Twin Towers Queen-Rearing (John Harding method)
Introduction
Despite looking decidedly odd, raising queens using this contraption is remarkably simple. It's probably best to start in early May so that you can utilise it throughout the summer.
The equipment
The setup consists of two queenright colonies made up using 6 frame boxes, one on each side of a queenless nuc, with an added feeder, in the middle. The connections are made using 150mm lengths of 50mm diameter plastic tubing (here it's transparent which allows you to see what's happening). The hive ends of the tubes are fitted with pieces cut from a plastic excluder, to prevent the queens from moving into the central nuc. The queenright colonies will, of course, grow rapidly in the spring and early summer, so it will be necessary to provide room in the form of expansion boxes, turning them into vertical hives, from which its nickname of Twin Towers came.
Each of the three boxes has its own entrance - these are not shown here, they are on the opposite side. It's important that the entrance to the central nuc is turned to the queen excluder setting in order to prevent a passing virgin queen from entering.
Despite looking decidedly odd, raising queens using this contraption is remarkably simple. It's probably best to start in early May so that you can utilise it throughout the summer.
The equipment
The setup consists of two queenright colonies made up using 6 frame boxes, one on each side of a queenless nuc, with an added feeder, in the middle. The connections are made using 150mm lengths of 50mm diameter plastic tubing (here it's transparent which allows you to see what's happening). The hive ends of the tubes are fitted with pieces cut from a plastic excluder, to prevent the queens from moving into the central nuc. The queenright colonies will, of course, grow rapidly in the spring and early summer, so it will be necessary to provide room in the form of expansion boxes, turning them into vertical hives, from which its nickname of Twin Towers came.
Each of the three boxes has its own entrance - these are not shown here, they are on the opposite side. It's important that the entrance to the central nuc is turned to the queen excluder setting in order to prevent a passing virgin queen from entering.
Raising queens
Each week the central nuc is given a frame of open brood, a frame of pollen, a frame of food, a frame of grafted larvae, and a frame of foundation to discourage them from drawing comb on the frame of grafts. The central nuc is also fed 1:1 sugar syrup. Nurse bees are attracted from the colonies on the sides to the frame of open brood. While it may seem counterintuitive that the bees don't fight, the separation from the colonies to the sides means that there is not enough queen pheromone to make them defensive. This also has the effect of making the bees happy to build queen cells from the grafts.
The following week, the sealed cells are moved to a finisher colony, the sealed brood is put into one of the colonies on the sides, and the process starts again.
Initially, the bees may not draw many cells, but they seem to learn that this is what they're supposed to do, with the result that, as the weeks roll on, the success rate continues to improve.
Things to watch out for
The two hives on the sides should be treated as ordinary hives, so they need to be inspected regularly to manage any swarming impulse. They can get quite congested so this is an important part of the process. Similarly, the open brood frame provided to the middle nuc should be checked for queen cells.
Since there are queen excluders on the ends of the tubes, and the middle nuc's entrance is closed to the queen excluder setting, there is no way for the bees to remove dead bees. This is quite apparent in the photo of the tube above. A possible fix for this is to make it possible to remove the tube and empty it - this would have no real impact on the system.
Variations
While the above references the use of grafting larvae, this method could be used with any queen-rearing technique, e.g. notching frames of brood.
In the setup above, the queens can freely move around the stack of nucs. It may be preferable to restrict the queen to one particular box at a time, and this can be achieved by the use of a nuc queen excluder.
Each week the central nuc is given a frame of open brood, a frame of pollen, a frame of food, a frame of grafted larvae, and a frame of foundation to discourage them from drawing comb on the frame of grafts. The central nuc is also fed 1:1 sugar syrup. Nurse bees are attracted from the colonies on the sides to the frame of open brood. While it may seem counterintuitive that the bees don't fight, the separation from the colonies to the sides means that there is not enough queen pheromone to make them defensive. This also has the effect of making the bees happy to build queen cells from the grafts.
The following week, the sealed cells are moved to a finisher colony, the sealed brood is put into one of the colonies on the sides, and the process starts again.
Initially, the bees may not draw many cells, but they seem to learn that this is what they're supposed to do, with the result that, as the weeks roll on, the success rate continues to improve.
Things to watch out for
The two hives on the sides should be treated as ordinary hives, so they need to be inspected regularly to manage any swarming impulse. They can get quite congested so this is an important part of the process. Similarly, the open brood frame provided to the middle nuc should be checked for queen cells.
Since there are queen excluders on the ends of the tubes, and the middle nuc's entrance is closed to the queen excluder setting, there is no way for the bees to remove dead bees. This is quite apparent in the photo of the tube above. A possible fix for this is to make it possible to remove the tube and empty it - this would have no real impact on the system.
Variations
While the above references the use of grafting larvae, this method could be used with any queen-rearing technique, e.g. notching frames of brood.
In the setup above, the queens can freely move around the stack of nucs. It may be preferable to restrict the queen to one particular box at a time, and this can be achieved by the use of a nuc queen excluder.