I know that I've heard some other people here say that they only treat for mites when they have a problem, and I'm wondering how you know you have a problem. I've never seen a mite on a bee this summer, but after building oil traps for SHB I saw some varroa floating in the oil within only a couple of hours of changing the bottom boards for the traps. This is not good, but I should have known.
Anyway, how do YOU monitor for varroa mites?