If a hive is split and the queenless half commences building an emergency cell, can that cell be knocked down and a queen added? Or is it once they’ve started the process they won’t accept an external queen coming in?
It wasn’t clear to me from Googling as to whether this is possible or not.
I ask because I’m rubbish at finding the queen but I don’t want to do a walk-away split because of the couple of weeks it takes for them to raise one of their own.
Yes. I have done that several times. I usually wait until there is no more brood that they can make another queen from, but if they are out of eggs and young larvae, any queen will do… 
Please ask more questions if that isn’t clear. But once the old queen has been out of the hive for 6 days, they won’t be able to make a new queen of their own.
Thanks Dawn - perfectly clear!
I just asked my hubby, and he agrees. Except he reminded me that sometimes africanized colonies will not accept a mated queen. You don’t have that problem in Aussie, so you should be right with the process we discussed above. 
hi Dawn,
just a follow up to that.
i inspected one of my hives yesterday and there were no queen cells yet, very big population and going great guns tho. Swarm season is just starting here in sydney.
i have a new queen arriving on tuesday, so my question is, when i split and the old queen goes into the nuc, should i introduce the new mated queen into the original (now queenless hive) at the same time, or leave them a day to realise they’re queenless?
there is everything in the hive from eggs up, do i need to wait until there are no eggs left before introducing the new mated queen? how long can she live in the little queen cage with her attendants before she starts to deteriorate?
cheers
ron
There are many ways to do this. I normally leave the hive queenless for a couple of hours, and listen for the “queenless roar”. At that point, I introduce the queen (in a cage, or using the Snelgrove matchbox method if I am in a hurry). If I don’t hear such a change in pitch and volume of buzzing, I wait until the next day.
Not usually. With africanized bees, you often do, and even then, they may kill the new queen. They would rather suicide the colony than accept a foreign queen! 
That depends on a lot of things, but generally it is better to get her into the hive as soon as you can. The longer she goes without laying eggs, the more her ovarioles will shut down. She will start laying more slowly and may never lay as well as she would have if you had introduced her sooner.
To answer your question directly, I have kept queens alive for at least a week, if they have attendants. I usually give them a couple of drops of honey and a drop of water each day, keep them in a dark place inside the house (air-conditioned, but away from any drafts). The main problem is that the attendants start to die, and that can block the exit of the queen from the cage if you wait too long. 
brilliant, thanks Dawn.
we’ve failed in our swarm prevention for the last 2 seasons (because of mistakes we made, and now realise) and i’m determined this year to not be knocking on neighbours doors asking for my bees back.
we did one split yesterday and letting them make their own queen. that hive is descendent from our original queen almost 3 years ago and is so calm we dont even need smoke.
the second hive is a little more active, we lost the queen in that one last year and requeened from a swarm we caught in a honey customers yard, so we dont know what sort of life she’s had. that’s why we’re going to requeen that one. she should arrive tuesday or wesnesday.
fingers crossed we got it right this year.
thanks again
ron