How To Treat Wax Moths [8 Options For Beekeepers]
Healthy bee colonies are good at dealing with wax moths and their larvae. But weak hives don’t have the numbers to watch every corner of their home. In the right conditions, wax worms will infest and destroy a hive in less than two weeks.
Beekeepers are often better to put their efforts into preventing wax moths. But if the hive appears to be under duress, there are various ways to control wax moths. As with most parasitic invasions, chemical treatments should be a last resort.
How to eradicate wax moths in a hive
The best ways to get rid of wax moths are manual removal by hand, freezing, heat treatment, or burning equipment. Other options are insect zappers, moth traps, and carbon dioxide fumigation rooms. Chemical control may be needed if all else fails.
1. Manual removal
Picking out larvae and killing them will help out hives with mild infestations. This simple process is often all that’s needed to fix the problem.
Webbing indicates that larvae are active, so look closely in these areas. Beekeepers should also learn to identify wax moths as there is a range of other giveaway symptoms.
Cutting out comb sections is a better option if it’s starting to look messy with webbing. Once removed, burn the comb to kill any live larvae and eggs. This step will stop a persistent larva from crawling to a new hive and resuming tunneling.
While physical removal of problem areas can help, freezing the drawn-out comb is more thorough. Low temperatures will destroy the larvae and eggs, which are extremely hard to spot.
Once the pest has been eradicated, frames can be brought back to ambient temperature and returned to the hive or stored for next year. Remember to freeze the supers as they may house unwanted wax moth larvae and eggs.
Freezing times to kill wax moth:
|Temperature (°F)||Temperature (°C)||Freeze time|
Always allow time for the equipment or comb to reach the freezing target temperature before setting the timer.
Quick tip: Freezing the brood will kill wax moths at every stage, but it also kills the bee brood.
3. Heat treatment
Beekeepers that don’t have access to freezer space can also use heat to kill wax moths at any stage of development. Research shows this method should be reserved for comb with minimal or no honey (Shimanuki & Knox 1997).
Maintaining an accurate temperature is essential – too hot, and the beeswax melts or sags; not hot enough, the wax moth larvae and egg will survive. To avoid damaging comb, never heat them above 120°F.
Always allow time for the equipment or comb being heat treated to reach the target temperature before setting the timer.
Heating times to kill wax moth:
|Temperature (°F)||Temperature (°C)||Heating time|
4. Burning equipment
No beekeepers want to burn their equipment, but sometimes it’s the best option. This treatment option is best in extreme cases where colonies experience severe infestations. Larvae will have usually destroyed parts of the hive, making them unsalvageable.
5. Insect zappers
Insect zappers are electronic devices that kill unwanted insects like mosquitoes and flies. The commercial ones can wipe out adult moths in large numbers.
Keep in mind zappers won’t deal with the eggs or larvae. Beekeepers can add this weapon to their arsenal with other options on this list.
While smaller, less powerful models are okay, a higher voltage purpose-built zapper is more effective.
Worried your honey bees may get killed by an insect zapper? Check out our article about whether bees are attracted to light.
6. Moth traps
Setting up a moth trap out of the hive won’t kill wax moths in the hive, but it’ll provide a helpful distraction. Beekeepers use this strategy to lure pesky moths to a quick death.
Commercial products are available, but a large soda bottle is much cheaper. Fill it with a cup of sugar and a cup of water. Then add half a cup of vinegar and toss in a banana skin. Finally, hang it from a nearby tree and make a hole about 1” in diameter towards the top of the bottle.
Over the coming days, the bottle’s contents will ferment and entice wax moths to enter the trap. Once inside, they are trapped and drown. Use multiple traps to double down on this approach.
7. Carbon dioxide
Fumigation using CO2 is an option for larger commercial beekeepers. Bees have no adverse reactions to this treatment option which is a huge benefit.
Beekeepers require an airtight fumigation chamber which can be costly. CO2 levels need to reach 90-98% to destroy larvae successfully. These levels are hazardous to humans, so extreme care should be taken. We recommend getting expert advice on following the correct procedure.
8. Hard chemicals
Chemical control of wax moths is a final option if all other methods haven’t removed the infestation.
In the United States, the two approved chemical agents for this purpose.
- Paradichlorobenzene (PDB): The most common option, this fumigant protects stored honeycomb. It shouldn’t be used in live colonies or on comb for human consumption.
- Aluminum phosphide: Available in pellets and tablets, this fumigant turns from solid to gas and is highly effective at killing wax moths, larvae, and eggs.
Warning: Consult a pesticide applicator or trained professional when using chemicals. They are a “restricted use chemical” that can be hazardous to humans.
How to clean a hive infested with wax moth
Wax moths create a mess in the hive if left long enough. Unlike foulbrood which requires extreme measures, wax moths are pests that are more of a nuisance. Removing them from a hive is easier.
- Comb with minor damage can be returned to a strong colony, and they will rework it.
- The hive can be pulled apart in severe cases where few or no bees survive. Remove any salvageable honeycomb, then scrape off cocoons and webbing from the other frames and boxes. Freeze and then bag the equipment for next time.
- Other options for cleaning hive equipment include pressure washing or scorching with a propane torch.
- Frames with plastic foundations require less cleanup, and the colony will rebuild quicker if they have survived.
Can you eat honey with wax moths?
While honey cannot be sold that contains a wax moth infestation, it can be used for personal consumption. Eating larvae-ridden honey won’t appeal to most, so beekeepers often cut away the good sections and feed the affected honey back to the bees. Be sure to freeze the comb first, or reinfestation may occur.