How to prevent swarming: factors, methods and control

When a colony swarms, the queen and up to 60 % of the worker bees leave. It is the natural mechanism of species propagation, but for the beekeeper it means losing production, being left with a weakened colony, and above all, losing genetic control: the virgin queen that remains will mate with any drones available, not those chosen by you. Controlling it means anticipating six known factors.

In this guide

• what it is and why to control it;
• the six factors that trigger it;
• the methods to control it;
• what to do according to your apiary size;
• artificial swarming and divisions.

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Swarming is a natural and fascinating process in the life of bees. This phenomenon occurs when a colony reaches a considerable size and decides to divide to establish a new colony. Although it is an essential behaviour for the survival of bees, it presents a significant challenge for beekeepers, as it reduces the population of the original hive and, consequently, its honey production. In this article, we explore advanced methods and practical strategies for managing and controlling swarming, taking into account key factors such as genetics, feeding, hive structure and population management.

What swarming is and why to control it

Biological Importance of Swarming

Swarming is the natural method of species propagation for Apis mellifera. Through it, colonies divide and establish themselves in new locations, thus ensuring the continuity of the species. This process is mainly triggered in spring, when the colony grows and external conditions are favourable.

During swarming, the original queen and up to 60% of the worker bees leave the hive to establish a new colony. The original hive remains with a new queen developing in situ. Although swarming is essential for nature, in beekeeping it represents a loss of resources and honey production, making its control a priority for many beekeepers.

Why is it important to control swarming?

For a beekeeper, swarming presents both an opportunity and a challenge. In their natural environment, bees swarm to expand and perpetuate the species. However, in a managed apiary, uncontrolled swarming can lead to several problems affecting hive productivity and stability. These are some of the main reasons why controlling swarming is important:

1. Loss of Productivity: When a swarming colony divides, the original colony loses a substantial number of worker bees, significantly reducing honey, pollen and other apicultural production. This can be a major setback for the apiary’s economy, as the colony takes weeks to fully recover.
2. Risk of Weak Colonies: The departure of a large proportion of bees and the original queen can weaken the mother colony, leaving it vulnerable to disease, pests and climatic changes. A weakened colony requires more time to stabilise and has reduced chances of surviving adverse conditions.
3. Loss of Control over Reproduction and Genetic Selection: When swarming occurs without control, the original colony is left with a virgin queen in development. This new queen will need to mate, but the beekeeper cannot ensure she mates with drones from the same genetic line, which may dilute selected traits such as gentleness, resistance or productivity. Moreover, if queen mating fails, the colony may become queenless, compromising its stability and survival. This reduces control over genetic quality and performance in future generations.
4. Increased Workload: Uncontrolled swarming forces the beekeeper to undertake additional recovery work, either by capturing swarms or reorganising weakened colonies. This work does not always yield good results and may distract the beekeeper from other important management tasks.

In summary, controlling swarming enables the beekeeper to maintain a stable population, maximise honey and other product yields, and manage the apiary more efficiently and sustainably. Throughout this article, we will explore detailed strategies and advanced techniques to help beekeepers effectively manage swarming.

The six factors that trigger swarming

Understanding what factors can induce swarming is fundamental to applying preventive strategies and managing it effectively.

Population Imbalance and Role of Nurse Bees

At the beginning of spring, an increase in young bees (nurses) in relation to active brood triggers the construction of queen cells. This imbalance occurs because nurse bees need to be occupied and tend to stimulate new queen rearing when there is an excess. Maintaining an adequate balance of open brood and nurse bees can help control this impulse.

Queen Age and Pheromone Production

The queen is key to colony stability. Older queens produce less pheromone, which may cause workers to perceive the colony as queenless, encouraging the creation of new queen cells. Replacing queens at regular intervals, especially in large apiaries, helps maintain a constant pheromone flow and reduces the swarming impulse.

Brood Blockage

Brood blockage occurs when the colony is completely occupied with brood, pollen and honey, leaving the queen with no space to lay eggs. In spring, when blooms are at their peak, it is easy for the colony to become saturated. Providing space in time, either with wax foundation or by transferring capped brood to other colonies, can reduce the risk of swarming.

Rapid Population Growth and Reduced Pheromone Dispersion

A rapid population increase can reduce pheromone dispersion within the hive. This creates a perception that the colony is queenless that triggers the onset of swarming. Therefore, regulating hive population size is fundamental to maintaining cohesion within the hive.

Abundance of Food in the Field

During protein-rich nectar flows, such as oilseed rape or eucalyptus, the high protein content of the pollen stimulates accelerated brood production. This rapid growth can trigger swarming if not properly managed. In such cases, the use of pollen traps is recommended to limit pollen intake and reduce brood rearing.

Genetics: Do Not Split Colonies with Swarming Tendencies

One of the most common mistakes is breeding from colonies that have already swarmed, thus perpetuating a genetic tendency towards swarming. Instead, selecting and breeding from colonies less prone to swarming can significantly reduce swarming in the apiary. Saturating the area with queens from these lines can help establish a more stable and manageable apiary.

Methods for controlling it

There are various strategies that can be applied to prevent and manage swarming. Here are some methods based on practical experience and field observations.

Population Control Through Smoking and Removal of Excess Bees

During intense nectar flows, such as oilseed rape, removing excess bees helps keep the population under control. This process involves smoking the hive until bees rise to the lid, then removing them in clusters. This allows for a reduction in density without affecting productivity. These clusters of bees can be used to strengthen weaker hives or to establish new hives.

Solid Feeding in Spring and Use of Corks

Overfeeding in spring, especially with liquid feed, can stimulate population growth and trigger swarming. In certain cases, it is recommended to use solid feed, which provides bees with resources without encouraging excessive brood rearing. Additionally, using cork as insulation helps maintain a stable temperature within the hive, facilitating brood incubation without causing excessive growth.

Transfer of Sealed Brood

Transferring frames containing capped brood to weaker hives is a technique that helps reduce population in strong colonies and strengthens those with fewer bees. This practice helps balance hive density and is particularly useful in spring.

Introduction of Frames with Wax Foundation

Adding frames with wax foundation in the brood chamber provides additional space for the queen to lay eggs, preventing brood block and reducing hive pressure. This strategy is especially useful during heavy nectar flows, as it maintains bee activity without causing hive saturation.

Removal of Old Queens

Old queens produce fewer pheromones and are more likely to contribute to swarming. Replacing queens regularly maintains adequate pheromone production and reduces the risk. Before removing a queen, make sure recent brood is present, so the colony can raise a replacement if necessary.

According to the size of your apiary

The size of the apiary influences management techniques and swarming control. Here are some adapted approaches:

• Small Apiaries (1-10 hives): In small apiaries, manual management is easier. This includes checking for queen cells and removing them if a new queen is not desired. Queen excluders and intermediate frames may also be used to control population density.

Additionally, in small apiaries, it is easy to detect when a hive begins to show signs of overcrowding and swarming risk. In such cases, adding supers and improving ventilation can be key to reducing internal stress and heat. It is recommended to open the hive entrance and, if possible, create ventilation gaps, which allows air circulation and reduces the swarming impulse. These practices, combined with regular monitoring of swarming signs, help maintain stability in small hives and maximise their productivity.

• Medium-Sized Apiaries (10-100 hives): For medium-sized apiaries, the use of bee packages and transfer of sealed brood are ideal for redistributing population and preventing swarming in strong colonies.
• Large Apiaries (+100 hives): In large apiaries, genetic management is essential. Regular queen replacement and selection of genetic lines less prone to swarming reduce the need for manual interventions and facilitate overall apiary management.

Artificial swarming and colony splits

Artificial swarming is a strategy that allows the beekeeper to divide hives and prevent natural swarming. Here are some effective techniques:

Equal colony split without finding the queen

This method involves dividing the parent hive into two or more colonies without searching for the queen, then completing each with wax foundation. Subsequent inspection will identify which colony retained the queen.

Unequal colony split after finding the queen

In this case, the queen is located and left in the parent hive, while brood frames and bees are distributed into nucleus colonies that will be moved to a new apiary.

Fanned Partitioning

This method allows dividing one or more parent colonies into multiple nucleus colonies arranged in a fan pattern to balance forager population among the new hives. The nucleus containing the mother queen is usually most favoured, while the others develop a new queen.

6. Regular Monitoring and Early Detection of Swarming Signals

Preparation in Spring

Frequent spring inspections are recommended to identify signs of swarming. Checking for queen cells and monitoring population density every 10–15 days are fundamental practices, especially during major nectar flows such as oilseed rape or eucalyptus.

Regular Supervision and Early Detection

Observing the hive for early signs of swarming, such as restless bee behaviour or the formation of a bee beard at the entrance, allows timely intervention. Detecting these signs in time facilitates the removal of queen cells or adjustment of population before swarming occurs.

Recognising early signs of swarming is essential for timely action. In addition to the appearance of queen cells and increased population, external signs may also indicate an imminent swarming event:

• Idle, honey-filled foragers on the combs: Forager bees that have filled their honey stomachs and cannot deposit the nectar tend to remain in the hive, appearing bloated. This visual symptom indicates the hive is saturated and at risk of swarming.
• Bees forming a beard at the hive entrance: When the hive is overcrowded or internal heat is excessive, worker bees exit and cluster together forming a ‘beard’ at the hive entrance. Although not all swarming hives form a beard, it is a useful indicator for beekeepers, particularly in spring and summer.

Quick Summary of Key Points

• Maintain population balance: Control the ratio between nurse bees and brood.
• Control colony size: Use smoking and bee packages during intense nectar flows.
• Replace old queens: Renew queens regularly to maintain pheromone flow.
• Add space with wax foundation frames: Prevent blockage of the brood chamber.
• Apply techniques according to apiary size: Adapt control methods to the scale of your operation.
• Regular supervision in spring: Conduct frequent inspections during periods of high swarming risk.

Conclusion

Controlling swarming is an art that requires observation, understanding, and the application of a combination of management techniques adapted to each context. With well-implemented strategies, beekeepers can prevent bee loss, maintain stable honey production, and manage healthy hives. This article provides a comprehensive guide for beekeepers of all levels, helping them manage their hives effectively and understand the importance of swarming in the life cycle of bees.

Frequently asked questions

Continue reading

• Expanding your apiary, swarming on your terms.
• How to identify types of queen cells, to know what you are observing.
• Supersedure queens, which is not the same as swarming.
• How to introduce a mated queen, if you choose to renew.