How to protect an apiary from the Asian hornet?

Three measures have documented effectiveness: removing nests near the apiary, devices fitted to the hives — muzzles and entrance reducers — and electric harps. Autumn trapping around hives, very widely practised, gives results that ITSAP calls "often disappointing".

The priority: have nearby nests removed

ITSAP considers finding and removing nests the best solution to reduce pressure on an apiary. This is consistent with the draft national plan, which recommends focusing removals on nests "near apiaries", including in departments where the hornet is widespread and systematic removal is no longer the goal.

The difficulty is finding them. Tracking techniques — including radio telemetry, used in research — make it possible to trace hornets flying back from the apiary to their nest.

Removing an Asian hornet nest · Report a nest

Muzzles

A muzzle is a grid placed in front of the hive entrance. It lets bees through and blocks hornets, which are larger.

What studies establish: ITSAP finds muzzles proven to reduce colony stress while preparing for winter — that is, for what really matters, allowing the colony to keep foraging and building up its reserves.

What they cannot do alone: under very heavy predation pressure, a muzzle alone does not guarantee the colony's survival. Available studies suggest that in these conditions, electric harps do better at keeping colonies active. The muzzle is therefore a basic device to combine with others, not absolute protection.

When to fit it: on each hive, from mid-July, before the pressure builds up.

How to fit it: the muzzle must be far enough from the entrance — around 25 cm — for bees to be able to throw out drones and dead bees without suffocating the colony.

Advantage: it is the cheapest solution, and it needs no power supply.

Electric harps

A harp is a frame of live wires placed in front of the hives, which electrocutes hovering hornets.

Effectiveness: available studies show reduced predation pressure, mainly in areas of medium and heavy pressure. Under light pressure, the cost-benefit ratio is much less favourable.

When to install it: from mid-August, placed perpendicular to the front row of hives. Adding decoy balls to the wires improves catches.

Cost: about €300 each, power supply included. To limit spending without losing most of the effect, one harp for two to three hives is suggested; over a season, a ratio of one harp for four to five hives is also put forward.

Limitation: the device also catches other insects. It needs regular monitoring and maintenance.

Entrance reducers

Making the hive entrance smaller limits the number of points to defend and makes the guard bees' job easier. It is a simple, free measure that usefully complements the other devices.

It belongs to the "colony stress reduction tools", a category the draft national plan recommends rolling out widely in areas of medium to high density — that is, precisely where systematic nest removal is no longer the priority.

What works poorly: autumn trapping around hives

This is the least popular message, and the most useful.

ITSAP considers autumn trapping "often disappointing" for protecting apiaries. The reasoning is simple: catching workers near the hives does not reduce the nest's output, which keeps sending new hunters. You are removing a flow, not its source.

There is also a real ecological cost. Anses points out that non-selective traps — a plastic bottle with sweet bait — kill other insects essential to biodiversity and have almost no impact on the targeted nest.

This does not mean all trapping is useless, but that it belongs elsewhere: in spring, targeting founder queens, and in a coordinated way.

Spring trapping: under strict conditions

ITSAP's work from 2016 to 2020 in three departments shows that trapping founder queens does reduce the number of nests established — but at the cost of a considerable, sustained effort.

Two results are worth knowing before you start:

• Continuity comes first: trapping repeated without interruption for four years is twice as effective as the same effort over three years.
• The required density is high: the order of magnitude used is 59 traps per 3 km², i.e. about 350 metres apart.

In other words, isolated trapping by a single beekeeper on their own land has no measurable effect at the scale that matters. It is a collective action, coordinated across an area, or it is nothing.

As there are no fully selective traps or baits, ITSAP recommends limiting spring trapping to areas where predation genuinely threatens colony survival — in particular around apiaries that have suffered winter losses attributed to the hornet.

If you trap, choose funnel-entrance cage traps, with the bait separated from the capture chamber, which hold founder queens while letting small insects escape. Bell traps and bottle traps should be avoided because they are particularly unselective.

Trapping Asian hornets

Apiary protection calendar

These guidelines apply to an average season. Pressure starts earlier in the south-west of France: adapt to your local observations.

Frequently asked questions

Sources

1. ITSAP – French Bee Institute: how to set up a strategy against the yellow-legged hornet (in French)

2. ITSAP: assessing the effectiveness of spring trapping (28 March 2021), 2016-2020 study (in French)

3. Anses (2025), Envenomation by yellow-legged hornets and other hymenoptera in mainland France, request no. 2024-AST-0153, appendix 5 — warning about non-selective traps (in French)

4. Draft national plan to control the yellow-legged Asian hornet — consultation closed on 29 April 2026 (not adopted) (in French)

Information checked on 14/08/2026.