B401 previously known as Certan is the only known preventive against Wax Moth.
A form of BT or Bacillus Thuringiensis formulated to kill the larvae when it tries to feed on the comb.
Use 1-19 water in a pressure sprayer will treat 120 frames in storage. Will not harm you, honey or the bees.
Well worth the expense to keep those valuable frames free of damage.
Not for sale in Canada