Now that I covered checkerboarding as a swarm control strategy, I want to at least mention a practice called “opening the brood nest.” This is a technique where empty frames are placed between frames of brood. Many people confuse checkerboarding with opening the brood nest. The important distinction is that checkerboarding is done above the brood nest and does not disturb it. On the other hand, “opening the brood nest”—sometimes called “spreading the brood”—disrupts the integrity of the nest.
Here are the basic steps:
- At the first sign of new white wax on or near the top bars you can begin.
- Remove one of the frames near the middle of the brood nest. It should fill with festooning bees within about five minutes. If it doesn’t, it’s too soon to open the nest because there aren’t enough bees to repair it.
- Assuming the empty space fills with festooning bees, return the frame to the same position.
- Take an outside frame (one with no brood) out of the box, and push the remaining frames to the side, leaving the empty slot near the middle of the brood nest.
- Put a new foundationless frame in the empty slot. The bees will now direct their energy to building new comb and filling in the brood nest rather than swarming.
- Depending on the strength of the hive, one or maybe two foundationless frames can be added to the brood box. Each empty frame must have filled brood comb on either side of it.
- If there is already brood on all the frames, the frames of brood you remove may be centered in a second brood box directly above the first.
- To be successful, you may have to re-open the nest and add frames every week or so throughout swarm season. Far from being a one-time manipulation, it requires constant monitoring.
Timing is everything with this technique. It must be done before the swarm impulse begins or it is completely ineffective. On the other hand, if you do it too soon you can chill the brood. When the nest is split up—and it will be for a period of time—it takes more bees to keep the brood warm. An unexpected cold night soon after spreading the nest could devastate the colony.
Just for the record, I do not like opening the brood nest for swarm control. I believe strongly that the integrity of the nest should be maintained. As I stated earlier, swarm control measures work by weakening the hive in some way. By changing the architecture of the nest, you are interfering with the bees’ judgment about what is best for the colony—and you are doing it repeatedly. So if you decide to try it, do so with caution: read colony strength carefully and pay close attention to the weather.