Protecting against Wax Moth.
The only protection against wax moth is to keep your colonies strong and healthy. If the colony is failing, consider uniting it with another one (after checking it has no disease). Protecting stored comb is difficult. Wax moths wont usually infest clean comb that has no pollen or other debris in it, and they never (in my experience) attack foundation. They need used comb that has ingredients other than wax in it - they will attack, for example, comb with honey in it, or comb containing pollen, brood, old brood remains, cacoons and so on.
Stored comb.
If you are storing comb, spray them with Bacillus thuringiensis. This bacterium can be purchased from bee supply stores and, when mixed with water and poured into a hand garden sprayer, can be sprayed easily onto the combs surface. The bacterium will protect the comb without fail and wont contaminate anything except the wax moth larvae. This treatment usually lasts throughout the winter. It is quite a task if you have thousands of combs to treat but, for the small producer, it is very cost effective.
Freezing combs kills all stages of the pest. When you store comb over the winter in a shad, keep the boxes in a cool, well ventilated place with a spacer between them to let in light: Wax moths shy away from light.
In colder climates you can store your supers on top of your hives with a mat or escape board between them. This will allow limited bee access but will keep the supers cold.
Whatever you read elsewhere, don't use PDP (para-dichlor-benzine) crystals. They work, but have been shown to be carcinogenic. Remember, beeswax is a chemical sponge that will soak up just about anything. Its best not to fumigate combs for the same reason. It will contaminate the honey if you try and use the crystals on honeycomb.
Stored Pollen and Propolis
Stored pollen and propolis that has been harvested will also be attacked by wax moth, and for this reason should be sealed tightly in storage. Pollen traps placed on your hives should be emptied at least twice weekly. I well remember selling what I thought was a barrel of propolis to a buyer who later found he had bought a barrel of maggots.
Remember that, if you do find moth damage in your hives, look for the reason why the moths have managed to cause this damage. It could be because of disease.
