The Beekeepers Club Inc.

Swarm Control of Honeybees (by Ian Brown)

The honeybee is a social insect, living in colonies consisting of a female egg-layer or queen, some thousands of modified females or workers which, as the name suggests, carry out all the work in the colony, and a few hundred male bees or drones which are there in case they are needed to mate with a new queen. As with all living things, honeybees need to reproduce or become extinct, but being social insects, which cannot exist individually, they have adopted a special method of reproduction, which is called swarming. In the spring, when the weather becomes warmer and nectar becomes more plentiful, the queen’s egg-laying increases and the colony may build up to 50,000, or more, bees. At this point the bees may be triggered to raise new queens in specially constructed cells. Two or three days before the first of these new queens is due to emerge, the old queen, accompanied by around half of the workers, and some of the drones, will leave the hive in search of a new home. Before leaving, the workers will fill their stomachs with honey both to act as a food reserve and to enable them to produce wax for comb building when they have found a new home. This is the swarm.

Some days before the swarm emerges, worker bees will have been scouting the neighbourhood looking for a new home, which, in nature, would be a suitably sized cavity in rocks or a hollow tree, but which now extends to many man-made objects such as compost bins, possum boxes, letter boxes, wall cavities, or any other location offering reasonable protection from weather or predators. If the scout bees have been successful, the swarm may proceed directly to the new home, but if not, the swarm will settle on some convenient place such as the branch of a tree until the scout bees have located a new home.

Having located, and occupied a new home, the bees have to build comb, so that the queen can start laying as soon as possible, remembering that it takes 21 days from when eggs are laid until a new generation of workers emerges to replace the older workers dying from natural causes. They also have to collect sufficient stores of honey during the remainder of the year to last over winter when there is no nectar coming in. For this reason, swarming normally takes place in spring and early summer. (September to December here in Victoria )

For the modern beekeeper, swarming reduces the strength, and hence the honey-gathering ability of a hive, as well as causing problems with neighbours and local authorities, and measures should be taken to prevent it if at all possible. These measures come under the two headings of Swarm Prevention and Swarm Control.

Swarm Prevention
Under normal circumstances, the queen produces chemicals, called pheromones, which are distributed throughout the colony by workers grooming the queen as she passes among them, and these pheromones discourage the bees from raising new queens and thus triggering swarming. As young queens in full lay produce maximum pheromones, it is good swarm prevention practice to have colonies headed by young queens, and to ensure that they have ample space to lay by adding an extra box of combs or foundation when necessary. Extra space should be given before the bees become too overcrowded, but conversely, do not pile empty boxes on the hive in the mistaken idea that this will stop the bees from swarming. Just ensure that the bees can comfortably occupy the boxes without being overcrowded.

Another method of swarm prevention, when the bees are becoming overcrowded, consists of adding another box of combs or foundation and re-arranging the brood frames to form a pyramid. For example, if the hive consists of one 8 frame box with 6 frames of brood, take 2 of the frames of brood and put them in the centre of a second box, pushing the 4 remaining brood frames in the first box into the centre of the box. Fill the empty spaces in both boxes with frames of comb or foundation then put the second box on top of the first. In this way, you have made a pyramid of brood frames with 4 frames of brood in the first box and 2 frames of brood above them in the second box.

Similarly, if you have a hive consisting of two 8 frame boxes, with 6 frames of brood in the first box and 5 frames of brood in the second, take a third box and re-arrange the frames of brood so that there are 4 frames of brood in the first box, 4 frames of brood in the second box and 3 frames of brood in the third box. Push the frames of brood to the centre of their respective boxes and again fill the spaces with frames of comb or foundation. In this case you will have formed a pyramid of brood with 4 frames of brood in the first box, 4 frames of brood in the second box, and 3 frames of brood in the third box. Brood arranged in this way needs more nurse bees to care for the brood, as well as giving extra space, and can lessen the chances of swarming.

Another means of preventing swarming consists of reducing the strength of the hive by taking away several brood frames to form a nucleus hive. This has the double effect of reducing the population by removing nurse bees and brood and creating more space by replacing the frames that have been removed with empty combs or foundation. (Equipment needed – 4 frame nucleus box, 4 brood frames or frames of foundation).

To make up a 4 frame nucleus hive, first find the queen in the parent hive and put her to one side, preferably in a spare nucleus hive. Next take a frame of stores (honey and pollen), 2 frames of capped brood, and a further frame consisting of eggs and young larvae, and arrange them in the nucleus hive, with the frame of stores and one of the frames of capped brood against each wall and the other frame of capped brood and the frame of eggs and young larvae in the centre. As most of the older bees will return to the parent hive, the bees from 2 or 3 further frames should be shaken into the nucleus hive so that it does not become too short of bees to care for the brood. This hive should then be placed at a little distance from the parent hive.

A loose pile of grass against the nucleus hive entrance, so that the bees have to scramble through to get out, will help to prevent too many bees from returning to the parent hive. The brood combs in the parent hive should then be pushed to the centre of the brood box with the queen’s frame in the centre and the empty spaces filled up with empty frames or frames of foundation.

N.B. Ensure that the queen is on the frame when it is replaced and, if not, check the spare nucleus hive where she was kept.

The nucleus hive, finding itself queen less, will commence to build queen cells using the young larvae. After about 5 days, check the nucleus hive and destroy the more advanced cells, leaving the less developed ones. The reason for this is to ensure that the bees, in their panic in finding themselves queen less, have not used larvae which were too old to make good queens.

After about 2 weeks an unmated queen should be present in the nucleus hive, and she may take a further 2 or 3 weeks to fly out and mate. When a laying queen is present, the nucleus hive should be checked regularly, as this new colony will eventually need to be moved to a bigger hive when it begins to get crowded.

This nucleus-making operation can be repeated on the parent hive if necessary, but care should be taken that it is not weakened so much that it is no longer capable of gathering a good crop of honey.


Swarm Control
The precautions described in Swarm Prevention above do not prevent swarming; they only reduce the likelihood, and it is necessary to inspect the hive preferably every 7 days and certainly no longer than 10 days to ensure that the bees are not preparing to swarm, in spite of all the measures taken to prevent it. This time interval ensures that if no queen cells were present at the previous inspection, then the bees cannot have reached the point of swarming before the next inspection.

The first signs that the bees are preparing to swarm will be the presence of queen cells, rather like small acorn cups, pointing downwards on the brood combs and containing eggs or young larvae. The bees have now taken the decision to swarm and prevention measures will no longer have any effect, so measures must now be taken to control the swarming impulse.

One very good way of doing this is to create an artificial swarm, which is accomplished as follows:- (Equipment needed – full-depth box, floorboard, roof, 8 frames of foundation or brood comb) First find the queen and place the comb that she is on into the centre of the empty brood box. ( N.B. If there are any queen cells on this comb, they must be destroyed ) . Fill the box with brood frames or foundation and put the roof on.

Move the original hive several metres away and place the newly formed hive, containing the queen, on the original site.

What now happens is that almost all the bees of flying age return from the original hive to the new hive and join the queen, forming what is, in effect, a swarm. The original hive, containing all of the brood and the queen cells, loses nearly all of its flying bees. In due time, a young queen emerges and destroys the remaining queen cells, since with so few flying bees, there will be little likelihood of a mating swarm. At the end of the swarming season, if an additional hive is not required, the two hives can be moved gradually closer together and united by the “newspaper” method. The queen which is not wanted can be killed, and the hive with the other queen placed on top in the uniting operation. Alternatively, the two hives can be united and the two queens left to fight it out.

Notes
1) If there are any boxes containing only honey on the original hive, these should be placed on the new hive, since temporarily, this contains all of the foraging bees with no brood to look after.

2) If the original hive is very strong, it can be split up making sure that each split contains one or more queen cells. This will reduce its chances of rapidly gaining swarming strength as well as supplying additional young queens.

3) Both hives should be inspected weekly and additional room given as required. Also ensure that the original hive does eventually contain a laying queen. This can take up to a month from when the split was made.

4) This artificial swarming operation does not guarantee that these hives will not make preparations to swarm later in the season, so the weekly inspections should be kept up.