One or two queencells

[Spike]

I borrowed a couple of books from the library and one said leave one queencell and the other said leave two.
What should I do?

[NigelP]

Whatever you feel more comfortable with.
I leave 2, Adam leaves 1.
I believe in the extra insurance of 2 in case one is dud. And to date have never had a hive swarm when leaving 2 cells.
In practise though if you have seen a nice juicy larva in the queen cell before it has been sealed I would say you are safe to stick with 1.
The problem though is all he queen cells you have missed hidden away on other frames, when selecting the 2 (or 1) to leave
Its why I use Snelgrove as my go to method of swarm control as the bees tear ALL the queen cells down for you.....at least they usually do. I had a puzzler his week where they hadn't torn them down. Then I noticed no eggs or young larvae and no queen in either box.

[AdamD]

I do leave one and have definitely seen swarms leave with the first virgin out, if I have left a queencell by mistake - as you say Nigel, it's often an emergency one that was missed or arrived very late to the party. I would not deliberately leave two; and those nice well-supplied larvae in a queencup are almost certainly going to produce a good queen.
Small colonies are less likely to swarm if there are two queencells compared to a full-sized one.

I had a go at queen-raising using the miller method a couple of weeks ago which is a method that I don't usually use. It worked well and I obtained some nice queencells, I used some and then put the frame into a small nuc with the idea that the 8 or 9 virgins remaining would sort themselves out once they emerged. I believed the nuc to be queenless. However it wasn't and the queen that I had not been able to find, speared they virgins in their cells and when I inspected, all were in the process of being broken down from the back - and then I saw the queen - and eggs; She had just started laying so she had definitely been there all along.