Oxalic acid and glycerin for varroa mites
“For beekeepers who treat for varroa mites, oxalic acid has become the default favorite miticide. It is inexpensive, a natural component of honey, safe for bees when used as directed, and is drop-dead effective. But being beekeepers, we can’t agree on anything, so the disagreement about how to apply oxalic acid rages on.”
Link to the Randy Oliver’s paper here.