Bees for Development
The division of a colony by reproductive swarming is the most spectacular event in the life of the honey bee. When a swarm emerges from the hive the air is filled with a throng of thousands of bees swirling around in the air- searching for their queen and a place to cluster before they start on the next stage of the adventure. The workers quickly organise this apparent chaos before getting on with finding a new nest and starting anew colony. The emergence of the swarm is only a small part of an extensive process that has been happening in the colony for many weeks.
The swarm is made up of a large quantity of workers, maybe half of the colony together with the mated queen who quit the parent colony to establish a new nest. The remainder of the workers are nurturing a new young queen who will take over and head up the old colony. The establishment of a new colony takes an enormous investment of the energy resources of the parent colony. However, honey bees are highly social insects so the great advantage of swarming is that the queen has help from many workers in order to establish the new colony as quickly as possible.
The timing of swarming will vary from season to season and from region to region. Not all colonies will swarm in any given year. Swarming, where half of the bees leave the nest and half remain should not be confused with either absconding or migration where all the bees leave abandoning the hive.
The preparations for swarming start well before any signs of swarming occur in the hive. Only strong colonies swarm as they need plenty of resources for the process in order to give both parts of the colony division the best chance of survival. For a colony to swarm they have to build queen cells. They also have to have drones that are mature enough to mate with the queen. Drones take around 6 weeks to develop and become sexually mature so drone rearing must start several weeks in advance of queen cell rearing. Colonies will only start building drones when they are well provisioned.
Crowding and poor ventilation will hinder the distribution of queen substance around the colony. An aging or poorly mated queen will produce insufficient queen substance. In either case the consequence will be that the workers will initiate queen cell building. Once queen cell building has started the chances of swarm emerging are quite high -although bees will also tear down cells and abort the swarming if conditions change for the worse.
In practical terms for the beekeeper the question is are swarms wanted - to repopulate the area and fill other hives around naturally - or can/should this process be managed to the better advantage of the beekeeper? The bees are increasing naturally; can the individual beekeeper manage this process so the swarms generated benefit that beekeeper?
The management of swarming by the beekeeper is traditionally divided into two parts; prevention and control.
Prevention is managing the colony so that the factors that predispose the colony to starting swarm preparations are minimised. This has a number of components. The first is the age of the queen. The quantity of queen substance (9ODA and 9HDAa as well as certain unidentified substances) is associated with the inhibition of queen rearing and swarming. Young, vigorous queens in their first year rarely swarm as the queen substance that they generate is sufficient to the colony together as a single unit. As the queen ages the amount of queen substance she produces diminishes so if queens are young, or kept young then the amount of swarming will be reduced. Of course, a colony that has swarmed naturally will have a new young queen so will be less likely to swarm the following year. If the colony is very large and crowded the ventilation or air flow through the colony will be impeded. This will interfere with the distribution of the queen substance through the brood nest which means it won't reach all the workers. As a consequence of this queen cells will be initiated and swarming will occur. Harvesting honey on a regular basis can help to reduce congestion in the hive which will allow the better distribution of queen substance around the colony and also gives the workers plenty of work to do in rebuilding the comb. Finally, there is a genetic component to swarming with different races and strains of bees having a greater propensity to swarm. For instance tropical honey bees are far more likely to swarm than temperate bees as they have evolved under conditions where swarming is a useful reproductive strategy. This factor combined with the general difficulty of handling some honey bee races (most notably African types of Apis mellifera) may mean that swarm management in tropical bees is not a realistic option.
The most realistic option for swarm control if queen cells are discovered in time before the prime swarm has left if to make an increase in the colony. This way the beekeeper will increase the number of colonies owned in a natural manner. To try it, look at the instructions on the dividing colonies page on this information portal.
Other beekeepers will put out bait hives in places where they know swarms will be passing to collect the swarms that leave.
List of Articles available on this topic (3):
A Guide to Swarm Control
Queen includers - the debate continues