Brood boxes after the Total Brood Removal (TBE), what options are there?

Total Brood Removal

Brood Nuclei after Total Brood Removal (TBR), What Options Are There?

Options, Setup, Mite Window, and Continuation as a Nucleus Colony

Total Brood Removal, or TBR, is an effective biotechnical measure for reducing mite infestation. All brood combs are removed from the colony. At this time, a significant portion of Varroa mites are in the capped brood and are removed from the colony with the brood combs.

The removed brood combs can either be melted down or collected in a brood nucleus or combined brood starter.

At Bee Pilot, we view the brood nucleus as more than just a storage place for removed brood combs. With proper setup and management, it can develop into a strong nucleus colony with a young queen.

Simultaneously, after all brood has emerged, a short and invaluable window without capped brood is created. This period can be specifically used to reduce mites, as oxalic acid only affects mites on adult bees, not those in capped brood cells.

There are various ways to further utilize a brood nucleus.

1. Allow the Brood Nucleus to Raise Its Own Queen

At Bee Pilot, this is often the most sensible and sustainable form.

The brood nucleus initially has no queen. If the brood combs have eggs or suitable young larvae, the bees can create queen cells to raise a new queen.

After emergence, the young queen must successfully complete her mating flight. She then begins laying eggs, and the brood nucleus becomes an independent nucleus colony.

Requirements

For this method to work reliably, several conditions should be met:

• At least one comb needs suitable young larvae or eggs.
• Sufficient numbers of bees must remain on the brood combs.
• The brood nucleus must be strong enough to care for large amounts of brood.
• Food supply must be ensured at all times.
• There must be enough mature drones available.
• There should be enough time before autumn for mating.

Advantages

• A new colony is created without purchasing a queen.
• The removed brood combs and emerging bees are fully utilized.
• The brood nucleus receives a young queen.
• The natural brood break can be used for targeted mite reduction.
• The new colony can later serve as a production colony, reserve colony, or for strengthening other units.
• There are no immediate costs for a mated queen.

Disadvantages

• The quality of the raised queen cannot be reliably predicted.
• The genetics come from the colony on which the queen was reared.
• The rearing can fail.
• The young queen can be lost on the mating flight.
• Poor weather or lack of drones can affect mating success.
• Considerable time passes until egg-laying resumes.
• A late TBR date can leave insufficient time for development.

Important: Do Not Check Too Early

A young queen needs time to emerge, mature, perform mating flights, and begin egg-laying. Too frequent or early disturbances can cause unrest and increase the risk of damaging the young queen or disrupting her mating process.

After an appropriate time, check if eggs and young brood are present. If broodless, timely decisions on whether to add a queen, conduct a queen test, or dissolve the unit must be made.

2. Add a Mature Queen Cell

Instead of allowing free-choice rearing, a mature queen cell from a chosen breeding line can be added.

Existing queen cells must be carefully removed before addition; otherwise, bees may prefer their own cells or multiple queens may emerge.

Advantages

• The maternal lineage of the new queen is known.
• Desired genetics can be more specifically selected.
• A mature queen cell is usually cheaper than a mated queen.
• The timing advantage over a freshly initiated queen cell can be several days.
• The natural brood pause is largely maintained.

Disadvantages

• The queen must still successfully mate.
• The mating risk remains.
• Paternal lineage is uncontrollable with open mating.
• The queen cell may be damaged during transport or insertion.
• Existing queen cells must be reliably found and removed.

This method is suitable for beekeepers looking to breed from selected colonies without using a mated queen.

3. Introduce an Unmated Queen

An already emerged but still unmated queen can be introduced. This is generally more challenging than introducing a mature queen cell or a mated queen.

Advantages

• The maternal lineage is known.
• The queen does not need to emerge in the brood nucleus.
• This method can offer a slight timing advantage.
• Unmated queens are cheaper than mated queens.

Disadvantages

• Acceptance of an unmated queen can be uncertain.
• She must still perform mating flights.
• The risk of loss during mating remains.
• The brood nucleus must have no queen and preferably no competing queen cells.
• Accurate timing for introduction is crucial.

This method is more suitable for experienced beekeepers able to accurately assess the brood nucleus’s condition.

4. Introduce a Mated Queen

To quickly and reliably develop a new colony, a mated queen can be introduced.

It must first be confirmed that no queen is in the brood nucleus. All queen cells must be removed. The new queen is typically introduced in a protected cage.

Advantages

• The brood begins much sooner.
• The risk of mating is eliminated.
• Genetics can be specifically selected.
• The development of the new colony is more predictable.
• This option is particularly suitable for a late TBR date.
• A valuable breeding queen can be introduced.

Disadvantages

• A mated queen incurs additional costs.
• Acceptance is not guaranteed.
• With existing queen cells or an overlooked queen, there is a high risk of loss.
• A rapid start to egg-laying shortens the window of complete broodlessness.
• Mite treatment and queen introduction must be carefully timed.

Those introducing a mated queen should plan the sequence of broodlessness, mite treatment, and introduction in advance.

5. Divide the Brood Nucleus into Several Nuclei

A strong enough brood nucleus can be divided into several units after much of the brood has emerged.

Each unit will then need either:

• Its own queen-rearing capability,
• A mature queen cell,
• An unmated queen, or
• A mated queen.

Advantages

• A large brood nucleus can produce several nuclei.
• Increases the apiary’s multiplication rate.
• Different queens or breeding lines can be used.
• Reserve colonies can be built for future losses.
• Excess bee population is effectively utilized.

Disadvantages

• Material needs rise significantly.
• Each unit requires sufficient bees, food, and a secure queen supply.
• Too small units may not develop sufficiently for winter.
• Mite load must be checked in each unit.
• Work and control efforts increase significantly.
• Later formation risks insufficient time for wintering.

Division is only sensible if the brood nucleus produces enough bees and sufficient development time remains.

6. Maintain the Brood Nucleus as a Reserve Colony

Not every brood nucleus must later become a regular production colony. It can also be specifically maintained as a reserve unit.

A reserve colony can later be used to:

• Save a queenless colony,
• Replace a lost queen,
• Strengthen a weak colony,
• Unite two weaker units,
• Provide a young queen for requeening, or
• Offset colony losses.

Advantages

• Provides additional operational security for the apiary.
• Queen problems can be resolved quickly.
• Weak colonies can be strengthened before wintering.
• A young queen is available as a reserve.

Disadvantages

• A reserve colony still requires a hive, food, care, and mite control.
• It binds equipment and a location.
• If not needed, future use must be reevaluated.

In larger operations, a well-developed reserve colony can be more valuable than immediate sale or hasty dissolution of the unit.

7. Dissolve the Brood Nucleus After Brood Emergence

Those not needing additional colonies can dissolve the brood nucleus after brood emergence.

The emerged bees can reinforce young colonies, nuclei, or weaker production colonies. Before uniting, it must be clarified if a queen is present and which queen should be retained.

Possible Uses for the Bees

• Strengthening a weak young colony
• Strengthening a nucleus
• Uniting with a reserve colony
• Forming an artificial swarm
• Supporting a late-formed colony
• Uniting with a production colony after honey harvest

Advantages

• No additional colony to maintain long term.
• The emerged bees are still utilized.
• Weak units can be specifically strengthened.
• Hive materials are freed up relatively quickly.
• Old brood combs can be melted down afterward.

Disadvantages

• The potential for a new colony remains unused.
• Dissolution and distribution cause additional work.
• Uncontrolled unification may lead to queen losses.
• Mites can be transferred to other colonies with the bees.
• Mite status must be clarified and possibly treated before distribution.

8. Form an Artificial Swarm from the Bees

After brood emergence, bees can be separated from the old brood combs and placed as an artificial swarm on new combs.

A queen is introduced to the artificial swarm. It is then fed and builds a completely new comb structure.

Advantages

• Complete comb renewal
• Clean restart on new foundation or starter strips
• Good opportunity to introduce a chosen queen
• Broodless bees can be specifically treated before restarting
• Old, dark, or contaminated brood combs can be melted down

Disadvantages

• High labor and material costs
• Additional queen required
• Sufficient feeding necessary
• The artificial swarm needs enough time for comb building and colony development
• Late formation can make wintering strength problematic

This variant combines the use of emerged bees with a complete renewal of the comb.

9. Directly Melt Down Brood Combs

Another option is to entirely forego forming a brood nucleus and directly destroy or melt down the removed brood combs.

This approach reduces the risk that mites within the removed brood later re-enter live colonies.

Advantages

• Very clear interruption of mite reproduction
• No further care for brood combs needed
• No risk of later reinvasion from the brood nucleus
• Consistent removal of old or dark combs
• Reduced risk of spreading brood diseases
• No additional queen required

Disadvantages

• The entire brood is lost.
• No additional colony is created.
• The potentially emerging bee population is not utilized.
• Melting large quantities of brood combs is labor-intensive.
• The loss of brood and wax can be economically significant.

This variant can be particularly effective for suspect, heavily contaminated, or very old brood combs. If there is suspicion of a reportable bee disease, relevant authorities or bee inspectors should be involved.

# Building the Brood Nucleus Properly

Regardless of the intended subsequent use, the setup already determines success.

Leave Enough Bees on the Combs

The removed brood combs should not be placed in the brood nucleus completely free of bees. There must be enough nurse bees to care for open brood and maintain the temperature of the brood areas.

The number of bees needed depends on the amount and condition of the brood, weather conditions, and size of the brood nucleus. Large amounts of open brood require particularly many nurse bees.

Use Only Healthy Brood Combs

Brood combs with suspicious, patchy, sunken, or foul-smelling brood should not be added to a common brood nucleus unchecked.

Combining brood combs from different colonies can also bring pathogens together. Suspicious brood conditions should therefore be clarified in advance.

Do Not Make the Brood Nucleus Too Large

A single extremely large brood nucleus is not automatically better. What matters is that the bees can completely occupy, warm, and care for all brood combs.

For very large quantities, it might be more sensible to create several brood nuclei. Units that are too weak are also problematic because they may not adequately care for the brood and later may not form a viable winter colony.

Adjust the Entrance

The entrance should initially match the colony’s strength and be kept relatively small. Brood nuclei contain many brood combs and food, but may initially have few oriented forager bees. This can make them particularly susceptible to robbing during periods of low nectar flow.

Certain treatment protocols may, however, require different entrance openings. The requirements of the used veterinary medicine and treatment system are therefore decisive.

# Why the Brood Nucleus Belongs in Another Location

At Bee Pilot, we believe a brood nucleus should ideally be moved to a different apiary, preferably outside the previous flight radius.

There are several important reasons for this.

Less Return Flight to the Mother Colony

If the brood nucleus remains at the original site, many older bees return to their original colony.

This results in significant loss of bee population from the brood nucleus. This is particularly critical when large open brood areas need care or high-quality queen cells need to be maintained.

While young hive and nurse bees orient themselves later, the brood nucleus should have a robust bee population from the start.

Better Care for Brood and Queen Cells

The more suitable nurse bees remain in the brood nucleus, the more reliably brood areas and queen cells are cared for.

Especially in queen rearing, it’s not just crucial for a queen to emerge, but also that the chosen larvae are well-nurtured from the start.

Reduced Risk of Mite Invasion

Significant numbers of Varroa mites from the production colonies are initially present in the brood nucleus. As bees emerge, mites leave the brood cells and sit on adult bees.

If such bees fly into or return to treated production colonies, they can reintroduce mites. A spatially separate location can reduce this risk, even though complete avoidance is not ensured.

Less Drifting Between Multiple Units

When setting up multiple brood nuclei at one location, hives should be distinctly different and not closely aligned in a straight row. Different orientations, spacing, and visual markers can reduce drifting.

# Feeding: One of the Most Important Points

Despite large quantities of bees and brood, a brood nucleus may only have small food reserves. Simultaneously, large amounts of larvae require nourishment until all brood emerges.

Especially during periods of low nectar flow, food consumption can be significant.

Therefore, reserves should be checked from the start. The brood nucleus must not experience any food shortages.

What to Consider When Feeding

• Check food reserves when setting up.
• Provide any available, healthy food combs.
• Feed early and appropriately if needed.
• Avoid spilling large amounts of food openly.
• Keep entrance small and defensible.
• Remove spilled food immediately.
• Monitor robbing mood at the site.
• Ensure enough empty cells for a later laying queen.

Excessive feeding can also be disadvantageous. If all available cells are filled with food, there is no space for the queen to lay eggs.

# Pollen and Protein Supply

Besides carbohydrates, nurse bees need enough pollen or protein to feed open brood and queen larvae.

In pollen-poor regions or during extended dearth periods, both food and pollen supplies should be evaluated.

A brood nucleus with extensive open brood areas but insufficient pollen reserves cannot optimally nurture the brood. Whether additional protein feeding is necessary depends on local supply conditions, colony strength, and colony health.

# The Critical Mite Window After Brood Emergence

Most Varroa mites are in capped brood cells during the brood phase. After all worker and drone brood emerges, mites temporarily sit on adult bees.

This timing presents a highly favorable treatment window.

Oxalic acid is ineffective in capped brood. It should be applied specifically during a truly brood-free phase.

When is the Brood Nucleus Truly Brood-Free?

Worker brood takes approximately 21 days to emerge from the egg. Drone brood requires more time. If capped drone brood is present during brood nucleus formation, it may still remain after the last worker brood has emerged.

Therefore, treatment should not only follow a calendar. Actual comb inspection is decisive.

Brood-free means:

• No capped worker brood,
• No capped drone brood, and
• No new capped brood from a young or introduced queen.

How We Work at Bee Pilot

At Bee Pilot, we usually allow the brood nucleus to rear its queen and then let it continue as an independent colony.

If possible, we move the brood nucleus to a different location. This keeps more nurse bees in the unit and reduces the risk of drifting and mite reintroduction into already treated production colonies.

After all old brood has emerged, we rigorously use the broodless window for mite reduction.

In our practice, we treat the broodless brood nucleus twice three days apart with oxalic acid before the young queen’s first brood is capped. We’ve had good experiences with this approach over many years.

However, it is essential: Oxalic acid preparations must be used only according to their current approval, package insert, and approved application form. Not every application form may be freely repeated. A drizzle treatment is not automatically suitable for repeated use. The specific application must always be checked against the veterinary product used.

# Monitoring Success After Treatment

Treatment should not be assumed automatically successful. Checking mite infestation post-treatment is essential.

Possible monitoring methods include:

• Monitoring natural mite drop using a tray
• Wash test
• Powdered sugar method
• Checking bees for visible Varroa mites
• Observing for deformed wings or other virus symptoms

With a notably high residual infestation, subsequent actions must be determined based on approved treatment plans and colony development.

# Common Mistakes in Brood Nuclei

Too Few Bees on the Brood Combs

If brood combs are removed with almost no bees, large brood areas might cool or be inadequately cared for.

Leaving Brood Nucleus at the Original Site

A significant portion of foragers may return to the mother colonies. The brood nucleus loses strength as a result.

Underestimating Food Supply

Large brood areas consume a lot of food. Food shortages can rapidly lead to brood loss and poor colony development.

Ignoring the Risk of Robbing

Weak entrance defense, open feeding, or spilled food can trigger robbing.

Failing to Check for Queen Rearing

Without young larvae, the brood nucleus cannot rear its queen.

Assuming Queenrightness Too Early

An emerged queen is not automatically a mated and laying queen. Only eggs or young worker brood confirm successful progress.

Calculating Brood-Free Periods Without Checking

Drone brood can remain capped longer. Additionally, a young or introduced queen may already have laid new brood.

Delaying Mite Treatment

If the first new brood is already capped, mites can again be in cells and not sufficiently reached by oxalic acid.

Forming the Unit Too Late in the Year

The later the brood nucleus is formed, the less time remains for mating, brood building, feeding, and wintering preparation.

Creating Too Many Small Units

Several weak units are not automatically more valuable than one strong, overwinterable nucleus colony.

# Decision Aid: Which Option Fits Which Goal?

Goal: An Additional Colony Without Queen Purchase

Let the brood nucleus rear its queen.

Suitable if:

• There is enough time,
• Suitable young brood exists,
• Enough drones are flying, and
• The risk of open mating is acceptable.

Goal: Targeted Genetics at Manageable Costs

Introduce a mature queen cell.

Suitable if:

• A selected breeding line is used,
• Mating success can still depend on location.

Goal: Quick and Planned Development

Introduce a mated queen.

Suitable if:

• The date is already advanced,
• Specific genetics are desired, or
• The risk of mating is to be avoided.

Goal: As Many Nuclei as Possible

Divide a strong brood nucleus into multiple units.

Suitable if:

• There is a large bee population,
• Sufficient equipment and queens are available, and
• Enough development time remains.

Goal: Reserve for Queen Losses

Continue the brood nucleus as an independent reserve colony.

Suitable if:

• Operational security is more important than immediate use as a production colony.

Goal: No Additional Colonies

Dissolve the brood nucleus after brood emergence and distribute the bees.

Suitable if:

• Existing nuclei are to be strengthened,
• But no further colony is to be overwintered.

Goal: Complete Comb Renewal

Form an artificial swarm after brood emergence.

Suitable if:

• New combs are to be built,
• A queen is available, and
• Enough development time remains.

Goal: Maximum Hygienic Separation

Melt down the brood combs.

Suitable if:

• No multiplication is desired,
• Old or suspicious combs are to be removed, or
• Brood utilization does not fit the operational concept.

# Yes, TBR with Brood Nuclei is a Material Battle

TBR with consistent brood utilization requires significantly more material than a simple treatment within the existing colony.

Depending on the operation, necessary items include:

• Additional hives,
• Bottom boards and covers,
• Frames,
• Feeding equipment,
• Queen excluders,
• Transportation options,
• Additional locations,
• Possibly queens or queen cells, and
• Time for monitoring, feeding, and mite management.

Therefore, it quickly leads to a material battle.

However, at Bee Pilot, we believe this effort is worthwhile. Production colonies are significantly relieved from Varroa mite burdens through brood removal. Simultaneously, a new colony with a young queen can emerge from the removed brood.

The material expenditure is not just extra ballast. The used hives and frames develop into new nuclei or reserve colonies and can secure the colony stock in the long run.

# Conclusion

A brood nucleus is not merely a byproduct of Total Brood Removal. It can become a valuable part of the entire beekeeping operation.

Fundamentally, there are several possibilities:

• Let it rear its queen,
• Add a queen cell,
• Introduce an unmated queen,
• Introduce a mated queen,
• Divide the brood nucleus,
• Maintain it as a reserve colony,
• Use the bees later for strengthening,
• Form an artificial swarm, or
• Consistently melt down the removed brood combs.

At Bee Pilot, continuing as an independent colony with a raised queen has proven especially successful.

The combination of a separate location, enough nurse bees, secure feeding, successful rearing, and the rigorous use of the broodless phase offers, from our perspective, the greatest advantages.

The effort is significant, and the amount of material needed should not be underestimated. However, the stress is worthwhile in our experience: Production colonies are relieved, the removed brood is meaningfully used, and young colonies with good development potential emerge.

It’s crucial not to leave the brood nucleus to fend for itself. It should be planned, monitored, and managed like any other bee colony.

---

Digitally Document Brood Nuclei, Treatments, and Colony Development

Try now for free!