This will be my first attempt to add a picture to a post, so I may have to edit it to make it work.
We had a weak hive and I did a mite count to check things out. This was a new hive this year from a nuc and it was not treated by us for mites in the spring as we were just getting the hive going. I know that the supplier of the nuc treats his hives regularly with formic acid because I have been on hive maintenance visits with him.
I had to leave the sticky board on for 6 days because I couldn't get to the hive as early as planned, but in any case, I made a count of approximately 192 mites/24 hours (well over a thousand on the board)
. This is obviously a pretty high mite count even for late summer. I had hoped that this hive would finish off one more super for the year and the bee population looked good, but I had to pull the super and treat the hive as I want them to be strong enough to make it through winter (or survive at all).
Interestingly, although my near vision is not great, even with reading glasses on, I could never see mites on bees crawling around the hive. I could see mites on larvae when cleaning off some extraneous comb when putting in mite treatment, but I just could not see mites on bees as I would expect to with this high a level of mites (I am betting they are there, its just they blend really well with bee colors).
Hopefully a couple of thumbnail pictures will show up. Clicking on them should bring up full size pictures.