About two weeks ago (and detailed in the last blog post) we started the process to change out some of the old comb in certain colonies. We placed a new brood chamber containing frames of foundation and a feeder with lots of syrup on top of the existing brood chamber and left the bees to it.
The weather has been unseasonably cold and windy recently, so we were unable to get into the hives and see how things were moving along. We could see the syrup was being consumed, but it was only yesterday when the weather proved warm enough to start the second phase of the Bailey comb change process by encouraging the colony to move up into the new brood box. We use the fact that the bees in a colony will always follow and surround their Queen by placing her in the top box, inserting a Queen excluder beneath her to stop her going back down to the box below.
When we do this, most of the bees will naturally follow their Queen up into the top box where they will accelerate the comb building process so that she can start laying eggs that will become the next generation of workers. Some of the younger, nurse bees stay with the sealed brood and recently laid eggs in the bottom chamber and as they hatch, the new bees move up to join the rest of the colony with their Queen.
To encourage them further, we close off the main entrance to the hive in the lower brood chamber and open up a new entrance into the top box where the new comb is being drawn and the Queen now resides. In the picture on the left you can see the bees starting to use the new entrance. The colony is unlikely to swarm as the large amount of new foundation in the upper brood chamber "tricks" the bees into thinking they have already swarmed and so they concentrate their efforts into making a new home where they are now rather than raising Queen cells and preparing to swarm.
The returning forager bees automatically home into the entrance they had left from previously and are therefore a bit confused as they attempt to get into the brood chamber. However, after a while, they realise that the entrance has moved up about 10 inches and they start to walk up the hive or fly into the new entrance. Moving the entrance like this further encourages the newly returning bees to join their Queen in the top chamber and place their foraged pollen and nectar into the new comb.
After about three weeks, all the eggs and larvae in the bottom chamber will have hatched and moved up to the top brood chamber to join their Queen. At that point we can simply remove the bottom box with the dirty old comb, leaving the bees with nice clean comb for this years new bees.
This technique is a very simple and benign process that gives the bees a nice clean home without too much disturbance and discourages them from swarming although the energy required to create the new comb will reduce any potential harvest this year. However, it is in my view a small sacrifice to greatly reduce potential disease or possible impact from any pesticides or other nasties that can build up in the comb over time.