The varroa mite populations have been building all spring while the hives have been building populations befor the honey flow. This means that mite carried viruses are also building. This is a good time to knock down the mite populations through applications of either oxalic acid vapor or MAQS application. In fact in the past week I have seen a few drones with deformed wings which is a BAD sign.
Use only MAQS or oxalic acid treatments while honey supers are on the hive. These are naturally occuring compounds and won't negatively affect your honey. Other treatments WILL negatively affect the honey. DON'T use them.
If you treat the hives now they won't need another tretment until after removal of the honey supers in mid-August. It also keeps the mite populations in check and will improve the effective of your post honey removal treatment.