Back when mites were starting to be a problem, "they" (whoever they are- the experts I guess) used to say that if you could see the mites on the bees your hive was already in trouble. Well, I've seen a lot of mites since then, unfortunately, but I have been lucky not to have lost any hives to them. I think hearing that scared me so much that I have always treated mites very aggressively. If those were my hives I would not wait- by spring they might be dead.
Put your sticky boards in for 18-24 hours. If you see 59-187 mites when you check, then you need to treat or your hives may be at risk.
The time to treat is coming up- in my area I would be treating as soon as I pulled my honey- around here that will proabably be in August this year. If I had a heavy infestation I would start now with a drone frame and try to get a couple of cycles before the queen begins to slow down, then hit them hard with whatever other treatment(s) I intended to use.