Source: Wax Moth DPI by Doug Somerville
The greater wax moth (Galleria mellonella) and lesser wax moth (Achroia grisella) are major pests of stored or unattended combs. The greater wax moth causes the most damage; however, the lesser wax moth is generally more common, and can also cause significant damage. The two species tend to coexist, and are frequently found in the same location.
The primary concern for beekeepers is how to adequately store combs without them being destroyed or damaged by the larval stages of the moths. Destruction or damage to combs can also occur within weak hives which have died or have low populations. The presence of an adequate number of adult bees will prevent wax moth damage. It can be assumed that wax moth will never be completely eliminated from an apiary or storage shed.
Control of Wax Moth – Freezing
All life-cycle stages of the wax moth, including eggs, are killed by freezing at the following temperatures and times:
- – 6.7C at 4.5 hours
- -12.2C at 3 hours
- -15.0C at 2 hours.
It is important to commence timing of this treatment only when the hive material or apiary products have reached the recommended temperature. A number of hobby beekeepers have purchased small freezers and find freezing an excellent means of protecting their combs.
After freezing, the combs should be stored in a moth-proof environment to prevent re-infestation. Sealed, strong plastic garbage bags provide a good insect-proof storage environment.
Combs that have been frozen and then placed in untreated supers for storage are immediately at risk to infestation because the supers may contain wax moth eggs. It is best to treat the super and combs and then place them together in a sealed plastic bag.
Provide a light source
Wax moths hate the light. So supers can be stored on top of each other, with a light source at the base, shining up through the stack.