Beekeepers: Beware of Wax Moths
It's easy to take things for granted in beekeeping when you think you have a strong, productive hive that will just keep on growing and thriving. Things may not always be what they appear though. You can lose your entire hive before you even realize what's happening.
Let me introduce you to the wax moth. Wax moths are jerks. They like to munch on the honeycomb, recklessly tunneling through stored honey and brood until everything is destroyed. A very strong hive can usually keep these moths in check; but for a weakened hive, they can devastate the entire colony within about a week or so.
The Hive Setup
Here’s a short description of my hive setup: it's about a year and a half old, two deeps and two supers, last harvest yielded 25 lbs. of honey. I split the hive earlier this year but due to phenomenal growth, they still swarmed anyways, leaving behind a remnant to care for the now mostly empty hive. And while there were less bees and less activity, those left were nice and busy. New bees were emerging and I was hopeful that the population would be quickly replenished.
Enter the wax moths. We had seen a couple of worms or two on the mite inspection board and killed them right away. And we also found a couple of worms in silky fibrous cocoons on the underside of the hive and got rid of those too. This went on for about two months where we would find a couple of worms almost daily. We didn't see anything when we checked the supers so figured the bees were just cleaning things up.
So Many Worms
One day we started finding more than a few worms...now we were seeing 20-30 itty bitty tiny worms and then the occasional larger ones. Still nothing crazy going on in the supers when we peeked.
And then one evening, my father went to check the top super randomly and saw a couple of larger worms poking through the airflow mesh. On removing the top of the super, he saw a massive amount of squiggling bodies and silky fibers on the frames. He pulled out a center frame and the sight made him ill. There were hundreds of small worms riddled throughout the frame. The surrounding frames looked equally scary.
He called me and as it was getting dark and said we would need to get down and dirty the next day to see how bad things were. The pictures he forwarded were the things of nightmare. Neither of us slept well that night, worrying about the damage done and wondering if it was reversible or not.
On opening the top super the next day, my heart sank. It was even worse than the pictures showed. As we removed each frame, box by box, it was clear that the hive was pretty much destroyed. It appeared that the moths had worked their way up from the bottom of the hive, destroying the brood frames first and making their way up to the supers. Most of the bees were congregated on the top super and the bottom brood box and there were a lot less bees than there had been the week before.
We had difficulty in spotting the queen in the clump of bees that seemed like they didn't want to move away from one corner of the bottom brood box and with all of the moving things around, I didn't want to disturb them any further lest they all fly away entirely. The frame closest to them had the least amount of damage with only a very small part affected by the moth larvae. I was able to remove the little bit ruined and placed that one frame back in the box. This was the only frame that was relatively intact and still had clean stores of honey in it. I saw a little brood here and there throughout the frames that were removed but those were only a handful of mostly drone cells.
We packed up the ruined frames and placed them in garbage bags for the freezer. We are hopeful that the after freezing to kill the remaining larvae, we will be able to salvage some of the comb and honey.
There are very few things as heartbreaking as losing an entire hive, especially in such a short amount of time. You start asking yourself questions like, How could this happen? What did we fail to do? Did I miss some serious signs that things were very very wrong?
At this point, I can look back and realize that we should have gotten a little more serious about managing the hive once they swarmed. It was just way too big for a relatively small amount of bees to care for. Once the moths moved in, the bees were overwhelmed by their numbers and eventually couldn't fight them anymore. It would have been much more manageable for them if we had removed the two supers and just let them concentrate on building their numbers back up.
We had also not really noticed an unusual amount of mites prior but taking some preventative measures would have helped keep them at bay. Lemongrass and spearmint are solid deterrents and I'd much rather go with natural repellents rather than harsh chemicals. It's also good to note that moths don't like mint either so it would be a win-win!
If this had been a wild hive that was suddenly wiped out, I probably wouldn't have even noticed the reason. But now that I've become so invested in caring for the bees, it's more of a personal loss when disasters like this strike. It's completely preventable, now that I know what to look for.
Yes, it's a learning experience and something that can't really be entirely appreciated from reading a book or watching a YouTube video. And now I can advise others so that they know what to be wary of too. And I am definitely more motivated to make sure I can do all I can to protect my bees and help them thrive.
Questions & Answers
Mint, spearmint, and lemongrass as a natural deterrent; how are they applied/used?
Thanks for the question! I usually use essential oils and rub a few drops on the underside area of the hive as well as on the inside of the top lid, maybe every other week or so during the warm months. My dad swears by planting mint around his hives and then I know that some keepers will throw a little dried lemongrass in their smokers when they work in the hives.Helpful 1
How common are wax moths in North America?
Lesser wax moths, as well as greater wax moths, are found around the world, though the greater wax moths prefer warmer climates. We have a fairly large amount of them in our area of NA and they are attracted to honeybee colonies, so you'll usually find them hanging out outside the hives, trying to figure out a way to lay their eggs nearby.