Wax Moth Infestation

Greater Wax Moth Infestation (Galleria mellonella)

I didn’t have my camera, so I can only describe the extent of the infestation.

Upon taking off the roof I was presented with a few hundred wax moth larvae in the polystyrene that I used in the roof. I could see larvae spilling out of the two Porter bee escapes in the crown board.  I was met with resistance when trying to prise off the crown board – it was stuck down with a very sticky and thick cotton wool like fibre.  This cotton wool like web was 1cm thick over the top of all the frames.  It was full of larvae and so thick that there was no way the bees could get through it.  Upon trying to pull out a frame I was met with this thick cotton wool web down each seam of bees and in each frame. The frames were beyond repair and I chucked them in a pile to be burnt. By this stage there are thousands of larvae crawling around which I slice through in the hope that they do not enter my other hives.  Ten minutes after I started taking the hive apart, I even find them on my smoker which was on a spare hive stand 1m away.  They don’t stop crawling, searching for food and shelter.  The brood box was also beyond repair as the larvae had bored into the woodwork and made hundreds of boat-shaped indentations as well as the thousands of eggs that would be present in the cracks.

“Luckily”, Mike, a reader of this blog did have a camera to take some photos of his wax moth larvae infested hive.  Mine looked similar.  He lit a fire below the hive below.

I lit a fire in the allotment and burnt all the frames and brood box.  I took my propane torch and scorched the roof, crown board and floor.  I’ll leave that in the field and hopefully a cold winter night will kill any remaining baddies (it needs to be below -7C for 5 hours to kill the wax moth eggs).

There were a few hundred surviving bees, so I hope they were welcomed into one of the other hives.

Here is a photo and video of a surviving larvae I found the following day:

I couldn’t find any photos online as bad as the infestation I experienced, but here are a couple of photos from Bee Aware in Australia.

How I Think It Happened

• Weakness – The hive this happened to did not have many bees.  It had failed to requeen and I added a new queen too late in the season.  A strong hive will keep the wax moth and the larvae at bay
• Easy entrance to the hive – The wax moth probably got into the roof.  I had blocked the Porter bee escapes with Blu Tack, which means the eggs could become larvae without being attacked by the bees and then the larvae could move into the brood box
• On a couple of occasions I removed bits of wax and left them on the grass

How To Reduce Likelihood of Wax Moth Infestation

1. Strong hives – colonies with many bees will manage the wax moth and keep any infestation to a minimum
2. Solid crown boards – this will close an entrance for wax moth or their lavae to readily get into the hives
3. Cleanliness – bag any wax and recycle it
4. Scorching – use a flame to scorch hive equipment that is put into storage
5. Freezing – if space and low quantity, place brood frames in freezer for 5 hours
6. B401/Certan – spray stored brood combs with B401 (also known as Certan), a safe and environmentally friendly product based on a concentrated solution of Bacillus thuringiensis, that does no harm to humans and bees

The Good News

But there was some good news.  2 out of my 3 hives are in excellent shape.  Full of bees, lots of flying bees bringing in pollen, plenty of stores for winter.

Here’s a video of the Beehaus:

Read More

• My Apiary notes
• B401/Certan (external link) – protects comb from wax moth over winter
• How to keep your bees healthy