Copper Bee Apiary

A garden apiary in Whittlesford, Cambridge, UK - honey bees and their beekeeper Hilary van der Hoff.

EFB Picture Diary Part VI

Out, foul scourge

Oh, my poor bees. My poor, beautiful bees.

The EFB disease came back.

With horror, I saw it in the brood combs when I was checking my colonies before a planned uniting. They say to always check colonies for disease before uniting them, since you don’t want to risk uniting a healthy colony with a diseased one. Well, they’re right. Although in my case, it would’ve been the uniting of a diseased colony with another diseased one.

The brood aren’t alright

So I called out the Bee Inspector. He found five colonies with suspicious brood, and one healthy colony. Tests on the five confirmed EFB in the colonies of Queen Victoria, Queen Wyvern, Queen Yin and Queen Anne II. In Queen Victoria’s case, the infection was at the lowest possible detectable level - just a single infected larva was seen in the whole colony. But a positive test result still means a death sentence. Queen Xanthe’s colony tested negative for the disease. However, they are a small colony and I doubt they have enough bees to get through the winter alone. I had been going to unite them with another colony, but in the circumstances I will now keep them separate rather than risk infecting the single healthy-looking colony that I have.

The Inspector also found other types of brood fatalities in several colonies, including sacbrood (virus), chalkbrood (fungus), and varroa (mite). Those are relatively common, so seeing them was nothing out of the ordinary, but the Inspector noted that bees may succumb to disease more easily when battling multiple pathogens at the same time. Here’s a photo of some varroa-killed brood that the Inspector removed from their cells - you can still see the dark, oval mite stuck to one of them. Their white bodies are broken because the worker bees had already tried to lift them from the cells and they get broken in the process.

Death by varroa

The one colony for which there was no suspicion of EFB was Queen Uma’s - the new bees that I brought home from a hedge in May.

Were the EFB bacteria lurking in my other colonies all along, even when they appeared free of the disease when inspected earlier this year? Or did we eradicate the disease, only for the bees to be subsequently re-infected from a surviving reservoir of bacteria? And if so, where was - or where is - that reservoir? Don’t know.

As well as having the sorrow of knowing that my dear bees had to die, I was anxious about having to kill them with petrol again. Last time, it didn’t kill them all and many were still alive and suffering the next day. This time, I used a LOT of petrol, much more than the prescribed pint per colony. I poured in jar after jar and listened until their buzzing had completely subsided.

Hives taped for petrolling

Dead bees

That was more effective - almost all the bees appeared to be dead when we came to burn the combs in the morning. There were some still crawling, but the Inspector was not surprised - he said there were usually some survivors. We got the fire going as strongly as possible in the rain and burned all the combs and bees.

In a now familiar routine, the Inspector scraped clean the outer wooden and metal parts of the hives and sterilised them with a blowtorch, and I cleaned and sterilised the other washable parts, while the combs of bees burned and smouldered.

Torched kit

I’m going to clean those hives a second time before storing them, and the same goes for all my other beekeeping kit, of which there is quite a lot. I want to make doubly sure none of it is harbouring EFB bacteria.

I hope the blowtorch has already done a good job, because I saw a worker bee harvesting propolis from one of the stacked up brood boxes.

I’m glad to have Queen Uma. Her bees have been a little hot tempered compared with some of my other colonies, and I’ve felt their stings a couple of times, but it would be a much sadder and quieter apiary without them.

Writings, images and sound recordings are by the beekeeper unless otherwise indicated. All rights reserved.

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