Knocking Down Mites with Drone Comb
Another chemical-free method of lowering the Varroa population in a hive is to use drone comb. Female mites are more attracted to the larger cells in which drones develop. In addition to being larger, the drones take three days longer than workers to develop.
Robert Harvey of Harvey's Honey in Monroeville, NJ (commercial beekeeper, pollinator and supplier of glassware and bees) is shown here holding a frame of drone brood which can be removed from the hive, frozen to kill the mites (and the developing drones), and then returned to the hive for the workers to clean out and the queen to lay in again.
While this reduces the mite population, it also reduces the drone population, which can be a factor if you are raising your own queens. However, this is another control method at the dosposal of hobbyist beekeepers who would like to avoid chemical controls.
by Curtis Crowell)