Making sure my colonies survive the winter period is, after egg laying workers and a queen-less colony the most stressful thing I have had to deal with. A colony needs to be big enough to have a chance of surviving the winter. During the winter time the bees will congregate into a ball of bees inside the hive. The bees have to keep this ball at a relatively constant temperature of around 18-35ºC (35ºC being an indication that the colony has brood), averaging at about 24ºC, even if the temperature outside gets as low as -15 ºC outside the hive. The bees will only be able to maintain this temperature when there are enough bees. The bees vibrate their flight muscles to generate heat. During winter many, many bees will die, only hives that can sustain this die off will survive.
A beekeeper is supposed to asses his colonies strength in late summer to early fall and decide if he thinks this colony will survive the winter or not. If there is any doubt the beekeeper should combine colonies to create a stronger colony of which he can be sure it will survive winter. A colony should occupy at least 6 frames in a hive to have any chance of surviving the winter. If a colony doesn’t meet this requirement then the beekeeper should combine this colony with an other weaker colony. As I only have two colony I either combine them or I don’t.
The easy way to combine colonies is by placing a newspaper on top of an open hive box of the one colony and spraying the newspaper with sugar water. Then you place the brood box(es) of the second hive on top. The bees will have to eat through the newspaper to reach each other. The hypothesis is that by chewing through the newspaper they will all smell the same (newspaper ink) and hostility will be averted. You obviously will have to kill one of the two queens, do this a few days before uniting the hives and place the hive that still has it’s queen on top. Just parroting theory here…
As I was reasonably sure my original colony was big enough to survive winter I didn’t unite my two colonies, the colony that was the result of my artificial swarm was borderline big enough. But as I would end up with one colony either way, I chose the selfish option and I kept both colonies separate. I hope to start the next season with two colonies. I’ll be kicking myself if both colonies end up dying, that will be about 150 euro’s down the drain. I now know my original colony is still alive (because of the oxalic acid treatment I had to perform) but it wasn’t as large as I would have liked. And there are still 2 months of possible freezing weather ahead. If I were a religious man I would be praying, but me I’m just hoping for the best.
Andrew
Experience with Bees 
I think I would do the same thing you did. I hate the idea that you have to kill a queen to combine. I don’t treat though. When you poison mites, you are killing not only the ‘bad’ mites, but you’re killing the good mites too. According to Michael Bush, author of “The Practical Beekeeper,” there are 32 kinds of mites, which contribute to the ecosystem of the hive. I think we should let the bees adapt to the mites. If we keep trying to poison the mites, they will develop a resistance to the poison and become stronger, to the detriment of the bees.
Resistance to either of the acids used in beekeeping is very unlikely, they are acids that occur in nature to a good amount. The resistance would have to be to general it would most likely make the life of the mites impossible. There are already many organizations (mostly universities) searching for bee variants that are more resistant to the Varroa. I’ll wait till they have found before I stop treating my bees for Varroa. I’m quite sure I would have lost one of my colonies if I hadn’t.
I’m not familiar with the book you mentioned, I’ll keep it in mind, perhaps one to read.
But won’t some of the mites live through the application? According to this article, they will. http://www.telegraph.co.uk/earth/wildlife/10285919/Honey-bee-treatment-applied-in-wrong-way.html The comment is also apt.
I’ve got a Warre hive that shows many varroa mites on the bottom board. They are using their own natural built comb. I’m not sure if that has anything to do with it (small cell), but they are flying well and close ups don’t show any mites on the foragers. In my opinion, we will never totally rid the bees of mites, but hopefully can get them (the bees) adapted to living with them.
Footnote2…I finally got your site to open fully (correctly) by clicking on the three lines in the orange margin on the left.
Some mites are sure to live through any treatment, either on the bees or in the hive. But the oxalic acid treatment is a way to drastically reduce the number of mites.
And no we will never be rid of the mites completely, what we should want is a bee that is able to handle the pressure that the mites put on the hive, bees that are more fastidious when it comes to cleaner each other.
The three lines on the side are just to show or hide a kind of index of the site, a WordPress “feature”.
A footnote here…when I opened your blog to a ‘full open,’ I couldn’t read it. The copy was placed all the way over to the right in a narrow column. Opening to the ‘partial open’ let me read it without ‘issues.’
Weird, perhaps a problem with the theme, could you send me a screencrab (andrew@millar-knorr.nl)?
It works okay on the iPod. I’ll send you a screen shot when I fire up the laptop.