapor treatments since then. I assume it is now below threshold. I did not retest every hive because they have endured so much testing and treatment this season. I think this hive has likely maintained threshold or fallen below.
I saw the queen and a good amount of brood going into winter. Like the other hives, this hive also needs to put on some weight before winter. I am feeding them a fall sugar syrup, honey, and fondant in the back of the hive. The bees have a buffet to choose from. They are taking the sugar water most quickly. I thought this was interesting. Maybe because it is more easily accessible? While crystalized honey and fondant require some water to move and store?
General:
Hives 4, 3, and 1 had 0% mite loads after their formic pro treatments this summer. Two of the hives had to be requeened. Mite loads then crept back up and honey stores plummeted. My theory is that they were weakened from the treatment, were robbed, and then picked up mites during that process. This all happened during the time of the season when robbing is particularly bad. Reducing entrances after treatment probably would have helped with this problem.
I’ve never experienced such a struggle in keeping mite loads down, and subsequent queen and bee losses from formic acid treatments. My hypothesis is that we had large vibrant colonies throughout Albuquerque when the large amounts of rain came. More robust colonies means more mites. With the combination of drift and robbing, I think it made it difficult to keep mite loads consistently low.
Formic Pro is a newer formulation and I wonder if it’s changed in strength or dispersal since it first came out. I know it is different from MAQs, in that it was designed to release formic acid more evenly during the duration of treatment. This is frustrating to us beekeepers who have used formic acid for some time with great success; and now see large amounts of queen loss etc and have to adjust our sails. I guess thats beekeeping!
I now have an oxalic acid vaporizer, protective gear, and training from Craig…
I gifted all hives with some lemongrass fondant for the winter.