They can enter the hive through the unguarded hive tops if there isn’t a protective screen in place. They will lay eggs in the cracks of frames and other areas where bees cannot reach. When the eggs hatch, they will tunnel through the wax comb, under the caps, leaving behind a mess of webbing and excrement. They feed on the wax and brood castings.
A strong hive can keep wax moths at bay, however, a prudent bee keeper will want to help their bees by taking preventative steps.
1. Use a top screen. This will help not only prevent moths from entering the top of the hive, but will also keep robbing bees hornets out.
2. Set traps for the wax moths. I found this idea online:
3. Freeze your frames. When your frames are not being used, they become increasingly vulnerable. I place mine in large plastic ziplock bags (which I can reuse) and place them in the freezer. They should be allowed to have a hard freeze for at least 48 hours to kill any eggs that may already be in them. After that time, you can leave them in the freezer if you have the space, or remove them. Take steps to prevent more eggs being laid in them by wrapping them in cloth, storing them in hive bodies with a type of moth ball, or getting something like a Crystal Drawer and using para moth.