The 'classic' way of dealing with a colony that is about to swarm.
With an artificial swarm the queen and the flying bees and any bees in the honey supers remain on the original site and the brood with queencells and younger bees is moved a few feet away. Optionally, a week later, the brood and queencells is moved to the other side of the original site so that any more flying bees return to the queen to strengthen the honey gathering ability of the original stock. It is quite possible that the original colony will produce good levels of honey while the queenless colony will produce a new queen and build up rapidly and may even produce honey too.
When you see open queencells - that is with a larva and royal jelly inside - you know that the colony is preparing to swarm*. Without intervention you can expect them to go when the queencell is sealed if the weather is OK. You can buy yourself a few days if you need to by removing the queencells -provided the queen is present and there are eggs in the colony. I cannot stress this too strongly ALWAYS check that the queen is present or there are eggs in the hive before you remove queencells. However, if queencells are built again, then you need to do an artificial swarm.
What to do
With the colony open; remove it 3 feet to one side and place the brood chamber on a hive floor. Place a new brood chamber on the floor on the original site and place the queen on her frame of brood in it. ensure that there are no queencells at all. Make up the space with frames of drawn comb or foundation or a mixture of both. Drawn comb is better if available. For safety sake you may wish to put a queen excluder under the brood chamber for a week - just in case she wants to go. Place any supers on top of the queen excluder and put on the crownboard and roof. You now have a colony with few nurse bees and little brood. However, it has a queen and all the flying bees will return to the hive so there is plenty of honey-gathering capability.
For the remaining colony, select one good open queencell - with a larva in plenty of royal jelly - and destroy the rest. If you have sealed queencells as well as open ones, then they - the sealed ones - should be removed in preference to the open one. The reason for this is that you know the open queencell is viable as you've seen the larva and you are better able to predict when the queen will come out. Mark the top of the frame with a drawing pin or some other way so you know where the queencell is positioned. Push the frames together and place a spare frame of comb or foundation in the space at the side of the brood chamber and put on the crown board and roof.
In 5 - 7 days check both hives. The queenright colony may have produced more queencells. If the queen is present, they can be cut out. The queenless colony will probably have more queencells by now. Identify the queencell you wanted to keep and look after it. Ensure there are no other queencells on this frame. For the other frames you also need to check for queencells; Shake the frames if there is any doubt about the presence of queencells as they tend to be hidden out of view. In addition there may be emergency queencells built from worker larvae on the face of the frames, and these must be removed. You can shake frames of worker and drone eggs however you must NOT shake the frame your wanted queencell is on. If you wish you can carefully move the queenless hive to the other side of the queenright one. Any flying bees will strengthen the honey-gathering colony as they will return from foraging and not being able to find their hive, locate the nearest one and go into that.
Your queenless hive has one queencell inside and plenty of young bees. They may need to be fed - remember you have removed their stores and the flying bees which gather the food, are not present.
The queen will emerge 8 days after the queencell was sealed. It will be anything from 10 - 40 days before she mates and starts laying. From experience in my apiary the average is around 16 - 18 days. For this reason the colony needs to be left as the queen should 'ideally' not be disturbed especially when she is likely to be out on mating flights. See 'When will my queen start to lay.'
Artificial Swarm in the foreground. The queen is is the hive with the supers in the left of the picture and the colony can continue to gather honey. The swarming urge should go as there is hardly any brood and the queen will start to lay up brood combs. The brood box on the right has brood and the queencells. Any older flyers will return to the parent colony. Note there is a feeder on this colony as it will not be able to gather any nectar until the bees mature and it regains flying bees again. Queencells should be reduced to one. See text.
Once the new queen starts to lay well - say after a couple of weeks of laying and you can see a good brood pattern developing, you can decide what to do with your new colony.
As you have removed most of the young bees from the queen on the old site the colony has few bees to rear brood and draw wax which is why it is beneficial to have at least some drawn comb in the hive for the queen to lay eggs in. However it will take a little while for the colony to really get going with brood-rearing and during this time there are plenty of older flying bees that can bring in the honey. With luck and a good flow on you have 2 or 3 weeks for the bees to fill a super or two of honey before these older bees die off and before the youngsters emerge.
How many queencells should be left?
I only leave one queencell to mature into a virgin queen; with two there is a good chance that a cast swarm will issue with the first queen to emerge, which will weaken the colony. As the whole aim of an artificial swarm is to stop swarming, you don't want to chance it.
The queenless colony will have quite a few bees in it and it can support a frame or two of brood, some shaken bees and a queencell being removed to form a nuc to give a better chance of queen mating; thus we have a nuc with queencell as well as a decent sized colony with queencell too. There are precautions that would need to be taken with this approach. Specifically close up the nuc for a couple of days and keep it in the dark and don't feed either for a few days until bees have orientated about their new home.
Can I inspect a colony with a virgin queen?
Many books say no but I have seen no evidence of these young queens being harmed as a result of inspection. But there is a proviso. Don't inspect the colony when there is a chance that the queen will be out on mating flights as she might get confused by having the hive open and you hanging around when she returns. In the height of summer she can be flying from 10 am to 6 pm. So you can check in the evening after tea but only if you need to. Inspections should not be done for fun but for a reason!
*Swarm cells are usually 5 or more in number and around the edge of the brood nest or on the bottom bars. Supercedure cells are typically 1 - 3 in number and often on the face of the comb. In supercedure, the colony will replace the queen without swarming (usually). It can be difficult to know exactly what the bees are up to and will be the subject of another page later.
Other methods of swarm control include the 'Nucleus Method' taking the queen away and forming a nucleus colony and a 'Demaree.'
More info and pictures will follow.