Alas, those are Varroa mites. Not helpers, but blood-sucking (or the bee equivalent to blood: hemolymph) aliens that are causing quite a problem for beekeepers.
Obviously such treatments are only useful for commercial beekeepers - not the wild / feral colonies. The problem there is that it means commercial beekeepers have to keep using the same chemicals forever (or until the mites develop a resistance), as they'll continue to get re-infestations coming into their area.