What Causes Wax Moths in Bee Hives?
Finding wax moths in bee hives can be very upsetting to any beekeeper. Have we failed our hives? Why did this happen? Thankfully, it is rather easy to help our bees fight against them. Learning how to deal with these pests in the hive is necessary for good beekeeping.
Wax moths are attracted to all beehives. The scent of beeswax, honey, pollen and other hive odors lure the moths inside.
However, not every hive will suffer a major attack. A colony with a strong population is well equipped to throw those pesky moths out!
Maybe you have a beehive with a smaller population than you would like? The smaller, weaker honey bee colonies are at the greatest risk from moth damage.
The population strength of any beehive varies throughout the season. Smaller colonies such as a new hive started from buying bees in a package will need time to grow.
Do you have a strong colony that was split into 2 halves? When you split a bee hive, failure to include enough bees in each part could lead to moth problems.
Any time you mix warm weather conditions with weak hives, there is a potential for problems caused by a wax moth infestation.
What Is A Wax Moth?
Galleria mellonella, the Greater Wax Moth and Achroia grisella, the Lesser Wax Moth are two common beehive pests.
Both types of moths are attracted to the hive by odors. They are most active after dark and often enter the beehive at night.
It is near impossible to keep moths out of a hive. In my opinion, it is an exercise in futility to try. Adult moths do no real damage but they leave behind wax moth eggs.
Moth Larvae – Wax Worms – the Real Problem
If the population of the hive is not large enough to guard all of the comb surface, adult moths lay eggs on the comb.
Moth eggs can hatch in 3 days during warm conditions. These wax moth larvae (called wax worms by some beekeepers) are the true pests.
Wax Moth larvae are very small white grubs. To the untrained eye, they don’t look much different than bee larvae.
Then, they begin to eat and grow and grow. By now, the adult moths may have left for another site.
Or if the colony is very weak – adult moths stick around taking advantage of the free nesting area.
Many beekeepers put out “moth traps” to try to lessen the number of adult moths entering beehives.
These traps are commonly home-made with many different “bait” recipes in use. Perhaps you can experiment with bait recipes.
But don’t expect traps to be the complete answer to moth problems.
What do Wax Moth Larva Eat?
Older, darker comb that has been used to raise baby bees and hold pollen is very attractive to the adult Wax Moth.
This is the type of honeycomb that provides the most nutritious food for the moth larvae. Moth eggs laid in this region will be nearest to their food source.
Wax Moth larvae eat beeswax, the remains of bee larval cocoons, bee cocoon silk and bee feces in the cell. All of these are present in older frames of comb.
Bee cocoons are the materials left behind by a developing honey bee. Any comb that has had bee brood, will be more attractive to wax moths.
This preference for used comb is why problems develop near the brood nest of the hive. But wax moth larva can live on pure beeswax.
This is another reason to try to keep honey bee brood out of your honey supers. This can be accomplished by using a queen excluder.
Evidence of Wax Moth Damage
How do you know that you have a moth problem in your beehive? Believe me, it is easy to see.
Have you inspected a weaker hive only to find a webby, wormy mess?
No this is not the work of a family of spiders, you have been visited by wax moths. Now, the wax worms are rapidly growing while they destroy your comb.
Even with advanced damage to the comb, the honey bee colony may be trying to save the hive.
You may find a few bees trying to hang on or the colony may already be dead. Did wax moths kill your hive? Yes and no.
Life Cycle of the Wax Moth
Eggs laid by an adult Wax Moth become voracious larvae. Eating and growing day by day. A strong bee colony will chase the adults and remove moth eggs.
However, the adult bees generally do not remove moth larvae. So any eggs that are laid, may have an opportunity to develop before the comb is cleaned by the bees.
The larval moth stage can be completed in 19 days from hatch in warm weather.
When larvae feeding stage ends, larvae spin white cocoons for the transformation into adults.
They will often eat away wooden surfaces in the hive creating a wavy surface and causing damage to the wooden parts of the beehive.
Beekeepers who use plastic foundation have less of a clean up job on wax moth infected frames. Those of us who prefer beeswax foundation need to keep extras on hand.
The cocoon stage lasts about 14 days before adult moths emerge and begin the life cycle again
Do Wax Moths Kill Bee Hives?
It is a common occurrence for a beekeeping student from my online beekeeping class to tell me “My hive was killed by wax moths”.
This is upsetting for any beekeeper and especially for those new to the hobby.
Wax moths don’t normally cause bee colonies to fail. They are just a symptom of another problem the colony has.
In reality, wax moths seldom kill a hive of honey bees. Finding wax moths in bee hives is an indicator of another problem – why was your colony weak?
How to Prevent Wax Moth Damage
Keep strong colonies will good population size. Do you have a lot of bees in the hive? Are there enough bees to cover most of the comb surface?
They must have a large enough population to prevent adult moths from laying eggs. This is especially true during the warmer months.
Don’t put too many boxes on the hive at one time if the population of the hive can not patrol the comb.
Is your queen bee is failing – causing the hive population to drop? It may be time to order a new one so you will have plenty of new bees being produced.
How Do You Know If You Have a Wax Moth Infestation?
How does a beekeeper know if they have a problem with wax moths in the hive? The easiest method of detection is the presence of webbing and tunnels in the honeycomb.
Leaving behind noticeable tunnels with a “spider-like” webbing. Wax worms continue to eat until all the wax has been consumed. Leaving a webby, mess for the beekeeper to clean.
Seeing an adult moth or a few moth larvae is no cause for panic. Even a strong colony may have the occasional moth or wax worm.
Wax moth larvae can be found crawling on the comb surface. The larvae are easily confused with Small Hive Beetle larva, another bee pest.
Larval feces (small cylindrical black pieces) can also be seen on the bottom board.
Strong Colonies Repair Wax Moth Damage
When a honey bee colony has a minor problem with moth infestations, the bees will clean and repair the comb.
You do not need to throw away good comb with minor damage. A strong colony will repair it for further use.
How to Get Rid of Wax Moths in Beehives
- keep all colonies as strong as possible
- do not give the bees too many boxes at one time
- check colony population periodically throughout the warm season
- if a large crowded hive swarms – consider reducing the number of boxes if the population drops too low.
Wax Moths in Stored Honey Supers
One of the biggest mistakes made by new beekeepers is improper storage of honey supers. Moths will destroy your drawn comb.
After harvest, freeze any combs for 2-3 days, then place them in an airtight storage bin or plastic bag. You must freeze them first!
Freezing kills any wax moth larva and eggs that you cannot see. After freezing, placing them in a tight storage container.
There are some chemical approved for moth control. One that has been in use for years is – ParaMoth. This should be safe but some beekeeper are reluctant to use it.
Another product – Certan was removed from the market for bees but supposedly is becoming available again.
If you fail to store your honey supers of comb properly, you may find a nasty surprise in the Spring.
Wax Moths Are Not a Beekeepers Enemy
While they may cause many headaches for beekeepers, wax moths are not an enemy of honey bees. They are a natural part of the bee ecosystem.
In the wild, wax moths enter an abandoned colony and clean up old comb. This leaves a clean disease-free cavity for the next bee swarm.
Use good honey bee management practices to deter wax moth infestations in your colonies.
If you live in a region with cold winters, you will only have to worry about wax moths during the warm season.
Our beekeeping friends in warm climates must be vigilant year-round. Otherwise wax moths will move into their beehives and do damage if they can!