Practical Guide: 1.6.4 Total brood removal

Official practical guide – Swiss Bee Health Service (apiservice) – ApiSavoir translation

How can brood removal reduce varroa infestation while making use of the brood? Practical Guide 1.6.4 explains how to manage the production colony, set up a brood emergence hive and use the young bees that emerge.

1. Purpose and principle

Removing all the brood takes the varroa mites it contains out of the production colony. Brood frames from two to three colonies go into a shared emergence hive. The emerging bees can be used to form artificial swarms or strengthen existing colonies. Broodless units receive oxalic acid treatment. The guide describes this method as a replacement for the first summer formic acid treatment.

2. Conditions for use

Timing. Start after the last honey harvest in July. The method is particularly suited to stackable hives. The annual management plan in Guide 1.1 schedules the start of the first summer treatment without formic acid in the first half of July.

Health and mite levels. Use healthy donor colonies with a natural mite drop of no more than 7 mites per day in July. At higher mite levels, the emerging bees are often already damaged and are unsuitable for this use.

Equipment

Frames of foundation and hives for brood emergence and artificial swarms.
Queen introduction cages with candy plugs, feeders and sugar syrup.
Oxuvar 5.7% and protective equipment for spray application.

3. Procedure and recommendations

A. Set up the production colony on foundation

Find the queen and place her in a queen introduction cage closed with candy. Remove all frames. Recent pollen or food combs free of brood can be set aside and returned to the production colony or artificial swarms once the foundation has been drawn.
Fit the empty hive with frames of foundation. Introduce the caged queen and most of the bees. Promptly feed the production colony 1:1 sugar syrup.
Check that the colony is queenright no later than 7 days after brood removal. The guide also describes oxalic acid spraying within this period. Schedule the spray application for a time when the colony can be confirmed completely broodless.

Swiss package leaflet for Oxuvar 5.7%

Spring and summer spraying is for broodless units outside the nectar flow. Check the actual brood status before spraying. Eggs or any other brood stage make treatment with Oxuvar contraindicated. The seven-day deadline still applies to the queen check.

Prepare the spray solution according to the leaflet. When treatment is indicated, apply 3–4 ml per bee-covered side of a comb. The volume per trigger pull depends on the sprayer. Follow the protective equipment instructions and the restrictions on combs used for honey production in the current season.

Swiss package leaflet (German PDF) · Swiss package leaflet (French PDF)

B. Set up the emergence hive and use the young bees

Combine the brood frames and old food combs from two to three donor colonies in a new hive. Leave about a palm-sized patch of bees on each frame.
Plan for at least 3 km between the emergence hive and the production colonies. The French original gives this as a minimum and the German original as an ideal distance. Open the entrance immediately and keep it narrow. Ensure an adequate food supply.
After 9 days, take most of the young bees to form artificial swarms or strengthen existing colonies. At the same time, remove all queen cells from the emergence hive to prevent a heavily infested swarm from leaving.
After 3 weeks, use the remaining bees to form more artificial swarms. Melt down all the combs from the emergence hive.

The guide refers to 1.4.2 for forming artificial swarms. For overwintering, 1.6.4 gives a target of about 2.5 kg of bees per artificial swarm. It calls for oxalic acid treatment once all the brood has emerged or when artificial swarms are formed. Every unit treated with Oxuvar must be completely broodless. This also applies to existing colonies that have been strengthened with young bees.

C. Continue varroa management

Plan for the regular second summer formic acid treatment. Guide 1.1 schedules its start by mid-September. Guide 1.6.4 gives a narrow exception for very isolated apiaries with low natural mite drop and regular monitoring. Follow the annual plan for winter treatment.

4. Precautions and limitations

Important points from the Swiss Bee Health Service

If a notifiable brood disease is suspected, contact the apiary inspector before combining or moving combs and bees.
If a colony has a natural mite drop of more than 7 mites per day in July, exclude its brood from this method.
Keep the rapidly growing emergence hive well supplied with food and remove all queen cells on day 9.

5. Key points

After the last honey harvest in July, select healthy donor colonies with no more than 7 mites per day.
Set up production colonies on foundation and feed 1:1 syrup. Check queen status within 7 days. Confirm broodlessness before spraying Oxuvar.
Combine brood from two to three colonies. Use emerging bees on day 9 and after 3 weeks. Aim for about 2.5 kg of bees per artificial swarm intended for overwintering.
Melt down all emergence hive combs and plan follow-up treatment according to the annual plan.

6. Official source

Swiss Bee Health Service (BGD / SSA / apiservice)
Practical Guide 1.6.4 – Total brood removal with brood utilisation (ApiSavoir translation of the German and French originals)
Version: V 2605
ApiSavoir source review: 12 November 2026 (German and French)

Original BGD practical guide (German PDF)

Original SSA practical guide (French PDF)

7. Related articles

Application notice

This summary is provided for information purposes and does not replace the official Bee Health Service guide. Before practical application, consult the current product information, authorisation conditions and safety instructions.

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