Beekeeping/Swarm Prevention

It is important to both understand the mechanisms that cause swarming, and the differences between swarm prevention and control.

Swarming

Swarming is a natural reproductive urge, which causes an increase in the number of colonies. While beekeepers try to minimise the swarming instinct, it can never be completely removed, as this would lead to a demise of colonies outside of a managed environment.

Swarms generally leave the colony the day after queen cells are capped, which happens around 8-9 days. This means that, during swarm season, beekeepers must inspect colonies every 8-9 days to avoid losing swarms.

There are a variety of factors involved in causing swarming, including:

Colony numbers (both brood and adult bees)
Queen Age
Presence of Drones
Time of year
Available space in the hive - both for brood, stores and adult bee movement.

However, the prime factor is the level of queen pheromone being received by adult worker bees during trophallaxis and interaction with the queen and other workers in the colony. A drop in the level of pheromone causes swarming tendencies - this being triggered by many of the factors listed above (e.g. an old queen produces less pheromone, a high level of workers 'dilutes' the available pheromone across the hive, etc).

Swarm Prevention

Swarm prevention involves taking steps to reduce or remove the swarming instinct. Some methods of swarm prevention are as follows:

Increase colony space

Adding more brood boxes or supers to a hive allows freer movement of bees, and increases the available space for laying brood, storing honey, and eases adult bee movement in the hive.

It is common for beekeepers to refer to the "Rule of 7's" when inspecting a hive - that is if there are 7 or more frames covered in bees, or filled with brood or stores, it is time to add more boxes as appropriate.

A variant of this technique is to swap around frames or boxes in a hive. For example, if in a double brood box, the top box is congested while the bottom box is empty, they can be swapped around - or some full frames can be exchanged with empty frames between boxes.

Removal of Queen Cells

In some circumstances, the removal of 'dry' (no brood present) queen cells or very young queen cells can delay the urge to swarm. However, this operation should not be performed more than 2-3 times in a colony, since a colony may eventually swarm anyway, leaving the original hive lacking a replacement queen. It is also important to inspect all frames very carefully, as a single queen cell is enough to trigger swarming.

Queen Clipping

Queen clipping involves clipping the tip off one of the queen's wings, making her unable to fly (or at least unable to fly great distances). This means that should a colony swarm, the queen will be unable to join the swarm, and eventually the swarm will return to the hive. This allows beekeepers to switch from a 9-day inspection cycle to a 14-day cycle, since action only needs to be taken before the new queen cells hatch (at which point either the queens will fight, or the virgin queen will swarm).

A clipped queen can still be lost, since having left the hive, she may be unable to return to it. However in many cases the loss of a queen is preferred to the loss of a queen *and* accompanying swarm.

Swarm Control

Swarm control refers to methods which prevent the swarming urge completely - usually by simulating some of the conditions of a swarm.

There are many methods of swarm control available, but they each derive from one of three 'original' swarm control methods.

Pagden Method

The Pagden method is one of the oldest and most commonly used swarm control methods.

Roof, supers, etc. are removed from the hive.
The brood box and floor are moved to a new site within the same apiary.
A new brood box, containing empty frames is placed on the original site.
The queen is found in the original hive, and moved to the new brood box.
Any supers are placed onto the new brood box on the original site.
Flying bees leave the old brood box, but return to the original site to join the queen.

The end result is as follows:

The original brood box is now queenless and contains no flying bees, so will not swarm and will go on to develop new queens.
The new brood box contains empty frames, the queen and flying bees. This simulates the completion of a swarm, due to the absence of brood.

The main variant of the Pagden Method is the Heddon Method.

Heddon Method

This variant aims to maintain the number of flying bees in the queen-right hive by 'bleeding' them into the original hive. This helps to support the honey harvest during a flow. The same procedure is followed as above, but with a minor change.

The original brood box is placed to the side of the original site, rotated by 90 degrees.
Flying bees leaving this box will return to the original site.
After 2-3 days, the box is placed on the other side of the original site, rotated 180 degrees.
Flying bees will return to the 'wrong' site, and instead find the entrance of the original site.
Finally, the hive is moved elsewhere in the apiary.
Again, flying bees will return to the original site.

Demaree Method

The Demaree method was originally designed to remove the need to split a colony in 2 when swarming, allowing all the bees to continue to work in one hive, improving yields.

Unlike the Pagden method, the Demaree method increases the height of a single hive, rather than adding a second hive to an apiary. This can be useful in terms of saving on buying new equipment, and in cases of limited space.

The Demaree method is more successful when performed before the first signs of swarming are seen - i.e. before queen cells are being built. However it will still work provided the queen cells are not too far developed.

The roof, supers, etc. are removed from the hive.
A new brood box with empty frames is prepared.
The queen is located, transferred to the new brood box, which is placed on the original floor.
A queen excluder is fitted, and 2 (or more) supers are added.
The original brood box is placed on top and the hive closed up.

Nurse bees will move up to the top box to care for the brood, while flying bees will move to the bottom box to continue foraging.

The absence of a laying queen will cause the top box to slowly empty as brood hatches. Brood will gradually build up in the bottom box.

The absence of queen pheromones in the top box (due to reduced trophallaxis, and lack of footprint pheromone) will cause the bees in the top box to begin to develop queen cells. The beekeeper now has several options:

Return after 5 days and destroy all queen cells - the lack of fresh larvae will prevent more queen cells being built.
Allow the queen cells to develop, taking them for use in other colonies.
Place a solid floor with it's own entrance (rotated 180 degrees) under the top brood box, treating it as a separate colony.

Care must be taken in all cases not to allow queen cells in the top box to hatch, or the presence of a virgin queen may cause the colony to swarm. However, there are some techniques which can be used to manage a 2-queen colony. In this case, a top entrance and second queen excluder would be needed under the top brood box to prevent the new queen laying in the supers.

When the bottom box begins to become crowded, the now empty top box can be substituted for the bottom box, repeating the procedure. It is not usually necessary to repeat this more than twice in a season.

The beekeeper should visit the hive every 5-7 days to remove the roof and release any drones which have emerged in the top box, since they will be unable to leave through the bottom entrance due to the presence of the queen excluder.

Snelgrove Method

The Snelgrove method is similar to the Demaree method in that it maintains a single 'tower' hive on one location - however it uses a special Snelgrove Board fitted with a series of doors to control the population in each part of the split.

The Snelgrove board is a double-sided crown board with bee-space above and below a central rim. Pairs of doors are placed on 3 sides of the board, with each pair giving access to the upper and lower parts of the hive.

The Snelgrove is similar to the Demaree, but with one extra step in the initial setup:

The roof, supers, etc. are removed from the hive.
A new brood box with empty frames is prepared.
The queen is located, transferred to the new brood box, which is placed on the original floor.
A queen excluder is fitted, and 2 (or more) supers are added.
A Snelgrove board is placed on top of the supers, entrances pointing to the sides and rear.
The original brood box is placed on top, and the hive closed up.

The following sequence of door manipulation is used to 'bleed' foraging bees from the top box into the bottom box, starting with all doors closed:

On the day of the split, open the top door on the left side of the hive. Previously oriented foraging bees will return to the original hive main door.
4-5 days later, the top-left door is closed, and the bottom-left and top-right are opened.
Previously oriented bees leaving the upper box (through the open top-right door) will return to the left side, and enter the bottom box. New foraging bees will orient to the top-right door.
4-5 days later the bottom-left and top-right doors are closed, and the bottom-right top-rear doors are opened.
Previously oriented bees, leaving the upper box (through the open top-rear door) will return to right side, and enter the bottom box. New foraging bees will orient to the top-rear door.
A few days later, the bottom-right door is closed.

The hive now consists of 2 colonies - the lower colony (with the original queen) using the front door, and the upper colony (queenless) using the rear door.

The beekeeper can either allow queen cells to develop and emerge in the top box, and treat this as a second hive, or remove any queen cells and the Snelgrove board, and manage the upper box as in the Demaree system (on top of supers), or add it back directly on top of the lower box as a double-brood hive. In these cases, due to the period of separation due to the Snelgrove board, the use of newspaper for merging is advised.

Horsley Method

Taranov Method

The Taranov method is named after its Russian inventor, G. F. Taranov. It attempts to mimic the behaviour of the bees wishing to swarm to separate out the young, swarming bees, from the older, non-swarming bees.

A flat board (such as a cover board) is placed 10cm from the front entrance to the hive, propped up on 2 legs so that one edge is level with the hive entrance.
The lower portion of the board is covered with a sheet that hangs down over the sides to create a dark space under the board. A strip of rough wood or piece of felt or carpet is attached under the board, 10cm from the edge closest to the entrance.
The frames are removed form the hive, and the bees are shaken evenly over the surface of the board.
The bees will walk up the board towards the top edge. Old, non-swarming bees, who have previously oriented to the hive entrance on foraging flights will fly over the gap and re-enter the hive.
The young swarming workers will move underneath the board, accompanied by the queen, and form a ball on the strip of wood or carpet placed there.
The 'swarm' ball can now be rehoused in a new hive elsewhere within the apiary.

It is best to do this operation late in the day, so that the urge of the newly swarmed bees to fly and return is reduced.