Two Queen Hives
I will preface this with the fact that I've done this and think it is usually easier to just run two one queen hives. The biggest problem for me is that you have a super hive with supers stacked up to the clouds and bees everywhere and to do anything with the queens requires moving and disturbing every box. All those bees can be very intimidating, especially to a beginner. I think to be practical it requires a system that does not require moving any boxes to get to either queen.
That said, the concept is that two queens will lay twice as many eggs and build up twice as fast in the spring. More workers, more honey. In experience, since Dzierzon says a queen can lay 3,000 eggs a day, I think it's the added QMP (Queen Mandibular Pheromone) that causes it to be more productive. Both because I think one queen is capable enough and that the timing never seems to work out so that they could raise that much more brood that much earlier.
There are a few different tactics you can use to accomplish this. One would be the low equipment, low labor, less reliable method of just raising queen cells and putting them in the top box to emerge. This often, but not always results in a two queen hive with minimal effort. You can increase the odds by putting a queen excluder somewhere in the middle of the boxes. Of course both have to have a way for the drones and virgin queen to get out. This often works but in the worst case they get requeened and best case they end up with two laying queens. I've done this accidently when queen rearing on several occasions. For details on how to mate a queen in the top of a hive see Doolittle's information on it.
A type of Demaree also works fairly well to end up with one. Just build a double screen board (or two single screen boards) and put one box of brood over the screen board. The bees rear a new queen in the queenless part (whichever that may be) and when you approach the main flow, you can do a newspaper combine with or without a queen excluder.
If you want to be more reliable, here is my design for a manageable two queen hive. I would set up a horizontal hive that is three boxes long. (48 ¾") with the entrances on the long side. Make it so you can open or close an entrance on any third of the box on any of the two long sides.
The box needs two grooves into which a piece of a queen excluders fits to divide it into thirds. This allows a queen on each end and supers in the middle.
You can use any of several methods to get the hive to accept two queens, but they are separated enough to not fight and you have two brood nests and one stack of supers in the middle. You can purchase queens, leave the hive queenless for 24 hours and split the brood nest into the two brood boxes with a caged queen in each and try for simultaneous introduction.
If you raise your own queens, you could put a virgin on each end and hope they fly back to the right hive when they are done mating.
You can split the brood into the two brood boxes and divide the hive with a partition, instead of an excluder to make one side queenless and then remove the partition when the queen cells are doing well on the queenless side. It is an art and you need to practice and accept that it may not work the way you think the first few times.
The best time to get two queens laying is early in the spring. The earlier the better. During the honey flow you might be better off to split the hive and put all of the open brood in one of them and most of the bees in the other to up the production in that hive because lots of brood rearing DURING a honey flow does not help production.
Snelgrove had a plan for using one hive to stock the other that was quite ingenious by manipulating entrances above and below a double screen board and perhaps some way could be figured out to do that in a more horizontal configuration.
Copyright 2006 by Michael BushThis page in Polish