Today, I'm here to talk to you about mating nucs, specifically of the 'queen castle' variety.
A queen castle is a type of nuc which contains only two or three standard frames. It's purpose is to provide the function of the mating nuc while eliminating the need for an extra type of frame. Some nuc designs use half size frames or tiny little topbars. The question is what to do with these things at the end of the year, or how to get the bees to build on them in the beginning. With standard sized frames, queen castles eliminate this difficulty.
Its prime use as a mating nuc is generally set up like this. Standard methods are used to rear queens to the ripe cell stage. Then, a frame of brood and bees and a frame of stores are placed in the queen castle with the ripe cell. Later, the nucs are checked to see how the queen is coming along and if she's laying eggs and ready to be sold. She can be removed and replaced with another cell repeatedly throughout the productive season. I've been told that the 4x2 versions offer limited space to squeeze the cell in. But according to my measurements, the three frame version offers a full 5/8" of space with normal frames. Using narrow endbar frames offers an extra 3/8" on top of that.
Another benefit is for swarm control. For instance, you go out to do a standard springtime inspection one day and you find a hive that is near to swarming with queen cells on four separate frames. This presents a fantastic opportunity to get some free bees. Take the queen and a couple frames and start a nuc with her off to the side. Then take three of the frames with adhering bees and place each of them in the queen castle in separate compartments. Add a frame of honey and pollen and an empty frame of comb or foundation. Close the thing up and wait a couple weeks and you have new nucs. You have the original queen in her nuc, one queen in the original hive, and three queens in the queen castle. You can then use these queens to requeen other hives or use the nucs to start new hives. You can also cut cells out and profit even more by using the method above.
Typical queen castles available at beekeeping supply establishments are the deep 4x2 and the medium 3x3. These two designs allow just about the same amount of comb space. Below you can see the design I came up with which in all probability is identical to the one Brushy Mountain offers. It features a standard sized box which can be used as such during the rest of the year, and three nucs divided by pieces of 1/4" luan plywood.
This is the design, but I'm going to be using it a little differently. I designed it as a medium even though I have all deeps at this point. But as you know, I'm making the switch to mediums. I'll build these as deeps and then at some point, I'll begin cutting them down to medium size. It's a simple three inch difference. The other part is that I'll make them about 1/4" taller than standard and attach the bottom board semi-permanently in the same way my 10 frame nucs are.
One thing I saw on the Bushkill Farms version was a big circular screened over vent at the upper side of the nuc to draw robbers while the actual entrance is small and located away in the bottom corner.
I'll be building these over Christmas Break, and using them next year to efficiently boost my populations.