How to prevent invasion and treat infestation
Bees make so many useful and delicious products – honey, wax, propolis, royal jelly – it makes sense that humans aren’t the only species that want to access them. But unlike humans, who tend to their bees and look after them in exchange for honey, other species simply invade and destroy.
The Wax Moth is one example. These creatures feed on beeswax, pollen, the remains of larva, and other leftovers in the hive. If you or your bees don’t deal with them, they can damage brood comb and eventually destroy your colony. If you’re not careful, they can also demolish comb stored over winter, wasting months of your bees’ work.
If your hives are strong and healthy, the bees will usually deal with Wax Moths on their own by ejecting any larvae. If they’re weaker, they may not be able to keep up with this task – that’s where you come in.
Here’s our guide to identifying, preventing, and eradicating the Wax Moth:
What is a Wax Moth?
There are actually two main species of Wax Moth – Greater and Lesser. Although the two types look slightly different, they cause the same damage to hives, and they’re treated in the same way.
The Greater Wax Moth is mottled grey in colour, and reaches around 5cm in length. The Lesser species is smaller, slimmer, and paler.
Both species enter hives through unguarded entrances, then lay eggs in cracks or gaps in the hive. When the eggs hatch – which can take up to 5 months in cooler weather – the larvae feed on the beeswax, burrowing under cell caps and leaving a sticky, spider web-like substance behind them. Left to their own devices, they will damage honeycomb and brood comb, causing problems with your harvest and with bee larvae.
On the lookout
Keeping a close eye on your colony is one of the most important jobs a beekeeper does. During your regular hive inspections, you should be looking out for any signs of Wax Moth infestation.
Signs include white webbing and cocoons, disintegrated comb, bald patches in your brood, and dark-coloured, cylindrical faeces in the bottom of the hive.
Preventing hive problems
Prevention is almost always better than cure. Keeping your colony strong and healthy helps prevent Wax Moth infestation, because the bees will generally find larvae and eject them from the hive before they cause damage.
You can help guard against by making sure your hive roof fits well so there are no gaps and cracks, and thinking hard before you add a second entrance to the hive. This gives the moths fewer opportunities to enter and lay eggs.
It’s good practice to keep your hives clean, because the moths feed on discarded and unused beeswax and other hive debris. Remove unused frames, take out burr comb and propolis build-up, and sweep out debris in the bottom of the hive.
Safer comb storage
Bees do not guard frames of brood or honeycomb stored over winter, so they’re particularly vulnerable to Wax Moths.
Avoid infestation by freezing your frames for a day or two before putting them into storage – this kills off any eggs that may be hidden inside. Keep your stored frames sealed in a plastic bag once they’ve been frozen.
Moths like dark, warm spaces, so keep frames in a light, cool area if possible – avoid darkness and warmth.
Sometimes, all the preventative measures in the world just don’t work, and you end up with a Wax Moth infestation. If this happens to your hives, burning the affected equipment can be the easiest way to get rid of the issue, but there are other options.
Clean out all frames, making sure to remove any visible webs and larvae, then freeze each frame for a day or two. While frames are being frozen, clean the inside of the hive thoroughly. At this point, it’s a good idea to use an insecticide spray to make sure every moth and egg is eliminated. Make sure you use a bee-safe spray. Once everything has been cleaned, frozen, and sprayed, you can start building up your colony again.
Like most beehive invaders, Wax Moths are more likely to cause problems if your colony is weak. Keeping your bees strong and healthy is your best defence.