Swarm prevention

When a honey bee colony reaches a certain level of development, part of the population may leave the hive to form a new colony. This division is called swarming.

This is the natural reproduction of the colony viewed as a superorganism. It enables reproduction and thus the survival of the species, and has done so for millions of years. However, beekeepers aim for colonies that develop well and become strong without swarming. What methods can be used to prevent swarming?

1. The onset of swarming fever

Brood development reaches its peak in June

When a colony has grown a lot and the bees have almost no space left, the queen’s movements are also restricted, especially when there is more and more capped brood and she can hardly find any empty cells in which to lay her eggs. The Anhardt gland then secretes a marking pheromone (footprint). This marks the beginning of swarming fever.

2. Factors that promote swarming

breed and strain of the colony: some breeds are far more prone to swarm than others
genetic predisposition of the queen
time of year : especially in spring before the main nectar flow
lack of space (congestion of the brood chamber): many frames of capped brood, no opportunity for the queen to lay, with a very high concentration of bees
a hive that has become too small: this generally occurs after the arrival of large amounts of pollen, which rapidly increases the colony population. The consequence: a dilution of the concentration of the queen’s pheromones because the colony is overcrowded
lack of space to store honey during the nectar flow
lack of space for comb building
unfavourable weather conditions: prolonged bad weather after a good flower nectar flow, changeable weather
too much liquid feeding in late spring
the age of the queen (2 to 3 % swarming for a queen from the current year, but n+1 ➜ 20 % (for a 2-year-old queen) and n+2 ➜ 50 % (for a 3-year-old queen). Destroying queen cells is not enough to prevent swarming)
excessive sunshine on the hive entrances and excessively high temperature in the hive (insufficient ventilation)

3. How can swarming be managed ?

provide space in time (new frames to draw out, add supers, remove brood frames with bees, etc.)
let many frames of foundation be drawn
regularly cut out drone frames
introduce young, high-quality queens
more swarm-prone genetic predisposition: choose a quality queen. “Any-source” queens swarm much more than queens produced by professionals.
shade on the hive entrance in the afternoon from deciduous trees (plant deciduous trees to provide shade…)
clip one wing of the queen (this is not a method for preventing swarming, but a method for recovering swarms)
regularly destroy queen cells (at least once a week) is sometimes recommended, but in fact tends to accelerate swarming
take a package of bees
remove frames with queen cells and make nuclei ; the queen can be replaced later if desired
remove the queen : take a frame with the queen, move it to a nucleus box in an apiary at a distant location ; destroy the queen cells immediately and then again one week later ; return the queen to the hive, as if introducing a new one
replace the queen : if the queen is replaced and the queen cells are removed, the fever will probably subside
splitting or artificial swarming (see chapter 3.1)
reversing the brood boxes in spring (see chapter 3.2)
apply the Demaree method (or “checkerboarding”). Its main objective is to separate uncapped brood, including eggs, from the queen (see chapter 3.3)
apply the Virdis method: transfer capped brood into a second brood box above the first (see chapter 3.4)
cage the queen (a method currently being tested by Serge Imboden and Claude Pfefferlé, Société d'apiculture de Sion: www.apision.ch) : See chapter 3.5 and the article: ► Extinguishing swarming fever

3.1 Method 1: artificial swarm

(see article : ► Creating young colonies)

Work procedure:

catch the queen from the mother colony and place her in a queen cage
place the cage with the mother-colony queen, or a new breeder queen, in a swarm box (or in a nucleus box with frames of foundation)
remove 1 to 2 kg of bees from the colony (or from several colonies) but without the queen, and brush them into the swarm box
immediately give some liquid feed to the artificial swarm
place the swarm in a cool, dark cellar until a homogeneous swarm cluster has formed around the queen cage (one to two nights)
set it up at a young-colony site about 3 km away with frames of foundation and release the queen (if the artificial swarm is to be housed on the same site as before, it must be kept in the cellar for at least 4 nights and fed)
first check after 7 days (see whether the queen is accepted; otherwise introduce a new queen; number of bees, feed, etc...)
treat the nucleus with oxalic acid (by spraying, trickling, or evaporation)
check the donor colony (queen cells, presence of the queen, presence of eggs)

3.2 Method 2 : reversing the brood boxes

(see also the article: ► Understanding swarming)

An easy method is reversing the brood boxes in spring. It mainly applies to colonies wintered on two brood boxes, although it can also be applied—after adding a second brood box—to colonies wintered on one brood box, outdoors or in a cellar. The principle is as follows :

Bees in colonies wintered outdoors on two brood boxes will consume their syrup all winter by gradually moving up into the upper box. Normally, at the end of winter, the cluster is in the upper box, with the lower one empty. The queen therefore starts laying in the upper box. By reversing the boxes at that time, the empty space is placed above the cluster and brood, which is more natural for the colony. The queen can then move up to lay in this empty box. The boxes can be reversed again a few weeks later, when the brood in the lower box is emerging, in order to place this newly freed space at the top of the colony. In this way, the queen is given sufficient laying space, and the number of foragers going out when the nectar flow arrives is maximised.

3.3 Method 3 : the Demaree method

A good way to prevent swarming is to use the Demaree procedure. This procedure was devised by George Demaree and first presented in the American Bee Journal in 1884. Its main objective is to separate uncapped brood, including eggs, from the queen. The brood is placed above a queen excluder while the queen is kept below. This procedure reduces overcrowding in the hive and its urge to swarm. It thus makes it possible to keep the entire population and maximise honey production.

This is essentially an artificial swarm without physically splitting the colony. All brood, except a good comb of larvae and capped cells, is transferred into a brood box that is installed above the honey supers (for Dadant hives: 2 supers stacked). In the lower brood box, a frame of stores, the brood comb (with the queen, of course), and 8 empty drawn frames are left. The queen excluder is then placed between the lower brood box and the honey supers.

The queen is thus left with 8 combs in which to lay. Most of the bees remain above with the brood, but will move back down as it emerges. They will eventually fill the upper brood box with honey.
Because the bees that remain with the brood in the upper box no longer “sense” the queen, who is below, they will think they are queenless and will attempt to raise a new queen from eggs present in the combs. It is therefore important to return and destroy ALL queen cells on the combs in the upper box one week to 10 days after the operation.
This procedure makes the bees “believe” that swarming has taken place, and moreover this sudden addition of laying space for the queen will noticeably increase the colony population in the following weeks.

This plan is initially intended to reduce or even suppress swarming by separating the queen from almost all of her brood, forcing nurse bees to leave her to care for the nursery separated by an excluder and placed at the top. The conditions for swarming are therefore no longer met at that time ; it is a form of swarming within the hive. It is applied to a strong colony, but if the aim is to obtain queen cells, a colony of moderate strength can be used. The advantage of this plan, which takes little time to apply, is that the (always tedious) search for the queen is avoided, the bees keep the same odour, and the harvest is substantial if weather and floral conditions are favourable. There is no splitting, no grafting, no nucleus box, no moving away and no cellar confinement. The colony retains its entire population and its dynamics.

3.4 Method 4 : the VIRDIS method

When the colony has developed well and occupies all frames in the brood box with an extensive brood nest, it is time to place the queen excluder and add 2 supers.
From the brood box, 2 to 3 frames of capped brood (with no possibility of queen rearing) are removed and replaced by 2–3 drawn frames or frames with foundation. The queen must imperatively remain in the brood box below the excluder!

The frames of capped brood are placed in the centre of the two supers. At the sides, frames (super or brood frames) are placed, drawn or undrawn depending on needs/objectives. Insulating division boards can be added to temporarily reduce an excessively large volume.

After 10–15 days, the worker bees will have emerged from the capped brood placed in the supers, and the wax foundation in the brood box will have been drawn and laid up.
A periodic rotation continues until the nectar flow: 2–3 frames of capped brood from the brood box are transferred into the centre of the two supers, and the 2–3 frames from the super from which the brood has emerged are moved back down into the brood box. The queen thus has enough space to lay, and because the ratio of open to capped brood area remains stable, the workers will not draw queen cells.
In the case of a strong nectar flow, the frame transfers are stopped and the beekeeper harvests the capped honey frames from the supers and replaces them with drawn but empty super frames. As the number of foragers has been greatly stimulated, the colony will easily populate the two supers and the insulating division boards can be removed. With the surplus brood frame, one can either create a nucleus or strengthen other colonies. In this way, varroa mites are removed from the colony. If the colony is not strong enough or the nectar flow too weak, one of the two supers is removed.

3.5 Method 5 : caging the queen

As soon as swarming fever has set in, the cage is inserted into a drawn frame in the middle of the brood nest, preferably near the top of the frame (cut the cage dimensions into the wax).
During an ongoing nectar flow, there must be enough honey comb available within the colony so that brood combs are not filled with honey.
Remove ALL queen cells
After 5 days, check again and remove any queen cells still present

After 14 days, check that the balance between capped cells and cells ready for laying has been restored and that swarming fever has been extinguished
Release the queen and check one week later that there are no queen cells and that the queen is active.

Observations en temps réel

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