Interim Nucleus
Lexikon
An interim nucleus is a method for calming a colony that has already fallen into swarming mood at the same site, without sacrificing its foraging performance.
An interim nucleus is a method for calming a colony that has already fallen into swarming mood at the same site, without sacrificing its foraging performance. For this, in a colony with a divided brood chamber, the arrangement is changed: a further flat floor with its own entrance and an additional queen excluder is inserted between the two brood boxes. The flight-inclined bees sitting in the lower part then fly in and out through the lower entrance, while the queen remains in the upper part.
The Kirchhain bee institute describes a variant with three interventions at weekly intervals for this: at the first intervention, the brood chamber and honey super are swapped and an open brood comb is hung into the new honey super, and existing queen cells are broken. A week later, the brood chamber is checked again for queen cells and the open brood comb in the honey super is exchanged for a fresh one. After a further week, the brood chamber and honey super are swapped back. Other guides instead form an independent nucleus above a divider board with the queen and part of the brood, and check at the next inspection whether the swarming urge has subsided.
The reason this works is similar across all variants: through the separation, the brood-inclined part of the colony suddenly lacks flying bees, so the colony strength needed to swarm is no longer reached, while overall honey intake continues, because the flying bees keep foraging. An open brood comb in the separated part also prevents the bees there from feeling completely queenless.
In everyday practice, the interim nucleus is especially popular with colonies that keep starting queen cells despite expansion and removal of brood. A common mistake is delaying the check for too long, because then the bees separated from the queen lose contact with her for too long and false queens can develop.