Practical Guide: 1.6.1 Brood interruption

A brood interruption is a deliberate suspension of brood production in honey bee colonies, used as a measure in Varroa management (e.g. for Varroa reduction or preparation for treatments). The following summary is based on the official Practical Guide 1.6.1 of the Swiss Bee Health Service.

Official Practical Guide (BGD / SSA) – Summary

Practical Guide: 1.6.1 Brood interruption

• Purpose: A controlled interruption of brood rearing is used to remove Varroa mites from the brood nest (they move onto phoretic bees) and to improve the effectiveness of subsequent treatments.
• Biological principle: Without brood, Varroa mites cannot reproduce further; during brood-free periods, mites in the colony are more accessible for diagnosis or treatment.
• Techniques for brood interruption – core approaches:
  • Progressive brood interruption: Removal of brood frames, e.g. for nucleus colonies, so that the remaining brood emerges within a few days and the brood chamber becomes brood-free.
  • Dadant-/Zander brood interruption method: Batch removal or relocation of brood to another colony; targeted creation of a brood-free space.
  • Brood interruption through space/frame management: Rearranging brood and food chambers so that the queen ceases laying (e.g. caging on foundation). These variants must be applied in a bee-appropriate and weather-dependent manner.
• Recommended timing: Depending on the regional beekeeping season, usually after the main nectar flow, when brood levels are declining and sufficient worker bees are present to achieve brood interruption.
• Benefits: Improved effectiveness of Varroa treatments (e.g. oxalic acid sublimation), fewer capped mites, and clearly defined diagnostic phases.
• Practical notes: Brood interruption methods require good knowledge of colony condition and current brood space; not equally suitable for all apiaries. Always consider weather conditions, food reserves, and colony strength.

► PDF of the official Practical Guide (DE)

► Official Practical Guide overview (bienen.ch)
Note: Section Varroa management → 1.6.1 “Brood interruption”.

Summary based on Practical Guide 1.6.1. Last review: 01/2026.

Learn more:

• Practical Guide 1.6.2 Trapping comb method
• Practical Guide 1.6.4 Total brood removal (TBR)
• Brood interruption for Varroa control
• Practical Guide 1.3.3 Oxalic acid sublimation