Mites take a toll

I've had mixed beekeeping fortunes this autumn.

First the good news -- there has been some late nectar and today I took off another 60 lbs (25kg) honey. Definitely my best year for honey harvest.

But now the bad news. I don't normally treat for varroa until mid- to late-September -- and I've never had serious varroa problems. Some say we should treat in August, but I've never done this. I have three apiaries. In the village apiary, all seemed well. In the apiary on the edge of a town all seemed well -- though I didn't have to unite three colonies into two as planned since one colony (the latest swarm management split) was queenless. The colony had obviously been queenright at one time, stores were high, but numbers were low and there wasn't single sign of brood; even the workers hadn't become drone-layers. Odd, but no real problem.

However, in the third, remotest, apiary, I had a shock. A colony that I had noticed to be low in numbers earlier in the month is close to collapse. The signs of varroa infestation are unmistakable: a lot of bees looked as if their wings had been nibbled, and the brood was sparse and much was uncapped with dead or dying brood (no symptoms of foulbrood, though).

I'm not quite sure what this means. My colonies have been treated every year in the autumn and this is the first such problem. Has resistant varroa reached this apiary? Or is this colony's demise just a one-of for some reason? Or will my other colonies succumb over winter?

Meantime I've treated them all with Apiguard instead of Apistan this year. We shall see ...