Using PDB crystals (paradichlorobenzene) is a chemical fumigation method to prevent wax moth damage in stored beeswax combs. PDB crystals release vapors that are toxic to wax moth eggs and larvae, effectively preventing infestations. Stored combs are stacked in airtight containers or bags, and PDB crystals are placed on top, allowing the vapors to permeate the combs. It is crucial to follow instructions carefully regarding dosage, airtight storage, and airing out equipment thoroughly before use in bee colonies, as PDB is a chemical substance. PDB is a highly effective method for long-term wax moth prevention in stored equipment.