After buying a bee colony which you will probably do in June or July, the important action you most likely will have to perform first is taking swarm preventative measures.
When a colony exceeds a certain number of bees it will want to swarm. If a colony becomes to big it will most likely overheat the hive, which will kill the colony. A colony will swarm irrespective of the amount of room it has. The colony will need a new queen to swarm, worker bees will initiate the swarming by building queen cells. The old queen will take about half the colony and leave the hive to find a suitable place for a new colony.
To prevent loosing half your colony you will have to anticipate the formation of a swarm by being watchful and notice when the colony begins to make queen cells. When you notice queen cells you can immediately make an artificial swarm. If you’re not quite ready removing the queen cells will give you some time. When you have decided to make an artificial swarm there are a number of ways you can proceed, some methods require more work than others, I’ll cover a few here.
You will need to make a number of decisions when making an artificial swarm. You first decision concerns the old queen, do you keep her with the old colony or will she accompany the artificial swarm. When you put the old queen with the new colony the old colony will need freshly lain eggs (up to 3 days old) with which they can make a new queen. The same thing goes if you keep the old queen with the old colony, the new colony will need freshly lain eggs to create a new queen.
Then you have to choose where you want to place the new colony. If you want to put the new colony close to the old colony all the gathering bees will fly back to the old hive. You have to take that into account when adding bees to the artificial swarm as it will lose many bees to the old hive. The new colony also will need food to last until the younger bees start foraging. Also bees that are to young to forage don’t yet protect the hive, you will have to keep the hive entrance very small to ward of stealing, which bees will do. In time the young bees will be old enough that they will start to protect the entrance and go forage.
When you don’t place the new colony close to the old colony you have to make sure the distance to the old colony is at least 6 kilometers (3.7 miles), that is about as far as honey bees fly when foraging. Placing the hive inside that range will cause many bees to return to the old hive.
Getting a new queen in the old or new colony also takes some doing. When the bees notice that they are queen-less, which happens quite soon after they become queen-less, they will make what is apparently called a emergency supersedure (wiki) by converting a normal worker cell with a young egg into a queen cell and feeding the developing larva royal jelly. As beekeeper you should either remove all but two queen cells or be very attentive or risk an after swarm. The development of a queen takes about 16 days and the egg that occupied the cell that was made into a queen cell could have been as old as 3 days. After 13 days a beekeeper should start listening at the hive, if a queen has hatched you will be able to hear make a noise by vibrating against the comb. The queens still in their cells will do the same in their cells which will sound slightly different. When you notice this you will need to remove the other queen cells to prevent getting an aforementioned after swarm.
The new queen will most likely kill the virgin queens in their queen cells for you but just to be on the safe side removing them is best. Normally virgin queens will continue leaving the colony if they decide the colony is still to large. Having one artificial swarm per year is most often enough. Needing a second one is very rare.
An other thing you can do, instead of letting the colonies make their own queen, is introduce a new fertilized queen from a pure breeding line. You can do this to get a colony with more desirable traits, like docility, increased honey production and low swarm tendency. However doing this is something for the more experienced beekeeper, because it can go wrong and the bees may not accept the new queen and kill her.
After a number of generations of queens from a pure line queen the colony will lose the traits associated with the original subspecies of the first queen. They will most likely become more aggressive and the tendency to swarm will increase. Swarm management is one of the most important tasks in beekeeping, only varroa treatments are about as important to the survival of you colony.