How can I prevent Wax Moths?
Wax moths are a persistent problem to bees and beekeepers. The larvae feed on debris in the brood comb, tunnelling through the midrib and leaving webbing behind. Before pupating, larvae burrow into wood and spin a cocoon. The burrowing will only cosmetically scar inside surfaces of hive boxes; but, it will severly weaken frames and other thinner wood in a hive. Generally strong, populous hives do not have a problem with wax moths. Weaker hives containing combs without bees, particularly brood comb, are vulnerable to this pest. The best (only) treatment in the hive is to boost the hive's worker population or combine weak hives to prevent wax moth damage.
Frames in storage can be protected by one of three methods. First, wax moths don't like light. Storing the frames, usually in hive boxes, in a manner that the comb surface is exposed to sun light is helpful. Second, all life stages of the wax moth are vulnerable to cold temperatures. You can place the frames/boxes in the freezer for several days to kill off the moths. You should freeze it for several days to make sure the comb is completely frozen. Afterwards, double bag the frames/boxes in trash bags to prevent reinfestation. Third, moth crystals with the active ingredient paradichlorobenzene (PDB) is registered for use with stored equipment against wax moth. Don't use napthalene moth crystals. Naphthalene is more persistent in comb and will harm your bees when boxes are placed on hives. As a fumigant PDB is temperature sensitive, i.e. higher temps, greater rate of vaporization. You'll need to stack boxes containing frames of comb such that they are "air-tight" by taping up any holes or broken/rotten wood and covering top of stack. Apply 3 ounces on a paper towel, wax paper, or other flat material for each 5 deep or 8 medium depth boxes. Use the product in an outbuilding or outside. Remember PDB is a poison, exposure to the vapors could be detrimental to your pets, yourself, and your family. Also, you should air out the boxes before placing them back on a hive. PDB is toxic to bees but quickly dissipates in 2-3 days after removal of the crystals from the boxes.