How to introduce queens

The introduction of queens always entails a significant risk for the introduced queen. Some publications report failure rates of up to 50 %. For successful acceptance, all conditions must be optimal. The highest success rates are achieved when a young colony with a young queen is combined with an older colony. In general, favourable conditions must be deliberately created in order for a colony to accept an introduced queen.

1. Conditions for acceptance of a queen

• A queenless colony without open brood can successfully receive a new queen.
• Young bees accept a new queen more readily than older bees. If a queen is introduced into a colony that has been queenless for a long time and consists mainly of older bees, great caution is required. If the bees have started laying drone eggs (= laying-worker colony), the colony must be eliminated, as it will no longer accept any queen (shake all bees from all frames at least 100 m away from the apiary).
• A colony without open brood is unable to raise a queen on its own and will therefore be more inclined to accept a new queen.
• Large, populous colonies are more difficult to requeen. The larger the colony, the more pheromones the queen must produce so that the bees do not feel queenless.
• Empty spaces and brood attract young bees. To ensure that the queen is surrounded by young bees, the introduction cage should be suspended in an empty space between two brood combs.
• A calm and peaceful colony will accept a new queen more readily than an agitated and aggressive colony.
• A colony short of food is more likely to attack an introduced queen. In such cases, the hive should be fed before requeening.
• A colony affected by “swarming fever” is unlikely to accept a new queen.
• Introduce the queen without unnecessary delay (even though a queen can be kept in her shipping cage with attendants for up to a week, protected from light). If the queen does not lay for several days because she is confined in the cage, the intensity of her queen pheromones decreases.
• It is easier to introduce a queen outside the breeding period, i.e. in March, April, September, and October. In spring and autumn, pheromone production and colony strength are lower than in summer. The most favourable period depends on the introduction method used.
• In weather suitable for flight, the oldest bees are outside the hive, which facilitates requeening. Introducing the cage in the evening when the colony is calm, and releasing the queen the following day when the older bees are outside, promotes acceptance.
• During strong nectar flows, older workers are busy foraging, which also favours successful requeening.
• Robbing conditions are unfavourable, as bees are agitated.

Errors to avoid:

• Do not open the hive to check for the presence of the queen before one week to ten days.
• Do not introduce the queen together with her attendants in the cage.
• The candy in the feeding channel must not be hard. If the queen is released too late (no egg-laying for several days), pheromone production decreases.
• Do not forget to remove the safety tab from the cage.

2. Introduction methods

There are several methods for introducing queens. The choice depends on conditions and customary practice.

2.1 Replacement in a young colony

The safest approach is to introduce queens into young colonies, creating a situation similar to that of a secondary swarm. Young queens can be introduced into nuclei or artificial swarms. Procedure:

1. Prepare an artificial swarm with about 1.8 kg of bees on foundation (see summer nuclei), or five days before introduction create a nucleus with one food frame and two brood frames (open and sealed), well covered with bees. Strengthen the nucleus by shaking in bees from an additional brood frame; older bees will return to the mother colony.
2. Feed.
3. On day 5, remove queen cells.
4. Introduce the cage without attendants between two brood frames and remove the safety tab (if there is a risk the queen may fly off when attendants are removed, briefly dip the cage in a glass of water). Pierce the candy with a match; it must not be too hard.
5. Feed.
6. Check for egg-laying after one week to ten days.
7. The aim is to obtain a nucleus on six frames by the end of August.

2.2 Introduction into a colony queenless for 7–9 days

1. Make the colony queenless.
2. Wait 7 to 9 days.
3. Remove queen cells (the same result can be achieved by confining the queen to be removed in a closed introduction cage between brood frames; the presence of the old queen in the cage usually prevents emergency cell construction, but brood frames must still be checked).
4. Proceed according to points d to g of section 2.1 (do not open the hive before 7 days).

Tip: The queen can be changed immediately after formic acid treatment: make the colony queenless in the evening, start treatment the next morning, and introduce the new queen at the end of treatment (generally after 7–9 days). Advantage: egg-laying does not stop after treatment, as the new queen begins laying immediately.

2.3 Introduction with a small colony

The queen can also be introduced together with a small colony (small nucleus or reserve colony). A small colony can be directly united with a strong queenless colony. However, the arrival of a new queen may cause agitation; therefore adequate ventilation and water supply must be ensured.

Union with a queen excluder

A queen excluder is placed between the nucleus and the queenless colony. Once the bees have consumed the candy blocking the openings, the odours of both populations blend. The queen is generally well accepted after the excluder is removed.

Union with newspaper

Two damp sheets of newspaper with a few 2–3 cm slits are placed between the colonies to be united. As the bees chew through the paper, the colonies merge.

2.4 Replacement of a queen “by force”

This method is unreliable but may work at the end of the season.

1. Make the colony queenless.
2. Proceed according to points d to g of section 2.1 (do not open the hive before 7 days).

A more reliable method: using a mating nucleus (e.g. Apidea).

1. Make the colony queenless.
2. Wait 2 hours.
3. Place two sheets of newspaper on the queenless colony.
4. Make small holes in the base of the Apidea with a pen (variant: cut a board to accommodate the mating unit).
5. Open the bottom and place the mating unit on top (see image below).
6. Add a super and close.
7. Proceed according to points e to g of section 2.1 (do not open the hive before 7 days).

3. When should a queen be replaced?

Two situations:

1. Old queen; queen of an aggressive colony; queen of a weak colony; queen of a colony with chalkbrood: replace as soon as possible.
2. New queen after swarming; young but “inferior” queen (F3 to Fx):
   Given high winter losses, replacement in spring before the swarming period may be advisable for colonies that have overwintered.
   Two issues:

• Availability of queens early in the season (early May).
• Good honey yields and a queen of the current year may be difficult to reconcile, as the young queen lays intensively and much colony effort is devoted to rearing extensive brood rather than honey production. A solution is to restrict the colony to eight frames, for example.