The loss of our colony

At the end of Summer 2012, we were a bit worried about our varroa levels. We applied Apiguard (thymol) after removing the honey supers, but even after finishing the treatment, we saw phoretic mites (mites on the back of adult bees) and some deformed wing virus (a virus transmitted by varroa).

After talking to some of the experienced beekeepers at the local association, we discovered that we probably had not applied the Apiguard close enough to the brood nest, and we also found that we hadn’t sealed up the hive sufficiently at the bottom, so perhaps the treatment hadn’t been as effective as it should have been.

What to do? After some discussion and mulling it over, we decided to repeat the treatment, even though it was getting late in the season. We figured we didn’t have much to lose. The varroa load seamed to be so heavy that we risked losing the bees over the winter anyway. Late summer is such a criticial time, as it is when the bees are being born that will need to overwinter. These bees will live for about 6 months. Any shortening of their lives as a result of diseases and viruses transmitted by the varroa mites can mean that the colony does not survive the winter because not enough of the winter bees live for long enough to be replaced by their spring sisters.

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The second time we made sure that the hive bottom was well sealed up so that the thymol fumes would stay in the hive.

Sadly, as is evident from the title of the post, our colony didn’t make it through the winter. They were still alive when we treated with oxalic acid in December, but already by that point very small in number.

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This is the last photo of queen Gilla, and even in this photo the mite load is evident – the bee at the bottom left of the photo has a mite on her back.

By late January/early February, it seemed evident that the colony was not faring well. There was little, if any any, sign of life, no flying, and very little debris on the monitoring board when we put it in.
IMG_4558When we opened the colony in March, we found the poor, dead colony and queen. They had formed two separate clusters, heads into cells, close together and despite having fondant and other stores, they seemed to have starved. This is known as isolation starvation, where the cluster gets stranded from the stores, and it is too cold for the cluster to break for them to move to the rest of the stores.

There were also signs of dystentry on the frames, as can be seen on the photo above.

It’s hard to be conclusive as to the reason that they died. I suspect it was the combination of a number of factors. High varroa load, weakened colony in terms of numbers and probably health, and cold weather stranding the small (and probably unviable) cluster from its stores.

The BBKA winter survival survey indicated losses of more than 30% in England this winter, so we were not alone. But with only one colony, it’s all or nothing. A sad way to end the year, but we’ve learnt a lot, and hopefully we can put these skills and knowledge to better use in the upcoming season.