Practical Guide: 1.6.2 Trapping comb method
Official practical guide – Swiss Bee Health Service (apiservice) – ApiSavoir translation
How can varroa mites be removed from a colony by targeting just a few brood combs? Practical Guide 1.6.2 explains how to let the queen lay on three trap combs in succession and when to remove each one.
1. Purpose and principle
The queen keeps laying and is moved to another trap comb every seven days. The rest of the brood is capped and emerges. The trap combs then provide the brood cells in which the mites can reproduce. Melting down the removed combs kills the mites trapped inside.
When the method is carried out as described, the Swiss Bee Health Service estimates that about 20% of the original mite population remains. The trap-comb method itself uses no veterinary medicine.
2. Conditions for use
The guide describes a system with one trap comb at a time. The method can also be used between nectar flows. For the first summer treatment without formic acid, the annual management plan in Guide 1.1 schedules the start in the first half of July.
Equipment
- A frame cage for one frame or a two-part trap-comb grid.
- Three brood combs to use in succession, with room for egg laying. An older comb with emerging brood is suitable for the first trap comb.
- For hives with several boxes, an optional queen excluder to limit the search for the queen to one box.
3. Procedure and recommendations
A. Rotate and remove the trap combs
Optional, 4–7 days before day 1. In a hive with several boxes, separate the boxes using a queen excluder. The first brood comb can be placed in the frame cage without the queen. Emerging bees free up cells for egg laying.
- Day 1. Confine the queen on trap comb 1, with emerging brood and as many empty cells as possible. Use the prepared comb if there is one.
- Day 8. Move the queen to trap comb 2. Hang trap comb 1, which contains mostly open brood, in the centre of the brood nest without its cage or grid.
- Day 15. Move the queen to trap comb 3. Hang trap comb 2 in the centre of the brood nest without its cage or grid. Remove and melt down trap comb 1.
- Day 22. Release the queen and leave trap comb 3 accessible to the bees. Remove and melt down trap comb 2 and any remaining capped drone brood.
- Day 29. Remove and melt down the last capped trap comb.
B. Assess infestation and plan follow-up treatment
Guide 1.6.2 describes trap combs as an alternative to emergency oxalic acid treatment for high mite levels in May or June. Guide 1.5.1 (V 2606) gives more precise criteria based on measured natural mite drop.
- Late May: At more than 3 and up to 7 mites per day, inclusive, the trap-comb method is one of the options. At more than 7 mites per day, use the emergency treatment in Guide 1.7.1 or 1.7.2.
- Late June or early July: At more than 10 mites per day, carry out emergency treatment or start the first summer treatment immediately. The trap-comb method is one of the options for this first summer treatment.
Carry out the second summer treatment with formic acid as usual, starting by mid-September under Guide 1.1. It keeps mite levels low until winter treatment and targets mites from possible reinfestation. The annual plan schedules winter oxalic acid treatment when the colony is broodless.
For later treatments with formic or oxalic acid, follow the Swiss package leaflet for the product used. Recommended beekeeping products from BGD and ZBF (German PDF)
4. Precautions and limitations
Important points from the Swiss Bee Health Service
- Check the colony for queen cells if using this method in May or June.
- With a two-part grid, cut a hole in the middle of the comb. Fit the first grid, then put the queen into the hole from the open side. Once she moves to the other side, fit the second grid. This lets her lay on both sides and reduces the risk of injury during introduction.
- When putting the queen into a frame cage, moisten her with a little water to slow her movements.
5. Key points
- Confine the queen on three trap combs in succession. Move her on days 8 and 15 and release her on day 22.
- Remove and melt down trap combs 1, 2 and 3 on days 15, 22 and 29. Remove any remaining capped drone brood on day 22.
- If natural mite drop is high, use the thresholds in Guide 1.5.1. The second summer treatment and winter treatment remain part of the annual plan.
6. Official source
Swiss Bee Health Service (BGD / SSA / apiservice)
Practical Guide 1.6.2 – Trapping comb method (ApiSavoir translation of the German and French originals)
Version: V 2412
ApiSavoir source review: 12 November 2026 (German and French)
Original BGD practical guide (German PDF)
Original SSA practical guide (French PDF)
7. Related articles
- Practical Guide 1.1: Varroa management plan
- Practical Guide 1.5.1: Measuring natural mite drop
- Practical Guide 1.6.1: Brood interruption
- Practical Guide 1.6.4: Total brood removal
- Brood interruption for varroa control
- Varroa control: Summer brood interruption
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.